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Increasing power demands in data centers demand high-efficiency, high-density power-conversion solutions.

Figure 1 shows a block diagram of power distribution inside an IT tray. A 48V bus bar goes down the back of the rack to distribute power to the IT trays. Inside each tray is hot-swap or e-fuse circuitry to limit inrush current during tray plug-in and to protect the upstream rack during tray failures. Intermediate bus converters (IBCs) convert 48V to the second-stage voltage, usually 12V or 6V. Final-stage multiphase buck voltage regulators complete power delivery by converting the second-stage voltage to the loads, with the majority of power going to sub-1V, high-current processors. In this edition of Power Tips, I will focus on the 48V IBC, covering design considerations, comparing topologies, and discussing system trade-offs of various approaches.

Figure 1 48V IT tray power distribution. Source: Texas Instruments

The IBC power distribution network offers a wide range of power-conversion approaches inside an IT tray (Reference 1). As the system architect, you have three main design choices:

• A modular or discrete solution (also known as chip-down design).
• Regulated, unregulated (also known as fixed ratio) or semiregulated IBC operation.
• The second-stage bus voltage to maximize system performance.

When selecting a modular or chip-down design power converter, your main trade-off will be power density vs. board design flexibility. Power modules, as shown in Figure 2a, are highly optimized solutions built on high-layer-count printed circuit boards (PCBs) (usually more than 16), offering prequalification and the highest power density. The drawbacks of power modules are a lack of flexibility, with fixed footprints and set features, as well as a higher cost per watt.

Chip-down designs, as shown in Figure 2b, are highly flexible solutions that offer footprint and feature freedom, with a lower cost per watt in high-volume production. Their drawbacks include longer upfront time and greater cost investments to qualify the design.

(a) (b)

Figure 2 48V IBC design examples of modular (a) and chip-down design (b) approaches. Source: Texas Instruments

When considering the output regulation of the IBC, your choice depends on two main factors: the load being powered and the operating range of the IBC’s input bus voltage. When the IBC directly drives 12V loads such as cooling fans, hard drives and Peripheral Component Interconnect Express cards, only a fully regulated output voltage (Reference 1) will ensure component safety. In modern data centers, the tray voltage has a more stable, narrow range, typically 40V to 60V. This narrow input range gives you the option to use higher-efficiency and higher-power-density fixed-ratio or semiregulated IBCs. The regulated second-stage voltage regulators following the IBC stage can absorb fixed-ratio IBC output voltage fluctuations.

Your third design choice is the second-stage voltage delivered by the IBC. Equation 1 determines system efficiency (ηsystem):

ηsystem = ηIBC x ηPDN x ηVR

For a given power load, decreasing the second-stage bus voltage will lower the IBC efficiency (ηIBC), because it must deliver more current at a lower voltage to provide the same output power. Similarly, for the motherboard power distribution network (PDN), which distributes current from the first-stage IBC to the second-stage voltage regulator, the PDN efficiency (ηPDN) will also decrease because of increased I2 x R ohmic losses. The benefit of a lower second-stage bus voltage is apparent when using final-stage, high-frequency, high-current voltage regulators with significantly reduced voltage-related switching losses. This results in higher second-stage efficiency (ηVR) and a potentially smaller size of the second stage.

Unlike a buck converter-dominated second-stage voltage regulator, a first-stage IBC has a wide range of power delivery approaches and thus a wider variety of power-conversion topologies available. In most modern IT applications, isolation for safety purposes is not required, so your power topology options increase further when you can consider transformerless options. Figure 3 shows four popular options for IBC module and chip-down designs.

The full-bridge converter shown in Figure 3a is a simple buck converter-derived transformer-isolated topology. The full-bridge converter’s strengths are ease of regulation and the ability to easily scale the intended output voltage by adjusting the transformer turns ratio for your chosen second-stage bus voltage. One drawback of the full-bridge converter is that transformer design is key to its performance, requiring a high-layer-count PCB that limits the topology to module-based designs. Another drawback of the full-bridge converter is that the primary devices are hard-switched, limiting power density and efficiency.

The transformer-isolated inductor-inductor-capacitor (LLC) converter shown in Figure 3b looks very similar to the full-bridge converter but uses an additional capacitor and two inductors to eliminate switching-related losses in the primary devices, enabling high efficiency and high power density (Reference 2). The LLC converter has the same transformer-related strength (an easily scalable output voltage) and weakness (it’s limited to module-based designs) as the full-bridge converter. The LLC converter operates with the highest efficiency at the resonant frequency set by the additional passive components (CR and LR), with efficiency decreasing as you move away from the resonant frequency to regulate the output voltage. For this reason, the LLC converter’s most common application in IBCs is fixed-ratio designs, always operating at the resonant frequency, ensuring the highest efficiency.

Two other popular topologies, the hybrid switched-capacitor (HSC) converter (Reference 3) shown in Figure 3c and the basic buck converter shown in Figure 3d, both offer benefits for chip-down designs because of their lack of AC-dependent power transformers. The HSC converter has a natural step-down ratio of 4-to-1, making it a strong candidate for high-efficiency 48V to 12V IBCs. The addition of flying capacitors limits the power density and hinders this converter’s operation in boost mode, making it a good fit for semiregulation, as regulating only occurs in step-down buck converter mode.

Because the HSC converter has a natural step-down ratio of 4-to-1, scaling the output voltage down further to an 8-to-1 6VOUT design (for example) is more challenging than it would be for the full-bridge and LLC converter options because the HSC converter must rely instead on a longer freewheeling period, requiring a larger output filter inductor, decreasing power density and efficiency.

The buck converter is the most common topology in power electronics, used exclusively in the second-stage voltage regulator, so it is natural to want to apply this simple and well-known approach to the IBC stage as well. The challenge with using a buck converter in the higher-voltage IBC application is that the power devices experience the highest voltage and current stresses when compared to the other topologies, limiting efficiency and power density.

(a) (b) (c) (d)

Figure 3 Popular IBC topologies: full-bridge converter (a); LLC converter (b); HSC converter (c); and buck converter (d). Source: Texas Instruments

Table 1 compares the different topologies and trade-offs.

  Full-bridge converter LLC converter HSC converter Buck converter

Module or chip-down design	Module	Module	Both	Both
Regulation type	Regulated	Fixed ratio	Semiregulated	Regulated
Efficiency	Medium	High	High	Low
Power density	Medium	High	Medium	Low
Output-voltage scalability	High	High	Medium	Medium
Complexity	Medium	High	High	Low

Table 1 Comparing IBC topology characteristics.

 With the maturation of gallium nitride (GaN) power devices (Reference 4), which have much lower switching-related charges compared to traditional silicon metal-oxide semiconductor field-effect transistors (MOSFETs), simpler topologies like the buck converter topology become more attractive and viable options for higher-voltage applications like IBCs. See Table 2.

  100V Texas Instruments GaN semiconductor 100V silicon MOSFET Difference

VDS (V)	100	100
RDS(on) (mΩ)	1.1	1.7	35% lower
QG (nC)	27	106	75% lower
QOSS (nC)	98	205	52% lower
QGD (nC)	2.5	26	90% lower
FOM1 = QG x RDS(on)	29.7	180.2	83% lower
FOM2 = QOSS x RDS(on)	107.8	348.5	69% lower
FOM3 = QGD x RDS(on)	2.75	44.2	93% lower
Package (mm x mm = mm2)	4 x 6.5 = 26 FET with gate driver	5 x 6 = 30 Discrete FET	13% smaller

Table 2 Comparison of 100V GaN and silicon-based IBC semiconductor options.

The IBC power distribution network offers the widest range of power-conversion approaches of the systems inside an IT tray for good reason. As power requirements and architectures rapidly evolve, the best way to optimize performance for 48V IBCs changes. And as additional variables such as highly improved GaN semiconductors get thrown into the equation, it becomes even more important to understand design considerations, topology comparisons and trade-offs.

References

1. Hsu, C., L. Olariu, S. Zou, et al. “48V Onboard Power Solution Requirements.” Open Compute Project, Version 1.0.0, Nov. 15, 2024.
2. McDonald, Brent. “Overview of a planar transformer used in a 1kW high-density LLC power module.” Texas Instruments technical article, 2025.
3. Li, C., and J.A. Cobos. “A Switched Capacitor and Autotransformer Hybrid Converter With DC Current in the Windings,” in IEEE Transactions on Power Electronics 37 (2), February 2022, pp. 1870-1884.
4. Gallium nitride (GaN) power stages, Texas Instruments.

David Reusch is a systems engineer on the data center team at Texas Instruments, specializing in power electronics. David has more than 20 years of experience in power electronics, ranging from cutting-edge gallium nitride (GaN) technology to high-reliability space-grade DC-DC converters. He received his B.S., M.S. and Ph.D. in electrical engineering from Virginia Tech.

 

Related Content

• Power Tips #151: Improving efficiency in 48V-input multiphase buck converters with GaN
• Power Tips # 141: Tips and tricks for achieving wide operating ranges with LLC resonant converters
• Power Tips #134: Don’t switch the hard way; achieve ZVS with a PWM full bridge
• Power Tips #127: Using advanced control methods to increase the power density of GaN-based PFC

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In modern engineering, precision fluid control is vital across industries ranging from electronics manufacturing to medical device design. Peristaltic pumps, with their distinctive squeeze-and-release mechanism, deliver exceptional reliability, cleanliness, and accuracy in fluid transfer. By preventing direct contact between the pump and the fluid, they ensure contamination-free operation while reducing maintenance demands.

This post explores the fundamentals of peristaltic pumping and how electric-drive systems help engineers achieve the perfect flow in today’s most demanding applications.

Peristaltic pump vs. electric peristaltic pump

A peristaltic pump refers to the general pumping principle: fluid is moved through flexible tubing by a rotating squeeze-and-release motion. This design ensures accurate flow and prevents contamination since the fluid never touches the pump components.

An electric peristaltic pump, however, is a specific implementation powered by an electric motor. The motor provides consistent speed, programmable control, and higher precision, making it ideal for industrial automation, laboratory dosing, and electronics manufacturing processes. While the term “peristaltic pump” covers the entire category, “electric peristaltic pump” highlights the modern, motor-driven versions that engineers rely on for efficiency and repeatability.

Figure 1 A sample of today’s compact electric peristaltic pump—this battery-operable low-voltage DC motor version demonstrates modern design efficiency. Source: Author

Peristaltic pumps vs. dosing pumps

A dosing pump is a broader category of pumps designed to deliver exact volumes of fluid at controlled intervals. Peristaltic pumps can serve as dosing pumps when paired with electric drives and programmable controls, but other pump types—such as diaphragm or piston pumps—are also used for dosing applications.

In short, all electric peristaltic pumps can function as dosing pumps, but not all dosing pumps are peristaltic. Understanding this distinction helps engineers select the right solution depending on whether the priority is contamination-free transfer, chemical compatibility, or ultra-precise dosing.

As a quick aside, it’s worth noting the distinction between DC-motor-driven and stepper-motor-driven peristaltic pumps. DC motors provide continuous rotation with simple speed control, making them cost-effective and compact for general fluid transfer.

Stepper motors, on the other hand, deliver precise incremental motion, enabling highly accurate dosing and repeatability. The choice between the two depends on application requirements: DC motors excel in straightforward pumping tasks, while stepper motors are favored in laboratory and industrial settings where precision is paramount.

Figure 2 A stepper-motor peristaltic pump delivers responsive start-stop and reverse operation, offers a wide speed range, and ensures reliability, thus meeting the accurate and dependable flow control demanded by precision instruments. Source: Author

The inner workings of peristaltic pumps

At the heart of a peristaltic pump is a simple but ingenious principle: fluid is transported by compressing flexible tubing in a controlled sequence. As rollers mounted on a rotating rotor travel along the tubing, they push the fluid forward in discrete segments, creating a smooth, continuous flow. Because the fluid remains fully enclosed within the tubing, there is no risk of contamination or contact with mechanical components, making this design particularly valuable in sensitive applications such as pharmaceuticals.

The internal structure of a peristaltic pump reflects this principle with elegant simplicity. A rotor fitted with rollers or shoes provides the pressure needed to move the fluid, while the tubing’s elasticity ensures it returns to its original shape after each cycle. The pump housing supports and guides the mechanism, ensuring consistent operation.

This combination of mechanical precision and material resilience allows peristaltic pumps to deliver accurate dosing, reliable performance, and easy maintenance—qualities that make them indispensable in modern engineering systems.

Figure 3 Drawing simply depicts the mechanisms of single-roller and multi-roller peristaltic pumps. Source: Author

As a closely related note, industrial peristaltic pumps differ from those used in general and medical applications. Industrial designs often employ shoe mechanisms to achieve higher pressures and rugged performance, making them suitable for chemical transfer, mining, and other heavy-duty environments where durability is paramount.

By contrast, general-purpose and medical pumps typically rely on roller mechanisms, which minimize friction, reduce energy consumption, and extend tubing life—qualities essential for precision dosing, sterility, and reliable operation in laboratory and healthcare settings.

And when powered by an electric motor, the same mechanism gains programmable control, variable speed adjustment, and enhanced precision. Electric peristaltic pumps transform the fundamental design into a highly versatile dosing system, capable of delivering exact volumes with repeatability. This evolution from a simple mechanical concept to an automated solution makes them indispensable in neoteric engineering environments where accuracy, efficiency, and reliability are non-negotiable.

Pulsed flow: Quick pointers for makers and engineers

Now to a few compact cues and practical insights to keep your designs flowing with precision. First off take note that motor choice sets the tone for performance: DC drives are cost-effective for simple transfer tasks like irrigation or fluid circulation, while stepper motors deliver the precision required for accurate dosing.

Roller mechanisms are especially suitable for medical and laboratory applications, since they minimize friction, extend tubing life, and provide gentle, contamination-free fluid handling. They also make an excellent choice for hobbyist projects, offering simplicity, reliability, and low maintenance for makers experimenting with fluid transfer.

By contrast, shoe mechanisms are designed for rugged industrial environments where higher pressures are needed, though they accelerate tubing wear. Tubing selection is equally critical; silicone ensures biocompatibility, PVC covers general transfer needs, and specialized elastomers withstand aggressive chemicals.

Now recall that roller pumps themselves come in single-roller and multi-roller designs. Single-roller pumps are mechanically simpler, lower-cost, and easier to maintain, making them suitable for basic transfer or hobbyist projects where flow smoothness is less critical.

Multi-roller pumps, by contrast, provide smoother, more continuous flow with reduced pulsation, which is essential in medical and laboratory applications where dosing accuracy and patient safety matter. While multi-roller designs increase complexity and cost, they extend tubing life and deliver higher precision, making them the preferred choice in food and beverage industries as well.

Also, electric drives add programmable control and variable speed, enabling integration with MCUs or PLCs for automation, while compact low-voltage battery-operated designs balance efficiency with portability in point-of-care devices. Notably, to mitigate the risk of power outages, contemporary electric peristaltic pumps for medical applications are frequently equipped with hand cranks for manual fluid delivery.

In today’s market, DC drive versions are available with more than just a regular DC motor—many include extra leads for speed control inputs (often via pulse width modulation), tachometer outputs, and other control/feedback signals. These additions give designers greater flexibility in monitoring, closed-loop control, and seamless integration with modern embedded systems, making even basic DC drives far more versatile than before.

Figure 4 Datasheet snippet highlighting a brushless peristaltic pump that delivers multiple features, including speed and direction control. Source: Binaca Pumps

Maker tip: PPM-controlled “digital” peristaltic pumps simplify automation by emulating the behavior of standard RC servo motors. Because the motor driver is integrated directly into the pump, you can skip the complex external circuitry usually needed to manage speed or direction. This lets you control the pump directly from a microcontroller’s digital pin using standard libraries—saving you both space and setup time (here is a practical example).

Frankly, when it comes to real-world control challenges, few are as nuanced as those involving peristaltic pumps. The core difficulty stems from two inherent characteristics of their operation. First, these pumps often run at very low speeds, sometimes down to a complete standstill depending on the application. Second, the motor experiences highly variable loads as the rollers engage and disengage with the flexible tube.

For most of the rotation cycle, the rollers move smoothly along the tube with minimal changes in torque or fluid pressure. However, at the points of disengagement and re-engagement, the system encounters sharp pulses in both torque and pressure.

That is, the combination of low-speed operation (which challenges velocity controllers) and cyclic load fluctuations (which creates non-linear disturbances) is exactly what makes these pumps “fussy” to control. Addressing these dynamics requires specialized motion control strategies—but that is a topic for another discussion.

Closing note: Peristalsis in engineering form

I have more to share but let me close with the fundamentals at this time.

Peristaltic pumps are a class of positive displacement pumps inspired directly by biology. Just as peristalsis in the digestive tract moves food through rhythmic muscle contractions, these pumps transport fluids by progressively deforming flexible tubing with rollers or shoes. The motion sweeps fluid forward, but because the swept length is always less than the tubing circumference, each rotation introduces a brief pause, resulting in the characteristic pulsed flow.

Designs vary between fixed and variable occlusion systems: fixed occlusion maintains a constant compression force, while variable occlusion allows adjustment via springs to fine-tune performance. Accuracy is further influenced by the slip factor, a correction term that accounts for incomplete tubing recovery and backflow, which can cause measured dispense rates to differ from theoretical values.

In peristaltic pump engineering, slip refers specifically to tubing recovery and backflow losses, which differs from the slip factor used in turbomachinery but serves the same purpose of correcting theoretical versus actual flow.

In essence, peristaltic pumps mirror a biological process with engineering precision—balancing simplicity, safety, and adaptability across a broad range of applications. In healthcare, they provide sterile infusion for IV therapy, dialysis, and precise drug delivery. In laboratories, they handle chemical dosing, reagent transfer, and bioprocessing where purity is paramount. Industrially, they manage viscous fluids, corrosive chemicals, and food-grade materials without risk of cross-contamination.

In the food and beverage sector, they support hygienic transfer of juices, dairy, and brewing ingredients. For hobbyists, they simplify aquarium maintenance, hydroponics, and small-scale brewing. In agriculture, they excel at nutrient dosing in irrigation and supplement delivery in animal farming. Their gentle, pulsed flow and hygienic design make them a versatile solution wherever controlled, reliable fluid handling is required.

As you explore these designs in your own projects, consider how roller choice, hose selection, occlusion type, and modern drive features can shape performance, and share your insights to keep the conversation on precision fluid handling moving forward.

T. K. Hareendran is a self-taught electronics enthusiast with a strong passion for innovative circuit design and hands-on technology. He develops both experimental and practical electronic projects, documenting and sharing his work to support fellow tinkerers and learners. Beyond the workbench, he dedicates time to technical writing and hardware evaluations to contribute meaningfully to the maker community.

Related Content

• Designing Motor Control: Key Aspects
• Designer’s guide: Motor control and drivers
• Mastering motor control: motor control 101
• Optimizing motor control for energy efficiency
• A primer on industrial motors and motor control

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Deepak Shankar, founder of Mirabilis Design and developer of VisualSim Architect platform for chip and system designs, has created this cartoon for electronics design engineers.

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Obtain tighter stop band impedance variance via the techniques detailed in this tutorial.

Input impedances presented by lowpass and highpass filters in their respective stop bands are usually not controlled and can vary quite widely. Sometimes though, we’d like to have a little better control of them.

For example, tee-configuration low-pass filters and high-pass filters exhibit input impedances and frequency responses which are typified in the following sketches:

Figure 1 A typical tee-configuration low-pass filter delivers non-ideal results.

Figure 2 A typical tee-configuration high-pass filter also delivers non-ideal results.

For tee-configuration filters, the presented input impedance in the passband tends toward the load resistance value, but in the stopband, the presented input impedance rises without limit. That essentially uncontrolled and rising impedance can create stability problems for some kinds of driving devices delivering input signals to such filters.

There is at least a partial remedy for this impedance issue possible, as follows:

Figure 3 A tee-configuration filter pair provides at least a partial remedy.

Using both a low-pass and high-pass filter, with each feeding its respective load, the input impedance becomes controllable both in the passband and the stopband of whichever filter you decide is the intended signal path. Input impedance and frequency responses would take on the following forms:

Figure 4 Controlled impedance filtering can improve stability.

The corner frequency impedance null doesn’t go away, but the input impedance both above and below that corner frequency tends to the load resistance values, chosen here as fifty ohms, which may help make a driving amplifier more stable.

John Dunn is an electronics consultant and a graduate of The Polytechnic Institute of Brooklyn (BSEE) and of New York University (MSEE).

Related Content

• Toward better behaved Sallen-Key low pass filters
• Simple state variable active filter
• A digital filter system (DFS), Part 1
• A digital filter system (DFS), Part 2

 

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As industrial environments rapidly evolve with the integration of operational technology (OT) and information technology (IT), the demand for seamless connectivity and reliable power delivery has never been higher. The proliferation of smart devices, such as sensors, controllers, cameras and robotic arms, has made data indispensable to modern factories and process industries.

To meet the increased demand, more industrial IoT (IIoT) device manufacturers are turning to Power over Ethernet (PoE) as a preferred solution, leveraging its unique ability to deliver both power and data over a single cable. This convergence is enabling smarter, more flexible and efficient industrial operations, while simplifying deployment and maintenance for end users.

Figure 1 Industrial environments are increasingly integrating operational and information technologies. Source: Microchip

What’s Power over Ethernet (PoE)?

Power over Ethernet (PoE) is a technology that allows electrical power and data to be transmitted simultaneously over standard Ethernet cabling. It was first introduced by PowerDsine in 1998; the company was later acquired by Microchip Technology. The Institute of Electrical and Electronic Engineers (IEEE) introduced the first IEEE 802.3af standard in 2003.

PoE was initially developed to power devices like IP phones and wireless access points without the need for separate power supplies. Since then, PoE standards have evolved to include IEEE 802.3 af/at/bt supporting higher power levels and a broader range of devices, making it a cornerstone technology for modern networking encompassing industrial automation and IIoT deployments.

Why IIoT manufacturers are turning to PoE

For IIoT device manufacturers, PoE offers a host of compelling benefits. PoE simplifies deployment by combining power and data in a single cable, eliminating the need for separate electrical wiring and reducing installation complexity and cost. It enables flexible placement of devices, allowing installation in remote, hard-to-reach, or hazardous locations where traditional power sources may be unavailable or cost-prohibitive.

PoE also supports unified network architecture, streamlining network design and making it easier to scale and adapt to changing operational needs. Reliability and compliance are enhanced, as standards-based PoE delivers safe, low-voltage DC power, supporting regulatory compliance and minimizing electrical hazards.

Additionally, offering PoE-powered devices can provide manufacturers with a competitive advantage in a crowded market by delivering a more convenient, integrated solution to customers.

Overcoming PoE deployment challenges in industrial settings

Despite its advantages, deploying PoE in industrial environments is not without challenges. One of the primary obstacles is the limited availability of PoE-enabled network infrastructure. Many existing industrial networks lack PoE switches, and even when available, these switches may not provide sufficient power on every port to support all connected devices.

The cost and complexity of upgrading network infrastructure can be prohibitive, especially in legacy facilities. Other challenges include limited access to power, as not all areas of a factory or plant have easy access to network cabling or power outlets, making device placement difficult. The high cost of power delivery can also be a concern, as retrofitting facilities to support PoE can be expensive and disruptive.

Compatibility concerns must be addressed to ensure that PoE-powered devices work seamlessly with existing network equipment, avoiding downtime and support issues. Finally, scalability is a challenge, as the number of connected devices grows, so does the demand for reliable, scalable power solutions.

Introducing PoE midspans: Supplementing network power

To address the challenge of limited PoE-enabled infrastructure, many industrial facilities are turning to PoE midspans, also known as injectors, to supplement network power where it does not exist. A PoE injector is a device that sits between an Ethernet port that is not supplying PoE and the powered device, injecting power into the Ethernet cable so that both data and power are delivered to the endpoint.

This approach allows manufacturers and customers to deploy PoE-powered IIoT devices without the need to replace existing switches or overhaul network architecture, making it a cost-effective and scalable solution for expanding PoE coverage in industrial environments.

Figure 2 PoE midspans inject power into the Ethernet cable. Source: Microchip

PoE industrial injectors vs. standard indoor injectors

While standard indoor PoE injectors are suitable for office or commercial settings, industrial environments demand more robust solutions. PoE industrial injectors are specifically designed to withstand the harsh conditions often found in factories, processing plants, and outdoor installations.

These injectors feature ruggedized construction, enabling reliable operation in environments with extreme temperatures, humidity, dust, and vibration. They support an extended temperature range, ensuring consistent performance in both hot and cold conditions.

Enhanced safety and compliance are also critical, as industrial injectors meet stringent safety and regulatory standards, providing low-voltage, standards-compliant DC power that minimizes electrical hazards. Industrial PoE injectors support higher power levels—such as IEEE 802.3bt up to 90 W—to accommodate demanding devices and are designed with robust surge protection, which is essential in industrial environments where electrical surges from machinery or harsh conditions are more common.

Flexible mounting options, such as DIN rail, wall, or rack installations, accommodate diverse deployment scenarios. Reliability and longevity are ensured through components and enclosures designed for continuous operation, providing long-term durability and minimal maintenance. These features are essential for maintaining uptime, safety, and performance in industrial settings, where environmental challenges and operational demands are far greater than in typical office environments.

Figure 3 Here is a visual comparison between standard indoor midspan (above) and industrial midspan (below). Source: Microchip

What to look for in a PoE solution provider

For IIoT device manufacturers and customers deploying PoE-powered devices, selecting the right PoE solution provider is critical. Proven compatibility is essential; the provider’s injectors should be tested and validated for seamless operation with a wide range of industrial devices, reducing the risk of downtime and support issues.

Flexible power options are important, with support for various power levels and device types to meet diverse application needs. Reliability and compliance should be prioritized, ensuring solutions meet industry standards for safety and performance, supporting regulatory requirements and minimizing risk.

Ease of installation is also key, with plug-and-play solutions that leverage existing Ethernet cabling to simplify deployment and reduce installation time. Rugged design is necessary for industrial-grade injectors, offering robust construction and extended temperature ranges for reliable operation in challenging environments.

Finally, strong technical support and post-sale service from the provider can help resolve compatibility issues and ensure long-term satisfaction. By prioritizing these features, manufacturers and customers can ensure successful, scalable, and reliable PoE deployments in industrial environments, unlocking the full potential of smart IIoT devices.

Alan Jay Zwiren is senior marketing manager of Microchip Technology’s Networking and Connectivity Business Unit.

Special Section: Smart Factory

• Rethinking machine vision in industrial automation

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Cirrus Logic has launched the CS82L4x series of analog front-end (AFE) chips for CIS and CCD sensors in scanners and industrial imaging platforms. Based on a redesigned SAR ADC architecture, the devices are said to offer faster scan times and enhanced efficiency, while an integrated RGB LED driver reduces design complexity.

The CS82L41, CS82L44, and CS82L46 provide one, four, and six channels, respectively, with a conversion rate of 24 Msamples/s per channel. With 16-bit resolution, the AFE ICs convert LED reflections from scanned objects into accurate digital representations. Per-channel signal conditioning includes reset level clamping, correlated double sampling, and programmable polarity, gain, and offset adjustment.

Operating from a 3.3-V supply, the CS82L4x series provides a scalable platform for multi-lens and multichannel scanning architectures across a range of imaging systems. The CS82L41 features an SPI control interface with CMOS output. The CS82L44 and CS82L46 offer SPI or I²C control interfaces, CMOS or LVDS outputs, and integrated sensor timing generation. All devices operate over a temperature range of −40°C to +85°C and come in QFN packages.

Samples are available now from Cirrus.

CS82L41 product page

CS82L44 product page

CS82L46 product page

Cirrus Logic 

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Power inductors in Vishay’s IHLP1212-EZ-1Z series come in low-profile 1212-size packages suited for space-constrained commercial applications. With a 3×3-mm footprint and profile options of 1.2 mm, 1.5 mm, and 2.0 mm, their electrical performance is comparable to larger devices.

The series includes 24 devices with typical DC resistance from 8.6 mΩ to 50.4 mΩ and inductance values from 0.22 µH to 3.3 µH. Rated saturation current reaches 14.3 A, while heating current extends to 11.1 A. Operating over a temperature range of −55°C to +125°C, the inductors are designed to handle high transient spikes without saturation.

IHLP1212-EZ-1Z inductors feature a powdered iron body that completely encapsulates the windings, eliminating air gaps and providing magnetic shielding to reduce crosstalk with nearby components. Their composite construction also offers strong resistance to thermal shock, moisture, and mechanical stress.

Designed for low-profile DC/DC converters, the inductors enable energy storage, noise suppression, and filtering across industrial, consumer, telecom, and medical applications. Samples and production quantities are available with lead times of 10 weeks.

IHLP1212-EZ-1Z product page

Vishay Intertechnology 

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A software option for Rohde & Schwarz vector signal generators supports Pulsar signal simulation testing in production settings. Pulsar is Xona Space Systems’ planned LEO satellite constellation for high-precision positioning, navigation, and timing (PNT) services. R&S SMBV100B and SMW200A generators equipped with the software allow engineers and manufacturers to test receiver compatibility as the constellation enters scaled deployment.

“Pulsar is designed to upgrade the global navigation infrastructure while remaining compatible with GNSS devices already in use today,” said Bryan Chan, co-founder and VP of strategy at Xona Space Systems. “Test and measurement solutions play an important role in enabling device manufacturers to evaluate compatibility as new signals become available. Rohde & Schwarz brings deep expertise in precision signal generation that helps make this possible.”

The SMBV100B and SMW200A vector signal generators will soon join Pulsar’s verified ecosystem program, which recognizes devices and test systems validated for compatibility with Pulsar signals.

Rohde & Schwarz 

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Intel has introduced its Core Series 3 mobile processors targeting budget laptops and essential edge devices. Built on the same 18A process node as the Core Ultra Series 3 platform, they are described as the first “hybrid AI-ready” Core series processors, supporting AI workloads up to 40 TOPS at the platform level.

The processor lineup includes seven variants, one without an NPU. Compared with five-year-old PCs, Core Series 3 delivers up to 47% higher single-thread performance and 2.8× higher GPU-based AI performance, based on Intel’s internal benchmarks. Beyond laptops, it brings these gains to edge deployments such as robotics, smart buildings, POS terminals, and smart metering.

According to Intel, Core Series 3 is designed for all-day battery life, with up to 64% lower processor power consumption. The devices support high-speed connectivity, including up to two Thunderbolt 4 ports, Wi-Fi 7 (R2), and Bluetooth 6. They also support up to 48 GB of LPDDR5X memory at 7467 MT/s or up to 64 GB of DDR5 memory at 6400 MT/s.

Core Series 3-based consumer and commercial systems will be available from OEM partners starting April 2026, with edge systems following in Q2 2026. An in-depth overview of Core Series 3 is available here. 

Core Series 3 product page 

Intel

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Anker Innovations has developed an AI audio chip for earbuds, called Thus, that uses NOR flash memory for compute-in-memory (CIM) processing. This approach supports several million model parameters across multiple workloads and delivers up to 150× more AI computing power for environmental noise cancellation compared with Anker’s previous flagship earphones.

NOR flash-based CIM reduces the required silicon footprint to about one-sixth that of SRAM-based alternatives, making it better suited for highly constrained consumer devices. Anker will integrate Thus into its upcoming Soundcore true wireless earbuds. The company also plans to bring neural-network AI to additional consumer devices, including mobile accessories and IoT devices.

The AI processor’s first disclosed feature, Clear Calls, improves voice clarity on calls by isolating the speaker’s voice from background noise. Unlike conventional environmental noise cancellation, which can struggle in loud environments, it uses an on-device neural network supported by eight MEMS microphones and two bone conduction sensors to separate speech from ambient sound. The result is clearer calls in challenging environments such as airports, bars, and busy streets.

Full product details will be announced at Anker Day on May 21, 2026, in New York.

Anker Innovations

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Circuits such as the design described here implement useful tools for a diversity of calibration and testing applications.

A two-wire loop current generator is a useful tool for the testing, calibration and commissioning of current-to-pressure (I/P) converters connected with control valves, actuators, etc. in process industries. Such product can also help calibrate the analog input modules of distributed control systems (DCSs) and programmable logic controllers (PLCs) by simulating process signals.

Wow the engineering world with your unique design: Design Ideas Submission Guide

In these and other applications, it is advantageous to generate a loop current which is linearly variable for precisely setting the desired current. A Design Idea published in EDN’s December 10, 2025 issue, although compact and otherwise excellent, does not support linearly variable current, since the output current relationship is Io=1.24/R1. R1 is adjusted to vary the output current, but since it is in the denominator of the equation, the resultant current variation is not linear.

Figure 1 describes a circuit where the variation of loop current is linear. Here, the loop current is directly proportional to the voltage set by potentiometer RV1. Moreover, this current can service a source or sink load up to 500 ohms without need for recalibration. These two requirements are essential for a loop current generator in process industries.

Figure 1 With this linearly adjustable two-wire current source, RV1 is adjusted to set the current, and either LOAD1 (source) or LOAD2 (sink) can be connected.

How does the circuit work? First connect a 24V DC supply, a DC ammeter and a load resistor—say, 200 ohms—at the source or sink side. In field applications, this portion is built into the I/P converter, DCS or PLC.

Two currents exist at pin 3 of U1A :

• I span=Vset/R5
• Through R4=(Io*R6)/(R4+R6)

The first current minus the second current = 0, as U1A is an operational amplifier.

Io is the loop current. Hence Vset/R5= (Io*R6)/(R4+R6). After rearranging, Io= (Vset/R5) * (1+R4/R6). Substituting the values, R4/R6= 99. Hence, Io= (Vset/R5)*100.

Thus, Io is directly proportional to Vset which is adjustable linearly by RV1. A multiturn potentiometer selected for RV1 will enable smooth and precise adjustment.

Other comments, in closing:

• U3 generates 5V DC.
• Q1 and U1A adjust the loop current Io proportional to Vset.
• R1 and Q2 set the current limit for Io at approximately 30 mA for safety reasons.
• The loop current is settable from 0.5 mA to 23.5 mA, which is sufficient for this application.
• For different current settings, select R3, R2 and R5 as per the equation given earlier for Io.
• And Q1 requires a heat sink.

Jayapal Ramalingam has over three decades of experience in designing electronics systems for power & process industries and is presently a freelance automation consultant.

Related Content

• Two-wire precision current source with wide current range
• A precision, voltage-compliant current source
• Precision current source

The post Linearly variable two-wire loop current generator appeared first on EDN.

Deepak Shankar, founder of Mirabilis Design and developer of VisualSim Architect platform for chip and system designs, has created this cartoon for electronics design engineers.

The post The system architect’s sketchbook: The pickleball protocol appeared first on EDN.

The traditional ASIC design model—focusing on relatively stable standards and well-defined functions—is now under pressure. That’s partly because AI workloads are highly diverse, compute-intensive, and tightly coupled to software behavior and system context. Consequently, ASICs, besides being application-specific, are now increasingly becoming system-specific.

Take the case of a custom chip for LLM inference, where the prefill and decode stages are now running on separate chips. So, there are two ASICs instead of one: the compute-intensive part of the application (prefill) and the memory-bandwidth-limited part of the application (decode). That shows how ASICs are increasingly becoming modular and disaggregated with cross-domain collaboration spanning architecture, packaging, and manufacturing.

Read the full article at EDN’s sister publication, EE Times.

The post The ASIC design remake in the AI era appeared first on EDN.

Deepak Shankar, founder of Mirabilis Design and developer of VisualSim Architect platform for chip and system designs, has created this cartoon for electronics design engineers.

The post The system architect’s sketchbook: GenZLens built in a dorm appeared first on EDN.

Simple math implemented in a (very) simple circuit. What’s not to like?

A very cool (also warm!) property of the base-emitter junction of (most) small signal BJTs is the ΔVbe temperature-sensing effect.  ΔVbe temperature measurement is aptly described and applied here by famed and forever remembered analog design guru Jim Williams (see page 7):

At room temperature, the Vbe junction diode shifts 59.16mV per decade of current. The temperature dependence of this constant is 0.33%/°C, or 198μV/°C. This ΔVbe versus current relationship holds, regardless of the Vbe diode’s absolute value.

Wow the engineering world with your unique design: Design Ideas Submission Guide

Rearranging Williams’ math, since 198uV=1V/5050, 198μV/°C per current decade works out to (the easier to remember…ha!) ΔVbe/°C = Log10(Current-ratio)/5050.  So, if we need any given ΔVbe/°C, the required

Current-ratio = 10^(5050 ΔVbe/°C).

For example, for ΔVbe/°C = 100uV, Current-ratio = 10^(5050 * 100uV) = 10^(0.5050) = 3.20

Of course, this trick also works for Fahrenheit, albeit with a different scale factor.  Since 1 °F = 5/9 of 1°C, for Fahrenheit the corresponding Current-ratio = 10^(9090 ΔVbe/°F).  Therefore, for the 100uV example, if ΔVbe/°F = 100uV, then Current-ratio = 10^(9090 * 100uV) = 10^(0.9090) = 8.11

Figure 1 shows this simple math implemented in a (very) simple circuit:

Figure 1 An ordinary BJT Q1 makes an accurate absolute temperature sensor in two different units (K and R).

Here’s how it works. Switch U1a applies alternating current ratio drive to sensor Q1 per Williams’ method.  The ratio is (approximately) Current-ratio = (1/R1 + 1/R2)/(1/R2) = (R2/R1 + 1) = 3.20 for measurement in units of Celsius (Kelvin) and = 8.11 for Fahrenheit (Rankine).  The “approximately” thing comes in because the resistor ratio needed to be fudged (slightly) to compensate for the few 10s of mV of varying difference between V+ and Q1’s Vbe and thus make the current ratios accurately equal to the calculated values.

The resulting 100uVpp per degree AC signal is synchronously rectified by U1b and filtered by C3 to become the 100uV per degree of absolute temperature DC output signal suitable for direct input to a DMM.  A ~5kHz clock signal for current switching and rectification is provided by U1c, with a little help from one side of U1a.

Note that, per Williams’ analysis of the ΔVbe effect, accuracy of temperature measurement relies only on the accuracy of the current ratio and therefore on only the precision of R1 and R2.  No other reference is required or relevant and any 2N3904 will do. 

The V+ supply, for example, can vary from 3 to 6 volts without affecting accuracy.  Passive output impedance is roughly 10k.  So, loading by a typical 10M DMM input won’t either.

Thanks, Jim!

Stephen Woodward‘s relationship with EDN’s DI column goes back quite a long way. Over 200 submissions have been accepted since his first contribution back in 1974.  They have included best Design Idea of the year in 1974 and 2001.

Related Content 

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• A temperature-compensated, calibration-free anti-log amplifier
• Thermopile sensors: A guide to non-contact temperature measurement

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Here is how design engineers can implement over-the-air (OTA) firmware updates for a microcontroller using the “staging + copy” method. The microcontroller—NXP’s RW612 in this design case study—relies on external serial flash. The article highlights the use of NXP’s ROM-resident FlexSPI API to safely erase and program the flash without bricking the device.

Figure 1 RW612 is a wireless microcontroller with an Arm Cortex-M33 application core. Source: NXP

The OTA process involves downloading the new firmware into a secondary staging partition, verifying, and then copying it to the active partition upon reboot. The article also points to a practical, production-ready example for developers.

For a practical application of OTA implementation, check the complete video tutorial that explains how to implement a remote firmware update. In this video, we use the NXP FRDM-RW612 development board with Mongoose Wizard, but the same method applies to virtually any other NXP microcontroller.

OTA firmware update

If you are looking for a practical OTA firmware update example, this article shows a simple “staging + copy” method on the NXP RW612 microcontroller using external FlexSPI flash. It matches what the FRDM-RW612 board setup looks like in real life, and it points to the exact Mongoose source file (ota_rw612.c) that implements the flow.

Figure 2 The FRDM-RW612 development board is designed for rapid prototyping with the RW61x family of wireless microcontrollers. Source: NXP

OTA firmware updates let you ship fixes and features without asking users to plug in a debugger. On Wi-Fi MCUs, such as NXP RW612, OTA is also one of the first things you want because it unlocks faster iteration during development.

There is no single “correct” OTA design. Different products pick different strategies depending on flash size, how paranoid you are about power loss, and how strict your security requirements are. Here are a few common patterns you will see in the wild:

• In-place update (single slot): Download the new firmware and overwrite the currently running image. This uses the least flash, but it has the highest risk; if power is lost while you erase or program, you may brick the device unless a bootloader can recover.
• Staging + copy: Download the new image into a staging area (an “inactive” region), verify it, and then copy it over the active firmware region. This is a very common and practical method because the device keeps running the old firmware while the download happens, and you only switch after you have a complete, verified image.
• A/B (dual slot): Split flash into two full firmware slots and select which one to boot. It’s viable when you can afford the space, because rollback can be as simple as flipping a flag. It does, however, require enough flash for two complete images plus metadata.
• Delta updates: Download only the binary diff from the old version to the new version and reconstruct on the device. Great for saving bandwidth, but the tooling and edge cases can get complicated fast.

In this article, we focus on the staging + copy approach because it’s easy to reason about, does not require two complete bootable slots, and maps nicely onto RW612 designs with external serial flash.

A minimal staging + copy flow looks like this:

1. Reserve a staging region in external flash plus a tiny metadata area.
2. While running the current firmware, download the new firmware into the staging region.
3. Verify the staged image (signature and/or CRC, size checks, and version rules).
4. Reboot into a small bootloader or early-boot update routine.
5. Copy the staged image over the active firmware region, update metadata, and then boot the new firmware.

Here is a practical note: the easiest way to create a staging area is to split the external flash into two partitions. You keep the active firmware in the first partition and use the second partition as the staging area for the download. After verification, you copy from the second partition back into the active region during reboot.

If power is lost during the download, you still have the old firmware. If power is lost during the final copy, a well-designed bootloader can retry the copy or fall back to a known-good image (depending on your layout and policy). Either way, the goal is the same: avoid bricking devices.

External flash and FlexSPI ROM API

A key RW612 detail that influences OTA design: RW612 does not have built-in internal flash for your application image. Instead, designs typically use external serial NOR flash connected over FlexSPI. The FRDM-RW612 development board, for example, includes external serial flash (Winbond) on the board. That means your OTA code ultimately needs to erase and program external NOR flash.

The nice part is that NXP provides a ROM-resident API that can operate that flash through FlexSPI. In the MCUXpresso SDK documentation, you will see this described as the ROM API driver for external NOR flash connected to the FlexSPI controller, with support for initialize, program, and erase operations.

Why a ROM API matters: when you update flash, you want the programming logic to be as reliable as possible. ROM-resident routines are not stored in external flash, so they can still run safely while you are erasing and programming the external device.

Here are references for RW612 and FlexSPI ROM API (MCUXpresso SDK):

• RW612 datasheet (notes off-chip XIP flash and FlexSPI interface)

https://www.nxp.com/docs/en/data-sheet/RW612.pdf

• FRDM-RW612 board user manual (mentions external serial flash on the board)

https://www.mouser.com/pdfDocs/NXP_FRDM-RW612_UM.pdf

• MCUXpresso SDK ROMAPI driver reference (external NOR over FlexSPI)

https://mcuxpresso.nxp.com/api_doc/dev/2349/a00044.html

• MCUXpresso SDK romapi examples index

https://mcuxpresso.nxp.com/mcuxsdk/25.03.00/html/examples/driver_examples/romapi/index.html

• MCUXpresso SDK romapi_flexspi example readme

https://mcuxpresso.nxp.com/mcuxsdk/25.03.00/html/examples/driver_examples/romapi/flexspi/readme.html

• MCUXpresso SDK fsl_romapi example readme

https://mcuxpresso.nxp.com/mcuxsdk/latest/html/examples/driver_examples/fsl_romapi/readme.html

Practical layout tip for RW612 OTA: treat the external flash as your update playground. Reserve space for the active firmware, a staging region, and a small metadata area that records the update state. Keep the metadata redundant (two copies, versioned records, or a simple log) so you can survive an interrupted write.

Mongoose OTA example

If you want something you can build and run quickly, Mongoose includes a working RW612 OTA implementation that demonstrates the staging + copy method on the FRDM-RW612 board. The walkthrough video is at the beginning of this article and the implementation lives in https://github.com/cesanta/mongoose/blob/master/src/ota_rw612.c.

At high level, the Mongoose RW612 OTA example does three jobs:

1. Receive the new firmware image over the network

The transport can be HTTP, HTTPS, or whatever your product uses. In a typical Mongoose setup, you stream the incoming bytes straight to the staging region in external flash, so you don’t need a giant RAM buffer.

2. Write the new image into the staging region using the FlexSPI ROM API

The OTA code erases the destination region (sector erase) and programs data (page program) as the download progresses. This is the part that is RW612-specific: you use the ROM API FlexSPI routines to safely erase and program the external serial NOR flash.

3. Copy staged firmware to the active region and switch over

After the image is fully written and verified, you reboot. Early in boot, the update routine copies the staged image to the active firmware region using the same FlexSPI ROM API. Finally, metadata is updated, so the device knows the update is complete and the new firmware boots.

Below are a few practical details that are worth copying into your own RW612 OTA design:

• Stream to flash

Do not buffer the whole image in RAM. Erase in sector-sized chunks and program in page-sized chunks as data arrives.

• Verify before you copy

At minimum, store and check a CRC of the downloaded image. For production, verify a signature and enforce anti-rollback rules if needed.

• Make the update state robust

Store update metadata in a small, dedicated region (for example, “no update”, “downloaded”, “copy in progress”, and “done”). Consider writing metadata as an append-only record or keep two copies and alternate between them so you can recover from a power cut during the metadata update.

• Handle power loss during the final copy

A common trick is to mark “copy in progress” before you start copying; then if the device reboots unexpectedly, the boot code can resume the copy from where it left off or restart it safely. Another trick is to copy in fixed chunks and persist progress.

If you just want to see it working, start with the demo video, then open ota_rw612.c and trace the flow: where the image bytes land in external flash (staging), how the ROM API based erase and program calls are made, and how the staged image is copied over the active region during reboot.

That’s how RW612 OTA is done in a way that is simple, resilient, and easy to productize.

Sergey Lyubka is director at Cesanta Software.

Related Content

• OTA Software Updates: Where Are We?
• Memory solutions for firmware OTA updates
• Addressing the challenge of automotive OTA update
• OTA: A Core Technology for Software-Defined Vehicles
• The role of phase-change memory in automotive OTA firmware upgrades

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It seems any expert who can spell “AI” has an opinion on its potential impact. There are countless predictions out there, many made with precision and confidence, and they are often contradictory.

Depending on who you listen to, AI will cause widespread disruption and unemployment, especially at starting and lower middle-levels, open up new vistas and ways of working and getting things done, resulting in the need to hardly do any work, or make us all work harder to stay in place…you get the picture. Whatever answer you want, you can find someone who has provided it.

I’ll jump in and give you my prediction on the impact of AI, with a two-part answer. First, I don’t know, and second, neither does anyone else.

If you look back at the track record of predictions about how past technical advances would unfold, one thing is clear: Most of these prediction underestimate or overestimate the reality, and most of them miss the actual nature of the change that these advances spur.

AI and analog: Round 1

Initially, I thought of doing a “thought experiment” about analog design and AI and go beyond the issues of general analog considerations. But then it made more sense to look at some of the specific stages of analog design, from ICs to circuits and systems, and all the way to final documentation.

However, I realized soon that it was a swamp. There were so many perspectives, so many considerations, and so many exceptions that it would take a lengthy treatise rather than a modest blog to begin to highlight the possibilities. The only meaningful possibility I could think of was using AI to help a beleaguered designer doing “best” component selection.

For example, this might be the task of choosing an op amp that fits the application priorities from among the dozens of vendors and thousands of models. Going further, AI might even help with some trade-off decisions (“show me an op amp that has 10% more dissipation than my stated maximum, if it gives me a 20% improvement in noise”).

AI and analog: Round 2

I then asked myself if it would make sense to instead look at AI and analog from the opposite direction: how can AI help analog-centric systems—meaning those with real-world front-end sensors—do a better job or perhaps implement innovative architectures.

My question was answered when I came across a project from researchers at the University of California, Davis. They used a different approach to miniaturization of a spectrometer that reduced its size to the scale of a grain of sand. This compact spectrometer-on-a-chip is designed for integration into portable devices. Instead of separating light into a spectrum physically, the system relies on computational reconstruction.

Conventional spectrometers rely on dispersive elements such as diffraction gratings or prisms to spatially separate light into its constituent wavelengths. But it requires long path lengths and bulky designs to separate individual wavelengths. The need to spatially disperse the light makes it challenging to miniaturize these delicate and expensive systems, making them unsuitable for portable applications.

On the contrary, the so-called reconstructive spectrometers use a unique set of numerous but compact photoresponsive detectors to directly encode the complex spectral information, which is later extracted using advanced computational algorithms. The team leveraged recent advances in machine learning and computational power, thus enabling further miniaturization toward chip-scale design with reduced manufacturing cost (Figure 1).

Figure 1 Working mechanisms of spectrometers include conventional spectrometers with uniform detector arrays that disperse the light spatially using diffraction gratings, which require long path lengths owing to their bulky nature (a). Then there are reconstructive spectrometers that utilize unique photodetectors capturing the minute variations in the incident light spectrum. The spectral information is then reconstructed using machine learning algorithms (b).

The chip replaces traditional optics with an array comprising 16 silicon detectors, each tuned to respond slightly differently to incoming light. Together, these detectors capture overlapping signals that encode the original spectrum, and they can provide wider bandwidth due to the use of staggered, tailored sensors for each spectrum slice. This process is similar to having multiple sensors that sample different elements of a complex signal, with the full picture emerging only after full analysis.

The analysis is performed using AI where the spectral reconstruction of an unknown spectrum is what has been defined as an inverse problem. The spectral reconstruction of the photon-trapping structures of the spectrometer is performed using a fully connected neural network that solves the inverse problem; an outline of the training and reconstruction process is shown in Figure 2.

Figure 2 Neural network model for spectral reconstruction shows demonstration of the training and reconstruction process of the neural network (a). Training and validation losses plotted against epoch show convergence of the model (b). The model is trained for 2,000 epochs with the loss function converging around 0.03, where comparison of spectral reconstruction uses matrix pseudo-inversion (c), linear combination of Gaussian functions (d), and neural network model (e).

The neural network model outperforms the other two methods in reconstructing the spectral profile of a 3-nm full width at half maximum (FWHM) laser peak. The root-mean-square error (RMSE) and Pearson’s R value (a correlation coefficient) for the neural network model are 0.046 and 0.87, respectively, indicating high accuracy in spectral reconstruction.

The training process involves learning the complex spectral encoding between the photocurrent of photon-trapping structure-enhanced photodetectors and their corresponding spectral information by back-propagating the loss function.

Their detailed modeling, analysis, and experimental results also demonstrated that this approach provided superior noise tolerance compared to traditional spectrometers despite the low photon intensity and small capture area. The fascinating story is presented in a highly readable paper “AI-augmented photon-trapping spectrometer-on-a-chip on silicon platform with extended near-infrared sensitivity” published in Advanced Photonics.

I’ll be honest: When I first saw this paper, my first if somewhat cynical thought was that this was just an attempt to dress up an old analog signal-chain technique with an AI “glow.” There are two basic ways to implement a precision sensor-based path. First, use top-grade components and various circuit topologies such as matched resistors to cancel errors to the extent possible. Second, use lesser components and just calibrate out inaccuracies.

But as I continued to read their paper, I saw that the neural network method added a new level of sophistication and ability to work through inherent weakness in the design and components to deliver an impressive result.

Where do you see AI helping, if at all, in the design cycle of an analog circuit or system? Allowing new topologies for sensor-based systems that were previously not viable or practical.

Related Content

• The Wright Brothers: Test Engineers as Well as Inventors
• Precision metrology redefines analog calibration strategy
• Optical combs yield extreme-accuracy gigahertz RF oscillator
• Achieving analog precision via components and design, or just trim and go

The post What’s the impact of AI on analog design appeared first on EDN.

This design based on an SR latch and two RC networks is, unlike many alternative solutions, neither complex nor expensive.

Single and differential capacitance sensors are widely used to measure linear and angle displacement, pressure, proximity, humidity, fluid level, inclination and acceleration. Both analog and digital circuits are used to interface the sensors (References 1-4). Some of the solutions tend to be complex and expensive (References 5-9).

Wow the engineering world with your unique design: Design Ideas Submission Guide

This Design Idea presents a very simple circuit to interface differential capacitance sensors (Figure 1). It is a relaxation oscillator made of an SR latch and two RC networks. When one of the capacitors is gradually charged through the corresponding resistor, the other capacitor is quickly discharged through a parallel switch. When the charging capacitor reaches the trip voltage VT of its gate, the latch changes its state. The other capacitor starts charging and the first one is quickly discharged. When the second charging capacitor reaches the trip level VT of its gate, the latch flips again returning to the initial state. The charge-discharge process repeats over and over again.

Figure 1 The sensor becomes part of a relaxation oscillator where one of the capacitors is charging when the other one is shorted; the two capacitors periodically swap their operation.

Signal VQ1 goes to a microcontroller, which measures time intervals t1 and t2 and calculates the average value VAVR = VDD * t1 / (t1 + t2). A number needs to be subtracted from this value so when the two capacitors are equal the average value is zero. Thus, the average value will be positive when C1 > C2 and negative when C1 < C2.

Circuit operation was tested with a bank of ten 50-pF capacitors. The left side of Figure 2 shows connections to set a duty cycle of 20%; the right side of the figure sets the duty cycle of 90%.

Figure 2 Sensor operation is simulated with a bank of 10 capacitors.

Figure 3 presents how period T and duty cycle D = t1 / T depend on the value of C1. Period barely changes between 96 and 98 µs, while the duty cycle is proportional to C1. A straight line fits perfectly the duty cycle data (the R2 factor equals 1); however, as Figure 4 shows, the line has a nonlinearity error of ±0.3%.

Figure 3 Circuit responses: at the top, the period is almost the same, below it, the duty cycle depends linearly on the value of C1.

Figure 4 The duty cycle response has a nonlinearity error of ±0.3 %.

The bump shape of the error graph means that a second-order polynomial may improve linearity. Indeed, equation y = 1*10-5 * x2 + 0.182 * x + 4.21 reduces the error down to ±0.1%. Such an equation is easy to implement in the microcontroller firmware.

Jordan Dimitrov is an electrical engineer & PhD with 40 years of experience. Currently, he teaches electrical and electronics courses at a Toronto community college.

Related Content

• From gap to signal: Non-contact capacitive displacement sensors
• Fundamentals in motion: Accelerometers demystified
• An introduction to capacitive sensing

References

1. Regtien P., E. Dertien. Sensors for mechatronics. 2nd ed., Ch. 5, Elsevier, 2018.
2. Northrop R. B. Introduction to instrumentation and measurement. 3rd ed., CRC Press, 2014.
3. Baxter L. Capacitive sensors. http://www.capsense.com/capsense-wp.pdf
4. Differential capacitance pressure sensor circuit. https://instrumentationtools.com/differential-capacitance-pressure-sensor-circuit/
5. Reverter F., O. Casas. Direct interface circuit for differential capacitive sensors. I2MTC 2008 – IEEE International Instrumentation and Measurement Technology Conference, Victoria, Vancouver Island, Canada, May 12-15, 2008.
6. Barile G. et al. Linear integrated interface for automatic differential capacitive sensing. Proceedings 2017, 1, 592.
7. Ferri G. et al. Automatic bridge-based interface for differential capacitive full sensing. 30th Eurosensors Conference, EUROSENSORS 2016. Procedia Engineering 168 (2016) 1585 – 1588.
8. Bai Y. et al. Absolute position sensing based on a robust differential capacitive sensor with a grounded shield window. Sensors (Basel). 2016 May; 16(5): 680. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4883371/
9. De Marcellis A., C. Reig, M. Cubells-Beltrán. A capacitance-to-time converter-based electronic interface for differential capacitive sensors. MDPI Electronics, Jan 2019.

The post Simple circuit interfaces differential capacitance sensor appeared first on EDN.

Three smart home hubs, from two different companies. All supporting both 2.4 GHz Wi-Fi and proprietary 900 MHz wireless links. How do they differ, and are similar? Let’s find out.

Last month, I told you about TP-Link’s Tapo Hubs and their functional similarity to Blink’s Sync Modules. And last week, I took apart Blink’s second-generation hub, comparing it to its premiere predecessor which’d gone “under the knife” nearly a decade earlier. Today, I’ll be dissecting the entry-level Tapo H100 hub I conceptually covered in late March.

How comparable (or not) is its design to those of its Blink competitors? Let’s dive in and see.

Smart hub brothers from different mothers?

I shared a full set of outer box shots last month; so to avoid redundancy, this time I’ll show only the perspective that’s different, since last month’s device remains in ongoing use while this one (with a different serial number) is intended (initially, at least) solely for dissection.

As usual, it’s accompanied by a 0.75″ (19.1 mm) diameter U.S. penny for size comparison purposes. Also note that, per the common “US/1.26” notation on the sticker found on the bottom of both boxes, this device and last month’s H100 are presumably based on the same hardware version.

Opening up the packaging, you’ll find a sliver of literature inside, with our patient below it.

The only constant is change

On the product support page I initially referenced earlier, you’ll also discover that there have been four hardware versions to date: v1.0, v1.2, my v1.26, and the subsequent (I’m assuming) v1.8. Attempts to mix-and-match divergent hardware, as I’ve noted before, can be problematic. That said, most households will contain only a single hub device (versus multiple sensors and other “smart” peripherals), minimizing the potential-problem set size in this particular case.

Before continuing, let’s revisit the backside of the device, this time zooming on the markings.

Notice what looks like a label stuck on top of part of the original info? That’s exactly what it is.

As it turns out, the FCC ID found on the backside markings (2AXJ4H100) was also later updated; it’s now 2BH7FH100. Are the two changes related? Dunno.

Time to dive inside, a task that, compared to TP-Link smart switches of (recent) past, was thankfully fairly straightforward this time around.

Inside the front half of the enclosure, you’ll find a speaker (used, for example, to implement the sound emitted when the hub is paired with, and activated by, a “smart” doorbell).

And the mechanical assembly for the pairing-and-reset switch is shown on one side, as seen earlier.

Categorizing the guts

Here, however, is the view that most of you are most interested in, I guess.

The bottom half of the PCB disconnected itself from the back half of the enclosure while I was prying apart the two halves.

Further bending back the PCB reveals how the AC “prongs” connect to it.

As well as the PCB backside itself.

The small five-lead IC in the middle, PCB-labeled U4, is marked:

TACeY1

Its identity is unknown to me (readers?). Below it, in a larger seven-lead package, is On-Bright Electronics’ OB2512NJP offline primary-side-regulation (PSR) power switch. Below that is a M7 high voltage rectifier diode. And to its left is another (bridge and three-lead, this time) rectifier, Galaxy Microelectronics’ MBF10M.

Back to the PCB front side, after “un-popping” the PCB (putting it back in its normal place within the enclosure, which is upside down in both the prior-version and the following photo versus its normal orientation).

Note first the two antennae, one embedded and along the lower edge, the other discrete and along the right side. I assume one’s for 2.4 GHz Wi-Fi while the other supports TP-Link’s proprietary 900 MHz ISM band “ultra-low power wireless protocol”. Reader suggestions as to which is what are greatly appreciated in the comments.

In the upper right (again, lower left in normal operating orientation) is the status LED, which ends up shining out the device front cover. The pairing-and-reset switch is along the left side. The top half of the PCB, perhaps obviously given the sizeable transformer, houses the AC/DC conversion circuitry (the fact that the AC prongs are directly behind it at the rear of the device is another functional tipoff).

And, last but not least, the various ICs. In the lower right corner of the transformer is an Eon Silicon Solution EN56Q64-104HIP 64 Mbit serial flash memory, which we’ve seen before in both higher and lower capacities. I assume it houses the code for Realtek’s RTL8710CM SoC below and to its left, also found in the first two of the three TP-Link smart switches I’ve dissected so far. At the bottom, in the middle, is WayTronic’s WT588F02B audio DSP with an integrated DAC, which “can directly drive 8R 0.5W speakers”, an unsurprising function given the speaker connection directly to the left of it. Above and to the right of the audio DSP is another IC I can’t ID:

35UT
53C1

And above and to the left of the mono speaker connector is one final mystery:

300A
S992
515

Reader insights into any of the chips I was unable to identify, as well as broader thoughts on anything I’ve discussed here, are always welcome in the comments.

Brian Dipert is the associate editor, as well as a contributing editor, at EDN.

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The post TP-Link’s Tapo H100: Smart sensing unencumbered appeared first on EDN.

Ketone detection may sound like the domain of biochemistry, but at its core, it’s also an electronics challenge: how do we translate a chemical presence into a measurable electrical signal?

The key lies in the ability of circuits to convert molecular interactions into quantifiable outputs. Through principles like signal conversion, amplification, and conditioning, electronics transform invisible chemical activity into reliable data, making ketone monitoring practical and accurate while underscoring how deeply electronics shape modern health technologies.

Ketones: Small molecules, big impact

Ketone detection is crucial because these molecules act as direct indicators of how the body manages its energy balance. Moderate levels can reflect healthy states such as fasting, exercise, or adherence to ketogenic diets, while dangerously high concentrations may signal conditions like diabetic ketoacidosis that require urgent medical attention.

By providing timely and accurate measurements, ketone monitoring empowers individuals to optimize nutrition and performance and gives clinicians essential data to prevent and manage metabolic complications. In both everyday wellness and clinical care, reliable ketone tracking plays a decisive role in safeguarding health.

Overview of ketone detection sensors

Nowadays ketone detection has moved well beyond the lab bench and into lifestyle and wearable electronics. Compact analyzers are being built into fitness trackers, smartwatches, and portable health devices, giving users real-time insights into metabolism and diet. This evolution is powered by the fundamentals of electronics—miniaturization, low-power design, and signal processing—that make complex biochemical measurements practical in everyday life, turning health monitoring into a seamless part of daily routines.

While electronics provide the backbone for translating chemistry into measurable signals, the choice of sensor defines how ketones are detected. Electrochemical sensors generate currents via redox reactions, optical sensors capture variations in light absorption or fluorescence, and chemiresistive sensors—including semiconductor gas sensors—exploit surface-level conductivity shifts. Each technology offers a unique pathway from molecular interaction to electrical output, setting the stage for circuits to amplify, filter, and interpret the data with precision.

Ketone sensing: The gold standard and beyond

In practice, blood testing is the clinical gold standard, using the enzyme β-hydroxybutyrate dehydrogenase (HBDH) to generate a precise electrical signal from β-hydroxybutyrate (BHB). Keep note that a blood ketone meter functions as a miniaturized potentiostat; it maintains a fixed voltage across the biosensor to measure the current produced by this reaction, providing the data needed to distinguish safe ketosis from metabolic crisis.

Figure 1 Today’s multifunction blood meter kits provide a fast and reliable method for measuring β-ketone, blood glucose, and other parameters from fresh whole blood samples in just a few simple steps. Source: eLinkCare

However, the field is evolving beyond the invasive finger-prick. Researchers are now optimizing alternative biomarkers and delivery methods to bridge the gap between clinical accuracy and user convenience.

Exhaled breath analysis targets acetone—a volatile byproduct of fat metabolism. Current technologies, such as chemiresistive metal-oxide sensors, offer a high-frequency, non-invasive “proxy” for ketosis. While breath analysis currently lacks the clinical precision required for acute emergencies like diabetic ketoacidosis (DKA), it provides a sustainable, pain-free alternative for routine wellness tracking.

In a nutshell, ketone breath analyzers typically employ semiconductor-based, chemiresistive sensors to detect acetone—a byproduct of fat metabolism—in exhaled breath. These sensors function by measuring changes in electrical resistance triggered by volatile organic compounds (VOCs), which serves as a proxy for blood ketone concentration. High-end models often integrate CMOS technology to enhance both sensitivity and measurement precision.

Figure 2 Ketone breath analyzers and subcutaneous sensors deliver real-time feedback on ketosis levels. Source: Author

Continuous ketone monitoring (CKM) is an emerging technology that utilizes a small subcutaneous sensor—similar to a continuous glucose monitor (CGM)—to measure BHB levels in the interstitial fluid. By providing real-time data and automated alerts, these devices aim to detect rising ketone levels before they escalate into metabolic emergencies, effectively transitioning patient care from ‘spot-check’ diagnostics to continuous, proactive health management.

Note that a subcutaneous sensor is a tiny, flexible filament inserted into the fatty tissue just beneath the skin. By monitoring the interstitial fluid in this layer, the sensor uses enzymes to measure specific chemical markers—like glucose or ketones—and converts those readings into a continuous digital stream. Because it stays in place for several days and does not require venous access, it offers a painless, real-time alternative to repeated finger-prick testing.

Electronic biosensing for makers

To wrap this up, remember that while the medical industry uses highly proprietary, pre-calibrated systems, the underlying principle is a fantastic playground for makers.

Whether you are working with a glucose oxidase strip for blood sugar or a β-hydroxybutyrate strip for ketone levels, the principle is the same: enzyme-mediated reactions generate electrons that must be measured against a stable reference potential.

Once you master the transimpedance amplifier (TIA), you have essentially built the core of a professional-grade diagnostic instrument. In fact, most commercial biosensors integrate the TIA and supporting circuitry into an analog front end (AFE), which delivers low-noise performance and simplifies design, an approach that makers can emulate at smaller scale when experimenting.

On a related note, amperometry is the electrochemical technique at the heart of most biosensor strips. It involves applying a fixed potential to an electrode and measuring the resulting current, which is directly proportional to the concentration of the analyte.

In glucose oxidase strips, the enzymatic reaction produces hydrogen peroxide that is oxidized at the electrode, while in β-hydroxybutyrate strips, NADH transfers electrons through a mediator. In both cases, the transimpedance amplifier converts this tiny current into a usable voltage signal, enabling accurate, low-noise measurement.

Figure 3 Quick view shows a closeup of a standard ketone blood tester strip. Source: Author

For those curious about non-chemical ketone monitoring, it’s worth noting that hobbyists have also experimented with MQ13x series gas sensors such as MQ138 to approximate acetone levels in breath.

These gas sensors are not medical-grade and require careful calibration against known standards, but they can respond to volatile organic compounds in exhaled breath. Pairing one with a microcontroller, a stable heater supply and signal conditioning circuitry give you a rough, experimental ketone breath analyzer. It’s a fun proof-of-concept project—ideal for learning sensor physics and electronics.

Figure 4 MQ138 sensor module helps detect acetone in exhaled breath, enabling experimental DIY ketone analysis. Source: Author

Just keep in mind that for any real-world health tracking, these DIY setups should be for educational exploration only. Medical-grade devices undergo extensive clinical validation to handle variables like hematocrit levels, temperature, and signal interference—factors that a prototype might miss.

Finally, do not let the complexity of biomedical electronics intimidate you. Every expert once started as a novice tinkering with circuits and sensors. Dive in, experiment boldly, and let curiosity be your guide—the frontier of electronic biosensing is wide open for makers willing to explore.

T. K. Hareendran is a self-taught electronics enthusiast with a strong passion for innovative circuit design and hands-on technology. He develops both experimental and practical electronic projects, documenting and sharing his work to support fellow tinkerers and learners. Beyond the workbench, he dedicates time to technical writing and hardware evaluations to contribute meaningfully to the maker community.

Related Content

• What’s in store for optical biosensors?
• The critical role of sensors in medical devices
• Designer’s guide: Sensors for medical applications
• Developing medical sensors compliant with global requirements
• Tools and techniques for electrical characterization of biosensors

The post Electronic biosensing: A quick take on ketone detection appeared first on EDN.