Isolated Sigma-Delta Modulators, Rah Rah Rah!
Analog isolation can blow up DAQ budgets, but isolated sigma-delta modulators let you send a single 1-bit stream and a clock across the barrier, keeping costs down. Jason walks through Avago, TI, and Analog Devices parts, explains sigma-delta noise shaping in plain terms, and calls out the real engineering work: converting a 10–20 MHz bitstream into usable samples with sinc/CIC decimators or FPGA filtering.
Oscilloscope review: Hameg HMO2024
Jason Sachs tests the Hameg HMO2024, a 200MHz 4-channel mixed-signal oscilloscope that promises Agilent-like features at a lower price. He finds strong analog noise performance, useful hi-res and zoom modes, and inexpensive serial-decode options, but warns of clumsy digital-input handling, awkward data-transfer software, and missing per-channel thresholds and Ethernet waveform export. The review helps budget-conscious embedded engineers weigh the trade-offs.
Two jobs
Stephane Boucher explains why EmbeddedRelated went quiet for a few months after a volunteer project demanded more of his time. He and his wife organized a clown-gymnastics show with 15 kids, sold more than 700 of 800 tickets, and raised $2,700 for the Tree of Hope. Now the shows are done and he plans to resume regular posting with new site features.
Have You Ever Seen an Ideal Op-Amp?
Forget the ideal op-amp fantasy, Jason Sachs walks through the practical nonidealities that make textbook gain formulas fail in real circuits. Using the uA741C and TLC081C as examples, he explains offset voltage, input bias and offset currents, common-mode and supply rejection, gain-bandwidth and slew-rate limits, plus capacitive loading, RF rectification and overload recovery. Read to learn which datasheet specs matter and why.
Hot Fun in the Silicon: Thermal Testing with Power Semiconductors
Bringing hundreds of amps into the lab for low-Rds(on) MOSFET thermal tests is impractical. Jason Sachs demonstrates a clever workaround using a zener diode, a series resistor, and a constant-current lab supply to dump the same watts into the device at much lower current. He also explains how to use datasheet RθJC values and type T thermocouples to estimate junction temperature and size heatsinking or airflow.
10 More (Obscure) Circuit Components You Should Know
Jason Sachs follows up his earlier primer with ten more underused but practical parts that can simplify embedded hardware designs. From MOSFET-based ideal diode controllers that eliminate diode drops to TAOS light-to-frequency sensors that expand dynamic range, the post explains what each component does, when to choose it, and real-world tradeoffs learned from field use. Ideal for engineers looking to broaden their parts toolbox.
Oscilloscope Dreams
Jason Sachs walks through practical oscilloscope buying criteria for embedded engineers, focusing on bandwidth, channel count, hi-res acquisition, and probing. He explains why mixed-signal scopes and hi-res mode matter, when a 100 MHz scope is sufficient and when to keep a higher-bandwidth instrument, and how probe grounding and waveform export can ruin measurements. Real-world brand notes and try-before-you-buy advice round out the guidance.
Stairway to Thévenin
Jason Sachs strips away classroom mystique to show how Thevenin and Norton equivalents are practical tools for real embedded work. Using a simple two-terminal black-box example he shows how two measurements give Vth and Rth, then applies that model to voltage-divider references, potentiometer RC filters, and combining multiple sources with Millman's theorem. Read it for fast, practical ways to predict output impedance, droop, and filter time constants.
10 Circuit Components You Should Know
Jason Sachs pulls together ten underrated but highly practical circuit components that every embedded engineer should know. From multifunction logic gates that act like a Swiss Army knife for glue logic to TL431 shunt regulators and tiny charge-pump inverters, each item is presented with real-world use cases and caveats. Read this to expand your parts toolbox and simplify future designs.
Analog-to-Digital Confusion: Pitfalls of Driving an ADC
Wayne's thermistor board showed one ADC channel changing when another was heated, a classic case of ADC input cross-coupling. The post walks through how multiplexed ADCs, the small sample-and-hold capacitor, source impedance, sampling time, repeated sampling rates, and added charge reservoirs interact to create errors. Learn practical fixes including increasing sample time, sizing external caps, adding op-amp buffers, and using an RC dampener with PCB layout tips.
Short Takes (EE Shanty): What shall we do with a zero-ohm resistor?
When you need flexibility on a PCB, zero-ohm resistors are the obvious shortcut, but Jason M. Sachs shows why the label zero is misleading. He compares common SMT jumper specs, high-current specialty parts, and a practical workaround using 1 milliohm resistors to avoid voltage drop. Read this for a quick checklist to pick jumpers that actually carry your board's current.
Stability or insanity
Tim Wescott presents a hands-on exploration of oscillator stability using a custom electromechanical pendulum. He converts a hard‑drive head actuator into a pendulum resonator, winds a 220‑ft #40 coil, and mounts the assembly on low‑friction ball bearings before integrating it into an electronic oscillator. Iteration and careful modeling—treating the pendulum as a resonator and including coil inductance in the circuit—prove essential to obtain sustained oscillation. The resulting prototype functions as an intentionally inaccurate electro‑mechanical clock driven by a "tick‑toc" circuit that minimizes load to preserve a high loaded Q and requires manual start to demonstrate a hard limit cycle. The project highlights practical tradeoffs between stability, Q, and the realities of prototyping.
Another 10 Circuit Components You Should Know
Jason Sachs walks through ten underrated circuit components every embedded engineer should know, from bus switches and thermocouple signal ICs to PCB stiffeners and opto-FET isolators. He mixes practical part examples, high-current hardware tips, and MCU features like CTMU and Peripheral Pin Select so you can pick the right trick when space, isolation, or precision matter.
Efficiency Through the Looking-Glass
Efficiency numbers can be misleading, Jason Sachs argues, because they hide the real cost engineers pay in wasted watts. This post flips the focus from percent efficiency to absolute power loss, shows how losses often stay nearly constant across loads, and walks through a practical thermal method to measure those losses more reliably than subtracting input and output power. Read it to rethink how you budget heat and energy in designs.
10 Items of Test Equipment You Should Know
Jason Sachs walks through ten often-overlooked pieces of test gear that make debugging embedded hardware faster, safer, and more precise. From clamp-on and Rogowski current probes to spring-tip probes, IC test clips, and compact DAQ systems, each tool targets a common bench frustration. Practical buying notes and use cases help you choose tools that save time and reduce guesswork.
March is Oscilloscope Month — and at Tim Scale!
Jason Sachs just upgraded his lab with an Agilent MSOX3034A after snagging a vendor promotion, and he walks through first-day wins from probe compensation to scripting. He shows why 10x probes need capacitive matching and how to use the scope's calibration square wave to compensate them. He also covers connecting the MSOX3000 to Python via pyvisa and SCPI, including decoding waveform data for export.
What IS an electron?
The post surveys historical and theoretical perspectives to ask what an electron actually is, treating the electron as a working scientific model rather than an absolute object. It traces the concept from early electrical technology and J.J. Thomson’s discovery through Maxwell’s relativistic field laws and Dirac’s relativistic quantum equation, noting spin, positrons, and radiation puzzles that led to quantum mechanics. The article discusses collective behaviors — Langmuir’s paradox, exchange-correlation in plasmas, density functional theory in solids, and superconducting pairing — and emphasizes that an electron can appear pointlike at high energies, wave-like in atoms, and collective in materials, so the practical answer depends on experimental context and timescale.
Complexity in Consumer Electronics Considered Harmful
Jason Sachs watched his grandmother struggle with a Vizio TV remote, and it highlights a recurring usability failure in consumer electronics. He argues that small type, unclear icons, and modal controls make everyday tasks needlessly hard. The takeaway for embedded engineers is to prioritize common actions, separate advanced features, and design for low-vision and limited-memory users to avoid frustration and returns.
Hot Fun in the Silicon: Thermal Testing with Power Semiconductors
Bringing hundreds of amps into the lab for low-Rds(on) MOSFET thermal tests is impractical. Jason Sachs demonstrates a clever workaround using a zener diode, a series resistor, and a constant-current lab supply to dump the same watts into the device at much lower current. He also explains how to use datasheet RθJC values and type T thermocouples to estimate junction temperature and size heatsinking or airflow.
What is Electronics
This article challenges the conventional circuit-theory view and defines electronics as the controlled flow of electromagnetic field energy in conducting structures. It argues that signals are manifestations of stored and moving energy in the space between conductors rather than energy residing primarily inside conductors, using transmission-line examples to illustrate how only a tiny fraction of electrons carry current while most energy occupies surrounding fields. The post contrasts Maxwell’s field-based perspective with lumped-circuit abstractions, explains wavefronts, reflections, and the exchange between electric and magnetic energy, and shows how those behaviors produce oscillation and signal issues. The practical conclusion is that PCB geometry, impedance control, and decoupling placement must be designed to provide smooth paths for field energy to minimize interference and support high-speed operation.
Feedback Controllers - Making Hardware with Firmware. Part 4. Engineering of Evaluation Hardware
Following on from the previous abstract descriptions of an arbitrary circuit emulation application for low-latency feedback controllers, we now come to some aspects in the hardware engineering of an evaluation design from concept to first power-up. In due course a complete specification along with application examples will be maintained on the project website.
- Part 1: Introduction
- Part 2:...
Feedback Controllers - Making Hardware with Firmware. Part 9. Closing the low-latency loop
This article demonstrates combining DSP and feedback-control on an Intel Cyclone floating-point FPGA to build low-latency closed-loop circuit emulators and controllers. Using a single floating-point biquad at 1.6 Msps, an IFFT multi-tone 4.096 ms capture for wideband measurement, and MATLAB references for verification, the author achieves sub-nanosecond timing insight and applies DSP phase compensation to cancel about 100 pF of PCB parasitics.
Stability or insanity
Tim Wescott presents a hands-on exploration of oscillator stability using a custom electromechanical pendulum. He converts a hard‑drive head actuator into a pendulum resonator, winds a 220‑ft #40 coil, and mounts the assembly on low‑friction ball bearings before integrating it into an electronic oscillator. Iteration and careful modeling—treating the pendulum as a resonator and including coil inductance in the circuit—prove essential to obtain sustained oscillation. The resulting prototype functions as an intentionally inaccurate electro‑mechanical clock driven by a "tick‑toc" circuit that minimizes load to preserve a high loaded Q and requires manual start to demonstrate a hard limit cycle. The project highlights practical tradeoffs between stability, Q, and the realities of prototyping.
Helping New Bloggers to Break the Ice: A New Ipad Pro for the Author with the Best Article!
Breaking the ice can be tough. Over the years, many individuals have asked to be given access to the blogging interface only to never post an article.
Hot Fun in the Silicon: Thermal Testing with Power Semiconductors
Bringing hundreds of amps into the lab for low-Rds(on) MOSFET thermal tests is impractical. Jason Sachs demonstrates a clever workaround using a zener diode, a series resistor, and a constant-current lab supply to dump the same watts into the device at much lower current. He also explains how to use datasheet RθJC values and type T thermocouples to estimate junction temperature and size heatsinking or airflow.
What is Electronics
This article challenges the conventional circuit-theory view and defines electronics as the controlled flow of electromagnetic field energy in conducting structures. It argues that signals are manifestations of stored and moving energy in the space between conductors rather than energy residing primarily inside conductors, using transmission-line examples to illustrate how only a tiny fraction of electrons carry current while most energy occupies surrounding fields. The post contrasts Maxwell’s field-based perspective with lumped-circuit abstractions, explains wavefronts, reflections, and the exchange between electric and magnetic energy, and shows how those behaviors produce oscillation and signal issues. The practical conclusion is that PCB geometry, impedance control, and decoupling placement must be designed to provide smooth paths for field energy to minimize interference and support high-speed operation.
Feedback Controllers - Making Hardware with Firmware. Part 5. Some FPGA Aspects.
This installment digs into practical FPGA choices and board-level issues for a low-latency, floating-point feedback controller. It compares a Cyclone V implementation against an older SHARC-based design, quantifies the tradeoff between raw DSP resources and cycle latency, and calls out Gotchas found on the BeMicro CV A9 evaluation card. Engineers get concrete prompts for where to optimize: clocking, DSP-block use, I/O standards, and algorithm partitioning.
Feedback Controllers - Making Hardware with Firmware. Part 8. Control Loop Test-bed
Built around modest FPGA hardware, this post presents a practical test-bed for evaluating high-speed, low-latency feedback controllers. It covers ADC/DAC specifications, basic and arbitrary test signals, and an IFFT-based generator that can produce thousands of simultaneous tones for rapid Bode, phase, and latency measurements. The article also compares two IFFT strategies, explains turbo sampling, and shows open- and closed-loop test configurations.
Efficiency Through the Looking-Glass
Efficiency numbers can be misleading, Jason Sachs argues, because they hide the real cost engineers pay in wasted watts. This post flips the focus from percent efficiency to absolute power loss, shows how losses often stay nearly constant across loads, and walks through a practical thermal method to measure those losses more reliably than subtracting input and output power. Read it to rethink how you budget heat and energy in designs.
The New Forum is LIVE!
After months of hard word, I am very excited to introduce to you the new forum interface.
Here are the key features:
1- Easily add images to a post by drag & dropping the images in the editor
2- Easily attach files to a post by drag & dropping the files in the editor
3- Add latex equations to a post and they will be rendered with Mathjax (tutorial)
4- Add a code snippet and surround the code with
