Simple GPS Disciplined 10MHz Reference uses Dual PWMs

I was recently working on an experiment for a new design and was using a function generator. Although new function generators have pretty good frequency tolerance specs, I needed something with more accuracy and precision. The way to get more accuracy in frequency generators, arbitrary waveform generators, and frequency counters is to use the 10 … Read more

Using the BlasterAmp – down a rabbit hole of specifications

The BlasterAmp [1] has proven useful to me in testing all sorts of analog-to-digital converter (ADC) circuits, even my digital oscilloscopes. While I mainly conceived it to test integrated ADCs in microprocessors, it can be used to test even RF ADCs. Yes, even that several hundred MHz downsampling ADC can be tested with an audio … Read more

How to Analyze Control Loop Stability with Bode Plots Using Modern Oscilloscopes

This article presents important topics to consider in order to make accurate Bode plots for control loops in switched mode power supplies. Traditionally, the method of choice has been to observe the step response and judge from the timing of whether the control loop is stable and fast enough. However, judging the level of stability … Read more

Snubber Network Choices, Design and Evaluation

Power conversion circuits use snubber networks extensively to control voltage overshoots, improve efficiency and minimize EMI. This article discusses some circuit options and the design basics. Measurement of snubber performance is also discussed, with examples of pitfalls and best techniques for accurate results. Power electronics has a variety of antiquated terms, some dating back centuries … Read more

Mixed Signal Oscilloscope easily goes from bench to field

The 2 Series mixed signal oscilloscope (MSO) from Tektronix provides benchtop performance, yet is small enough to fit in a backpack. Weighing less than 4 pounds, the tablet-like oscilloscope is just 1.5 in. thick and has a 10.1-in. TFT display with a capacitive touchscreen. An optional battery pack supplies up to eight hours of power … Read more

Not your father’s power tools

Project engineer Jason Leh performs voltage, current, temperature, and other measurements to test motor controls.Photo by Joshua Roberts/Getty Images Towson, MD —DeWalt power tools such as drills, saws, and grinders help contractors worldwide build just about anything. Not long ago, power tools were electrically simple—a variable-speed power switch provided power to a motor. Today, electronics … Read more

Stick to the schematic

I recently needed to re-create a settling-time-measurement jig I built 25 years ago. It transmits and receives 10V swings and is flat enough and magnifies enough to see 0.01%/division within 35 nsec on an oscilloscope. You can’t buy such a step generator, and you can’t use an oscilloscope unassisted to see 0.01% absolute-settling features. I … Read more

Eye diagram basics: Reading and applying eye diagrams

Accelerating data rates, greater design complexity, standards requirements, and shorter cycle times put greater demand on design engineers to debug complex signal integrity issues as early as possible. Because today’s serial data links operate at gigahertz transmission frequencies, a host of variables can affect the integrity of signals, including transmission-line effects, impedance mismatches, signal routing, … Read more

Projecting the light

In the reliabiliy lab at Luminus Devices, reliability manager Scot Solimine (left) runs accelerated life tests on the company’s LEDs. Staff engineer Mike Brown analyzes any failure modes and suggests corrective actions. Photo by Adrien Bisson. Read more about LED test.See the rest of our September 2010 issue. Billerica, MA—When lighting designer Kevin Adams designed … Read more