Delta Sigma AD Converters
It’s not surprising that Analog to Digital Converters (ADC’s) now employ several techniques to accomplish higher speeds and resolutions than their simpler counterparts. Enter the Delta-Sigma (Δ∑) ADC which combines a couple of techniques including oversampling, noise shaping and digital filtering. That’s not to say that you need several chips to accomplish this, these days
Continue reading »PUTTING HIGH SPEED PCB DESIGN TO THE TEST
Designing circuit boards for high speed applications requires special considerations. This you already know, but what exactly do you need to do differently from common board layout? Building on where I left off discussing impedance in 2 layer Printed Circuit Board (PCB) designs, I wanted to start talking about high speed design techniques as they relate
Continue reading »New Summing Amplifier w/ Coax Driver
AD812 FEATURES Two Video Amplifiers in One 8-Lead SOIC Package Optimized for Driving Cables in Video Systems Excellent Video Specifications (RL = 150 V): Gain Flatness 0.1 dB to 40 MHz 0.02% Differential Gain Error 0.028 Differential Phase Error 145 MHz Unity Gain Bandwidth (3 dB) 1600 V/ms Slew Rate AD812 APPLICATIONS Video Line Driver
Continue reading »New Thermocouple Amplifier with NEMA Housing
The new Thermocouple Amplifier feature two Analog Outputs: 10mv/C° and 4-20ma current loop output, in a NEMA rated housing. This is a Thermocouple Amplifier System Based on Linear Technology’s LT1025 – Micropower Thermocouple Cold Junction Compensator combined with the LTC1049 – Low Power Zero-Drift Operational Amplifier with Internal Capacitors this small circuit provides a basic
Continue reading »COMPLEX PROGRAMMABLE LOGIC DEVICE (CPLD) MODULE
A Complex Programmable Logic Device (CPLD) is a cool piece of hardware to have in your repertoire and it can be used to learn logic or a high level design language or replace obsolete functions or chips. But a CPLD needs a little bit of support infrastructure to become usable, and that’s what I’ll be
Continue reading »WE ASSUME CONTROL: SPI AND A DIGITAL POTENTIOMETER
In the last video I demonstrated a Universal Active Filter that I could adjust with a dual-gang potentiometer, here I replace the potentiometer with a processor controlled solid-state potentiometer. For those that are too young to remember, we used to say “solid-state” to differentiate between that and something that used vacuum tubes… mostly we meant
Continue reading »HOW TO BUILD A THERMOCOUPLE AMPLIFIER
A Thermocouple is a terrific way to measure temperature. The effects of temperature change on dissimilar metals produces a measurable voltage. But to make that measurement you need an amplifier circuit designed for the thermocouple being used. Linear Technology LTC 1049 Low Power Zero-Drift Operational Amplifier with Internal Capacitors While researching “Zero Drift Amplifiers” as
Continue reading »DIRECT DIGITAL SYNTHESIS (DDS) EXPLAINED BY [BIL HERD]
One of the acronyms you may hear thrown around is DDS which stands for Direct Digital Synthesis. DDS can be as simple as taking a digital value — a collection of ones and zeroes — and processing it through a Digital to Analog Converter (DAC) circuit. For example, if the digital source is the output
Continue reading »BIL HERD: COMPUTING WITH ANALOG
When I was young the first “computer” I ever owned was an analog computer built from a kit. It had a sloped plastic case which had three knobs with large numerical scales around them and a small center-null meter. To operate it I would dial in two numbers as indicated by the scales and then
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