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    • New Summing Amplifier w/ Coax Driver

      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 DriverRead More »
    • New Thermocouple Amplifier with NEMA Housing

      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 basicRead More »
    • COMPLEX PROGRAMMABLE LOGIC DEVICE (CPLD) MODULE

      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 beRead More »
    • WE ASSUME CONTROL: SPI AND A DIGITAL POTENTIOMETER

      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 meantRead More »
    • HOW TO BUILD A THERMOCOUPLE AMPLIFIER

      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” asRead More »
    • DIRECT DIGITAL SYNTHESIS (DDS) EXPLAINED BY [BIL HERD]

      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 outputRead More »
    • BIL HERD: COMPUTING WITH ANALOG

      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 thenRead More »
    • INTERACTIVE SOFTWARE TO SOLVE CROSSTALK PROBLEMS

      INTERACTIVE SOFTWARE TO SOLVE CROSSTALK PROBLEMS

      A link to this video demonstrating PCB cross-talk ended up in my mailbox the other day as I tend to stay on the mailing lists of the some of the high end CAD companies. There are some really interesting and powerful “mega-tools” that do things like plot noise density for decoupling analysis and extremely highRead More »
    • HOW CMOS WORKS: MOSFETS, JFETS, IGFETS AND MORE

      HOW CMOS WORKS: MOSFETS, JFETS, IGFETS AND MORE

      CMOS opened the door for many if not most of the properties needed for today’s highly integrated circuits and low power portable and mobile devices. This really couldn’t happen until the speeds and current drive capabilities of CMOS caught up to the other technologies, but catch up they did. Nowadays CMOS Small Scale Integration (SSI)Read More »
    • COMMVEX 2015: WHAT HAPPENS WHEN COMMODORE USERS GATHER

      COMMVEX 2015: WHAT HAPPENS WHEN COMMODORE USERS GATHER

      I’m not getting any younger, in fact I’m getting older by the day.  This fact along with the fact that this year is the 30th anniversary of the Commodore C-128 and the original Commodore Amiga prompted me to attend this year’s CommVEx in Las Vegas lest I not be around for the next significant anniversary.Read More »
    • GATES TO FPGAS: TTL ELECTRICAL PROPERTIES

      GATES TO FPGAS: TTL ELECTRICAL PROPERTIES

      On the path to exploring complex logic, let’s discuss the electrical properties that digital logic signals are comprised of. While there are many types of digital signals, here we are talking about the more common voltage based single-ended signals and not the dual-conductor based differential signals. Single-ended Logic Signal I think of most logic as being inRead More »
    • MAKING THE CES SHOW… THIRTY YEARS AGO

      MAKING THE CES SHOW… THIRTY YEARS AGO

        This year’s CES has dredged up some memories. I had assumed that as one becomes old they are supposed to become used to memories of a young vigorous person that shared their body and memories leaving little else except some scars and some old stale socks lying around plus 2 or 3 pictures toRead More »
    • WIRE WRAP 101

      WIRE WRAP 101

      You might notice that many of my writings start with “Back in the day”. Not wanting to disappoint I will say that back in the day we used to use wire wrap technology when we needed a somewhat solid, somewhat reliably assembly. Given a readable schematic a good tech could return a working or near-working unit in a day or two depending on the completeness and accuracy of the schematic.Read More »
    • FROM GATES TO FPGA’S – PART 1: BASIC LOGIC

      FROM GATES TO FPGA’S – PART 1: BASIC LOGIC

      It’s time to do a series on logic including things such as programmable logic, state machines, and the lesser known demons such as switching hazards. It is best to start at the beginning — but even experts will enjoy this refresher and might even learn a trick or two. I’ll start with logic symbols, alternate symbols, small Boolean truth tables and some oddball things that we can do with basic logic. The narrative version is found in the video, with a full reference laid out in the rest of this post.Read More »
    • Tech Note on Op-Amps Driving Capacitance

      Tech Note on Op-Amps Driving Capacitance

      A great tech not on OP Amps driving capacitance. http://www.analog.com/library/analogDialogue/archives/31-2/appleng.html Q. How does capacitive loading affect op amp performance? A. To put it simply, it can turn your amplifier into an oscillator. Here's how: Op amps have an inherent output resistance, Ro, which, in conjunction with a capacitive load, forms an additional pole in the amplifier's transfer function. As the Bode plot shows, at each pole the amplitude slope becomes more negative by 20 dB/ decade. Notice how each pole adds as much as -90° of phase shift. We can view instability from either of two perspectives. Looking at amplitude …Read More »