Circuits & Schematics - Analogue Design

A self-heated Darlington transistor pair makes a simple, sensitive, and sturdy airflow sensor. But first an annoying non-linearity needs unbending. If you take a self-heated transistor in a TO-92 package and force it to hold a constant temperature ...

This page provides a detailed explanation of how the modified cascode light receiver circuit operates. The cascode technique in conjunction with an inductive load provides very high current to voltage conversion as well as very high speed. Upper ...

The circuit shown in Figure 1 is a complete microphone signal conditioning system based on a single SSM2166 integrated circuit. Designed primarily for voiceband applications, this integrated circuit provides amplification, RMS detection, limiting, ...

Here’s a neat and novel way of using a long-tailed pair to drive not just two but three LEDs. As everyone knows, rainbows always have pots of gold at their ends. This Design Idea reverses that, starting with a pot (no gold, alas) and ending ...

Circuits for converting 4 to 20 mA analog current loop signals to 0 to 20 mA may be hot topics, but hot implementations of those circuits are not. Circuit designs for conversion of 4 to 20 mA analog current loop signals, which are ubiquitous in ...

The ubiquity of the 4 to 20 mA current loop in analog process monitoring and control creates possibilities for peculiar designs of circuits for unusual accessory functions. Figure 1 shows an example. It does precision conversion of 4-20 mA to 0-20 ...

Ground-referenced loads are common in industry. This circuit implements current loop conversions for them. Recently, there have been several published Design Ideas on converting 0/20 mA to 4/20 mA current and 4/20 mA to 0/20 mA current as ...

A subtle change to a standard circuit can enhance its usefulness and even save a resistor. If there were a prize for the most trivial Design Idea (DI) of the year, this one would likely be high on the shortlist (if not at the top). Most DIs involve ...

Op amps tend to make analog design easy. Maybe sometimes too easy? Don’t get me wrong. I like operational amplifiers. Some of my best friends are op amps. They embrace such a wide range of varied capabilities, including low noise, high power, ...

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 ΔV BE temperature-sensing effect. ΔV BE temperature ...