EDN Design Ideas (DI) published a design of mine in May of 2025 for a passive two-way current mirror topology ( Ref. 1 ) that, in analogy to optical two-way mirrors, can reflect or transmit. That design comprises just two BJTs and one diode. But ...
Current sources are useful in many areas of electronics, such as voltage and current division, current transmitters, excitation of thermistors, RTDs, bridges, potentiometers, and circuit biasing. Current sources are either fixed- or ...
Current mirrors are a commonly useful circuit function, and sometimes high precision is essential. The challenge of getting current mirrors to be precise has created a long list of tricks and techniques. The list includes matched transistors, ...
The Norton amplifier topology brings back the essence of analog design by using clever circuit techniques to deliver strong performance with minimal components. It is not about a brand name it’s about a timeless analog philosophy that ...
It’s just a fact of life. A BJT wired in common emitter, even after compensating for the effects of device and temperature variations, still isn’t a perfect current source. One of the flaws in the ointment is the Early effect of ...
High school trigonometry combined with four-quadrant multipliers can be exploited to yield sinusoidal frequency doublers. Nothing non-linear is involved, which means no possibly strident filtering requirements. Starting with some sinusoidal signal ...
A Planet Analog article, “2N3904: Why use a 60-year-old transistor?” ( Ref. 1 ) by Bill Schweber, inspired some interest in this old transistor and how it’s commonly used, and if any uncommon uses might exist. Here’s one we ...
The typical anti-log circuit The basic anti-log amplifier looks like the familiar circuit of Figure 1. Figure 1. The typical anti-log circuit has uncertainties related to the reverse current, I S , and is sensitive to temperature. The approximate ...
Back on December 3, 2024, a Design Idea (DI) was published, “Single-supply single-ended inputs to pseudo class A/B differential output amp” ( Ref. 1 ), which created some discussion about using the circuit as a full wave rectifier. The ...
Abstract This article discusses the applications of an operational amplifier for electrochemical gas sensors such as ethanol and carbon monoxide (CO). It also discusses the desired performance to provide optimum results for accurate measurement of ...