Circuits & Schematics

Manufacturers of optocouplers characterize their devices for CTR (current-transfer ratio), and an optocoupler’s data sheet will list its CTR ranges. Unfortunately, the CTR range may be too wide for some applications, requiring you to screen ...

Few methods for analog to digital conversion are more “mature” than the classic combination of a voltage-to-frequency converter (VFC) with a counter. VFC digitization is naturally integrating, so good noise rejection is inherent, as is ...

Systems using line receivers for differential input signals require an adequate self-test capability. Using an LM339 (a quad differential comparator), you can provide this capability by constructing the configuration shown in the Figure 1. ...

This circuit of only a few components is powered by two AA batteries and features a mode that extends its power savings. Imagine a smart light switch which not only automatically turns itself on when it gets dark, but also adjusts its level of ...

It’s interesting, useful, and fun that basic electronic topologies often turn out to have utility in multiple and surprisingly different applications. Figure 1 shows an example of such a circuit. It’s a charge pump voltage inverter ...

This Design Idea mates a precision current source IC with precision difference amp chips to create a programmable current source or sink. The resistor-programmable current source/sink in Figure 1 illustrates the basic topology, taking advantage of ...

In many applications, there are requirements of low power, high performance differential amplifiers to convert small differential signals to a readable ground referenced output signal. Input voltages at two inputs usually share a large common-mode ...

It is advantageous to know if there is a valid signal on a differential signal bus. This Design Idea detects differential data transmission and reports a loss of signal (LOS) to a microcontroller or other monitoring device. The circuit of Figure 1 ...

Many applications require special differential amplifiers that achieve both high performance and low power dissipation. A simple solution is to use a dual non-inverting precision amplifier with a resistive gain network, but the DC common-mode level ...

When the Sun is shining and illumination is needed inside a dimly lit interior space, a popular, proven, and highly efficient solution is to utilize the energy of available sunlight in the simplest and most sustainable fashion conceivable: Opening ...