Circuits & Schematics - Analogue Design - 8

Low-frequency filters, particularly at audio frequencies, usually take the form of active filters. These filters eliminate expensive inductors with windings of many turns. Both analog and digital active filters are most compatible with large-scale ...

You can use a photoelectric FET as a variable resistor or a potentiometer in combination with a fixed resistor. The H11F3M photoelectric FET has an isolation voltage of 7.5 kV, enabling you to safely control high-voltage circuit parameters. The ...

Many applications require a sinusoidal reference voltage synchronized to the ac line voltage. You cannot derive such a reference voltage directly from the ac line because the waveform of the ac line is distorted because of nonlinear loads connected ...

You typically accomplish overvoltage or surge protection at circuit inputs by connecting diodes to the supply rails, connecting zener diodes to ground, or connecting transzorbs to ground. Unfortunately, for high-energy surges at the inputs, ...

It’s just an unavoidable fact: electronic components’ parameters drift with temperature. Even the most stable voltage references, op amps, crystal oscillators, etc., have non-zero temperature coefficients. These effects can be mitigated ...

Some circuits need a constant-current source that does not necessarily connect to a power-supply rail or to ground. The circuit in the Figure 1 shows a simple method for achieving that configuration. Figure 1. The simple method achieves a ...

At least two classic ways exist to address applications requiring sampling of a sum of analog voltages. The most common way is to cascade a classic analog adder and a sample-and-hold amplifier. A classic analog adder is an op amp plus at least ...

With linear regulators, you measure dropout voltage, V IN V OUT , at the minimum input voltage for which the IC sustains regulation. Low dropout means longer battery life, because the load circuit continues to operate while the battery discharges ...

The circuit in this Design Idea anticipates, or jumps instantly to, the final voltage of an input-signal change. It relies on the fact that the intended input signal changes exponentially with a known time constant. This circuit was adapted from a ...

A self-biasing thermistor circuit had an overall dominant thermal/ electrical time constant as small as 25 msec but had a significantly rounded response following a square (thermal) input pulse of 100 msec; the source was a pulsed blue LED. A ...