Circuits & Schematics

Variable regulated power supplies are handy tools found on well-equipped electronics lab benches. The symmetrical varieties that produce equal voltage outputs of opposite polarity, are even more so. Figure 1’s version of a symmetrical 0 V to ...

The ubiquitous variable resistance circuit network shown in Figure 1 Figure 1. Classic adjustable resistance; R MAX = R S + R R ; R MIN = R S . But a sticky question remains: What if the polarity of the V A V B differential is subject to reversal? ...

This is one real-life quest: How do we increase the output voltage of a step-up converter? If you have unlimited access to the right ICs, you are one lucky dog, but what if you don’t? Or maybe you are limited to a specific chip due to ...

It’s easy to mute a balanced signal line. Simply short the terminals or break the signal path. But when the line is unbalanced (single ended) and the output has strong dc bias, trying to mute the circuit with these methods will affect the ...

Zeroing out temperature variations on a production line is a challenging task when the device to be compensated has a temperature coefficient that varies in both magnitude and sign from unit to unit. This simple circuit can meet the challenge (see ...

I was surprised recently when a (nearly) two-decade-old design idea of mine for take-back-half temperature control ( Ref. 1 ) got a question from reader John Louis Waugaman. John says he needs a way to control the temperature of batches of rising ...

The excellent linearity of integrated-circuit temperature sensors makes them ideal for direct analog compensation of the thermally induced errors inherent in many circuits. For example, a negative-sloped temperature sensor could compensate for an ...

As a genre, DACs are low power devices with power and current output capabilities limited to the milliwatt and milliampere range. There is, of course, no fundamental reason they can’t be teamed up with suitable power output stages, which is ...

A two-terminal current source using the basic circuit of Figure 1a can be enhanced by adding on an independent subcircuit that uses degeneration of a PNP transistor to achieve zero temperature coefficient (tempco or TC). This low-cost design is the ...

A common technique for implementing PWM involves comparing a triangular waveform of fixed amplitude and frequency with a variable dc voltage level. Although this approach results in a PWM signal of precise frequency and with duty cycle variable ...