If we replace the potentiometer VR1 with an AC signal plus DC bias signal in any of the previous Figures 3 to 17, the voltage controlled attenuators can become an amplitude modulator circuit instead.

Operational amplifiers (commonly called op amps) are a ubiquitous building block for designing electronic circuits. Today, these devices are fabricated as small integrated circuits, but the concept ...

In a balanced op-amp circuit, the op-amp inputs see equal impedances looking into the circuit. Balanced circuits provide better performance by cancelling some input errors and have a simple R F /R I ...