Programmable differential amplifiers
Stephan I. Koutzarov · International Journal of Electronics · 1987
One differential amplifier circuit with two operational amplifiers (OAs) is given. Their gain can be changed by the aid of digital word (DW), generated by microcomputer or suitable digital circuit. Theoretical analysis of the circuit is given and the condition for flat frequency response (FR) is defined. Using commercially produced resistive matrices, two digitally controlled circuits are obtained. Some experimental results are included.