A new technique to achieve exact and controllable voltage gain relations in feedback amplifiers

This paper presents a new technique that allows the realization of exact voltage gain relations in feedback amplifiers. Basically, this technique exploits the imperfect subtraction characteristics of traditional differential amplifiers, as a means to nullify the closed-loop gain error of the complete configuration. The validation of the proposed technique was achieved following a simulation perspective, using a specially designed circuit, in a 350 nm CMOS process. The achieved results show that it is possible to arbitrarily reduce the gain error, improving the control precision of the subtraction process.