System and method for controlling a gain circuit

摘要

A circuit (12) for controlling the gain of a gain cell (14) is provided. Circuit (12) comprises a circuit (16) for generating a control current. A circuit (22) generates a reference voltage. A circuit (18) uses the reference voltage to generate a first control voltage. A circuit (20) uses the control current to generate a second control voltage. The first and second control voltages comprise a differential control output of circuit (12). The gain of the gain cell is exponentially related to the control current.