ELECTRIC AMPLIFIER CIRCUIT FOR AMPLIFYING AN OUTPUT SIGNAL OF A MICROPHONE

摘要

An electric amplifier circuit for amplifying an output signal of a microphone comprises a supply input terminal (V10) to apply a supply potential (VDDA) for operating the electric amplifier circuit and a differential amplifier (110) having a first input terminal (E110a) for applying the output signal of the microphone (20), a second input terminal (E110b) and an output terminal (A110) for outputting an amplified output signal (OUT) of the microphone (20). A feedback path (FP) is provided between the output terminal (A110) of the differential amplifier (110) and the second input terminal (E110b) of the differential amplifier (110). A charge supplying circuit (120) is coupled to the feedback path (FP) to supply an amount of the charge to the feedback path (FP) in dependence on the supply potential (VDDA).The amount of charge supplied to the feedback path may be dependent on a change of the supply potential (VDDA).