Patent ID: 7010419

Claim:
A signal processor comprising: a microprocessor for generating and supplying a control signal pulse train; a gain control circuit including a first switching device opened/closed by said control signal pulse train supplied from said microprocessor and a resistor for determining an amplification factor with respect to a signal voltage as input, said gain control circuit opening/closing said first switching device to vary a resistance value of said resistor in response to a pulse duty of said control signal pulse train, thereby adjusting said amplification factor with respect to said signal voltage; and a switched capacitor filter circuit including a second switching device opened/closed by said control signal pulse train supplied from said microprocessor and a charging/discharging capacitor connected to said second switching device, said switched capacitor filter circuit variably adjusting filter characteristics in response to a pulse frequency of said control signal pulse train, wherein said control signal pulse train is commonly supplied to said first and second switching devices.