Patent ID: 7414457

Claim:
A bias voltage generating circuit for generating a predetermined reference voltage suitable for a power ON state and a standby voltage suitable for a power OFF state as a bias voltage in response to the power ON/OFF switchover comprising: a reference voltage generator for generating the reference voltage; a standby voltage generator for generating the standby voltage; a bias wiring for outputting the bias voltage; a voltage return unit comprising a charge storing element and a first switch for connecting or disconnecting the charge storing element to the bias wiring; and a drive controller for controlling the standby voltage generator and the voltage return unit, wherein the drive controller switches over the first switch from an OFF state to ON state before the power ON state is switched to the power OFF state to thereby charge the bias voltage in the charge storing element, and switches over the first switch from an OFF state to ON state before the power OFF state is switched to the power ON state to thereby discharge the bias voltage charged in the charge storing element to an output load capacitance of the bias voltage generating circuit, and thereafter, the drive controller further approximates the bias voltage to the predetermined voltage and then starts an operation of shifting the bias voltage to the predetermined voltage before the power ON starts.