A design for reducing the power dissipation in an integrated circuit for an image
pickup device. Placing a circuit block (2), such as for generating a driving
signal to an image pickup apparatus, in a standby state within a vertical blanking
period or horizontal blanking period reduces the power dissipation at the circuit
block (2). Since the blanking period is short, it is necessary to rapidly
restore normal operation from standby so as to ensure the standby time. A switch
(6) is provided between a terminal of the circuit block (2) and a
capacitor (4) that is provided for voltage regulation at the terminal. A
controller (8) turns off the switch (6) and disconnects the capacitor
(4) from the circuit block (2) in a period where the circuit block
(2) is placed in a standby state. As a result, variations in the amount
of stored charge in the capacitor (4) during standby are suppressed, and
while resetting to normal operation the time for returning the capacitor (4)
to the amount of stored charge for normal operation is shortened so that the reset
operation is performed rapidly.
