Patent ID: 7251169

Claim:
A voltage supply circuit comprising: a first differential amplifier that receives a voltage of an output node and a first voltage as input voltages, and activates its output signal when the voltage of said output node is lower than said first voltage; a second differential amplifier that receives the voltage of said output node and a second voltage which is higher than said first voltage as input voltages, and activates its output signal when the voltage of said output node is higher than said second voltage; a first driving circuit that connects said output node to a high power supply line in response to the activation of the output signal of said first differential amplifier, and connects said output node to a low power supply line in response to the activation of the output signal of said second differential amplifier; and a second driving circuit that connects said output node to said high power supply line in response to the activation of the output signal of said first differential amplifier, and connects said output node to said low power supply line in response to the activation of the output signal of said second differential amplifier, only during an activation period of a drivability control signal, wherein each of said first and second differential amplifiers includes a differential amplifying part that activates the output signal according to a magnitude relation between the input voltages and a current control part that is connected to said differential amplifying part, and increases a bias current in response to the activation of said drivability control signal.