Patent ID: 6903609
Filing Date: 2005-06-07
Classification: H03F

Abstract:
1. An operational amplifier comprising: a first output transistor connected to a high potential power supply and having a control terminal; a second output transistor connected between the first output transistor and a low potential power supply and having a control terminal, wherein the first and second output transistors generate an output signal at a node between the first output transistor and the second output transistor; and an idling current control circuit connected to the first and second output transistors controlling a current that flows through the first output transistor, among the first and second output transistors, in accordance with a voltage of the control terminal of the second output transistor to control an idling current of the first and second output transistors, wherein the idling current control circuit includes a transistor having a collector, which receives a control current provided to control the control terminal of the first output transistors, and an emitter connected to the control terminal of the second output transistor.