Patent ID: 8638167
Filing Date: 2014-01-28
Classification: H03F

Abstract:
1. An operational amplifier, for driving a load, comprising: an input stage, for providing an intermediate signal according to an input signal; an output stage, comprising an output node, for providing a driving signal according to the intermediate signal; an output enable switch, coupled between the output node and the load, being turned on during an output enable period, to drive the load with the driving signal, the output enable period having a start time point; an internal circuit, coupled between the input stage and the output stage; and a coupling effect reduction circuit, coupled between the internal capacitor and the output node or between the internal capacitor and the input stage, being turned off during an operational period that begins from the start time point, so as to prevent coupling charge generated when the output enable circuit is turned on from affecting operational voltage levels of the input stage.