Patent ID: 9628034
Date: 2017-04-18
CPC Classifications: G09G,H03F

Claim:
1. An operational amplifying circuit comprising: a control circuit comprising a first input terminal configured to receive an input voltage, a second input terminal and an output terminal connected to the second input terminal, the control circuit being configured to, in response to the input voltage transitioning to a first level, change a voltage level of a pull-up node and a voltage level of a pull-down node to a second level that is different from the first level; a pull-up transistor gated to the voltage level of the pull-up node to provide a power supply voltage to the output terminal; a pull-down transistor gated to the voltage level of the pull-down node to connect the output terminal to a ground voltage; a first bias circuit configured to provide a first bias current to the control circuit; a bias voltage generating circuit configured to generate a bias voltage in response to the voltage level of at least one of the pull-up node and the pull-down node reaching a threshold voltage level; and a second bias circuit gated to the generated bias voltage to provide a second bias current to the control circuit.