Patent ID: 7636010
Filing Date: 2009-12-22
Classification: G05F

Abstract:
1. A voltage reference circuit comprising: a bandgap reference circuit for generating a bandgap reference voltage and a reference current, a first node and a second node of the bandgap reference circuit being between the bandgap reference voltage and a negative temperature coefficient voltage, the bandgap reference voltage at least including: a first operation amplifier having an output terminal; and a first transistor having a first terminal coupled to a power supply, a second terminal coupled to the bandgap reference voltage and a control terminal coupled to the output terminal of the first operation amplifier; a second transistor having a first terminal coupled to the power supply, a second terminal for mirroring the reference current from the bandgap reference circuit to provide a first current and a control terminal coupled to the output terminal of the first operation amplifier; and a compensation controller, coupled to the bandgap reference circuit, the compensation controller converting a node voltage of the second node into a second current and performing current subtraction on the first current and the second current to provide a compensation feedback current to the first node of the bandgap reference circuit, so that the bandgap reference voltage being temperature compensated.