Patent ID: 7119528
Filing Date: 2006-10-10
Classification: G05F

Abstract:
1. A voltage reference circuit, comprising: a first bias path comprising a first current source; a second bias path comprising a second current source; a third bias path comprising a third current source, a transistor with a source coupled to the third current source, and a resistor with a terminal coupled to a drain of the transistor, wherein a reference voltage is provided across the resistor; a first feedback loop, comprising a first operational amplifier with an inverting input coupled to the first bias path, a non-inverting input coupled to the second bias path, and an output coupled to the first, second, and third current sources; and a second feedback loop, comprising the transistor, and a second operational amplifier with an output coupled to a gate of the transistor, a non-inverting input coupled to the second bias path, and an inverting input coupled to the third bias path, wherein when electrical parameters of the first, second and third current sources are matched, current magnitudes of the first, second, and third current sources are essentially equal.