Patent ID: 7528648
Filing Date: 2009-05-05
Classification: G05F

Abstract:
1. An apparatus comprising: a voltage generator coupled to a source of a transistor diode, the voltage generator configured to apply a bias voltage to the source of the transistor diode, wherein the voltage generator comprises an operational amplifier having an output coupled to the source of the transistor diode, a non-inverted input coupled to a band gap reference voltage source, and an inverted input coupled to the output of the operational amplifier through a voltage divider; a current biasing device coupled to a drain and a gate of the transistor diode, the biasing device configured to apply a current bias to the drain of the transistor diode; and a pass transistor having a gate coupled to the gate and the drain of the transistor diode, wherein an output voltage at the source of the pass transistor is approximately equal to the bias voltage.