Patent ID: 8203383
Filing Date: 2012-06-19
Classification: G05F

Abstract:
1. An apparatus comprising: a current source; a first drain extended (DE) MOS transistor that is coupled to the current source at its drain; a second DE MOS transistor; a first current mirror transistor that is coupled to the source of the first DE MOS transistor at its drain and that is coupled to the current source at its gate; a second current mirror transistor that is coupled to the source of the second DE MOS transistor at its drain and that is coupled to the current source at its gate; a reference circuit that is coupled to the drain of the second DE MOS transistor and that generates a reference voltage at its output; a differential amplifier having: a first input that is coupled to the source of the first DE MOS transistor; a second input that is coupled to the source of the second DE MOS transistor; a reference input that is coupled to the output of the reference circuit; a first output that is coupled to the gate of the second DE MOS transistor; and a second output that is coupled to the gate of the first DE MOS transistor.