Patent ID: 8324957

Claim:
A current source comprising: an output MOSFET having a gate, the output MOSFET being controlled to have two different conductivity states for generating different currents; a first terminal of a first capacitor, having a first capacitance, coupled to the gate; a bias voltage source selectively coupled to the gate; a first switch coupled between a second terminal of the first capacitor and a first reference voltage; and a second switch coupled between the second terminal of the first capacitor and a second reference voltage, the first switch and the second switch being configured to switch oppositely, wherein, when the first switch conducts, the bias voltage source is coupled to the gate and, when the second switch conducts, the bias voltage source is decoupled from the gate, and wherein, when the first switch conducts, the output MOSFET is controlled to have a first conductivity and, when the second switch conducts, the output MOSFET is controlled to have a second conductivity lower than the first conductivity.