Patent ID: 7940824

Claim:
A current driver to provide an incremental current to an output device, comprising: a current channel configured to provide a pre-determined incremental output current, the current channel comprising: a current mirror amplifier comprising emitter degeneration; a startup transistor electrically coupled to the current mirror amplifier and configured to generate a direct current bias on the current mirror amplifier; a beta helper circuit electrically coupled to the current mirror amplifier and the startup transistor, configured to maintain the direct current bias on the current mirror amplifier; and a cutoff transistor electrically coupled to an emitter terminal of a current mirror amplifier transistor and to a reference voltage, and configured to selectively couple the emitter terminal to the reference voltage to conduct the pre-determined output current; and an output stage electrically coupled to an output of the current mirror amplifier and to an output device, wherein the output stage is configured to provide a current gain in response to the cutoff transistor electrically coupling the emitter terminal to the reference voltage.