Patent ID: 7449873

Claim:
A voltage controlled current source with a control voltage input and a load current output, comprising: a current set terminal for coupling to a current set resistor; a regulating driver for setting gate bias voltages for transistors in selected current legs, corresponding to a control voltage applied to the control voltage input of the regulating driver, and for providing a regulated voltage across the current set resistor, thereby allowing a reference current to flow through the current set resistor and also to flow through at least one selected current leg; and a current mirror comprising the selected current legs that mirror the reference current to the load current output; wherein the current mirror includes multiple current legs all having the same gate bias voltages supplied by said regulating driver, at least one of said selected current legs being coupled to conduct said reference current to said current set resistor; the current mirror further includes switches coupled between each current leg and the current set resistor; and other switches coupled between each current leg and the load current output.