Patent ID: 7218170

Claim:
A current mirror with selectable filter poles for providing a DC bias signal, comprising: a current source coupled to a supply; a first MOSFET having a drain coupled to receive current from the current source, a source coupled to a circuit common, and a gate coupled to the drain of the first MOSFET; a second MOSFET having a drain coupled to provide the bias signal and a source coupled to circuit common; a first selectable resistor coupled between a gate of the first MOSFET and a gate of the second MOSFET, respectively, wherein the first selectable resistor corresponds to a selectable filter pole for a low pass filter; a resistor coupled between the gates of the first and second MOSFETs in parallel to the first selectable resistor; a logic and bias circuitry coupled to select the first selectable resistor; and at least one capacitor-configured MOSFET coupled between the gate of the second MOSFET and circuit common, wherein the first selectable resistor and resistor provide one of a fast settle time and improved filtering according to logic and bias circuitry voltage.