Patent ID: 8269478

Claim:
A voltage regulator circuit, comprising: an output node at which said circuit's output voltage is provided; a supply current coupled to said output node; a first bipolar transistor; a second bipolar transistor, said first and second bipolar transistors arranged to operate at different current densities; a first resistor connected between said transistors such that the difference between the base-emitter voltages of said first and second bipolar transistors (ΔV BE ) appears across said first resistor; a second resistor having its first terminal directly connected to said output node and its second terminal connected to the base of said first bipolar transistor such that said second resistor conducts the current in said first resistor and said first bipolar transistor; a third bipolar transistor having its base directly connected to the base of said first bipolar transistor; and a current mirror comprising first and second transistors, each of which has first, second and third terminals and is arranged to conduct current between said first and second terminals in response to a voltage applied to said third terminals, both of said first terminals directly connected to said output node and both of said second terminals directly connected to respective ones of said second and third bipolar transistors, said current mirror arranged to balance the collector current of one of said second and third bipolar transistors with an image of the collector current of said first bipolar transistor when said output node is at a unique operating point.