Patent ID: 7813150

Claim:
A regulator circuit, comprising: an energy source including a control input coupled to receive a control current, wherein an output of the regulator circuit is responsive to the control current; an optocoupler including: a photodiode coupled to conduct a diode current, wherein the diode current is responsive to the output of the regulator circuit; and a phototransistor optically coupled to the photodiode to generate an emitter current in response to the diode current; and a compensation network coupled to the control input of the energy source and to the phototransistor to generate a compensation current in response to an extrinsic parameter of the regulator circuit, such that the control current is a difference between the emitter current and the compensation current, wherein the compensation network includes a bipolar transistor, wherein a voltage V BE between a base and an emitter of the bipolar transistor adjusts by a first amount in response to the extrinsic parameter of the regulator circuit and wherein a reference voltage of the regulator circuit includes a voltage across the photodiode where the reference voltage adjusts by a second amount in response to the extrinsic parameter and wherein the second amount is proportional to the first amount.