Patent ID: 7142401

Claim:
An active circuit for being coupled to a reactive circuit that provides an output voltage, comprising: a control regulator circuit having an output for providing pulses; a first switch that has an input coupled to the output of the control regulator curcuit, a power supply input coupled to a power supply terminal, and an output that is an output of the active circuit; a pulse shaper having an input coupled to the control regulator circuit and an output; a reference voltage generator for providing a reference voltage that changes in response to changes in a voltage at the power supply terminal; and an integrator having a first input coupled to the output of the pulse shaper, a second input for receiving the reference voltage, and an output for providing a signal indicative of a current level supplied at the output voltage, wherein: the reference voltage generator is responsive to a first programming signal in addition to being responsive to the voltage at the power supply terminal; the first programming signal is representative of the output voltage; and the first programming signal is the output voltage.