Patent ID: 8450989

Claim:
A power system comprising: a switching circuit configured to conduct electrical current through at least one switch device thereof during an activation interval of the at least one switch device in response to a periodic control signal; a tracking system configured to provide a tracking signal indicative of a predetermined point of the activation interval; and sampling circuitry configured to measure an electrical signal at the predetermined point of the activation interval in response to the tracking signal, the electrical signal being at least one of a voltage and current corresponding to the electrical current through the at least one switch, such that the sampling circuitry provides an output signal indicative of an average electrical current, wherein a tracking circuit comprises a first comparator having a first input coupled to the measured the electrical signal for comparing a value of the measured electrical signal to a reference voltage, output of the first comparator controlling timing of the periodic control signal so that a peak voltage of the sample will be substantially the reference voltage.