Patent ID: 8278889

Claim:
A control system for turning off a synchronous rectifier in an inductor-based power converter, comprising: a comparator having an input coupled to an inductor in the power converter to obtain an indication of substantially zero inductor current, and having an output coupled to the synchronous rectifier to switch off the synchronous rectifier to reduce or eliminate negative inductor current; an adjustable compensation offset voltage source coupled to an input of the comparator; a compensation offset voltage source controller operating only in a discontinuous or transition mode coupled to the output of the comparator and to the compensation offset voltage source and being operable to adjust an output value of the compensation offset voltage source for an offset voltage of the comparator and propagation delays in the control system by determining a timing relationship between a transition of the output of the comparator and the indication of substantially zero inductor current; and an up/down counter provided as the compensation offset voltage source.