Patent ID: 7952894

Claim:
A synchronous rectifier control device, coupled with a secondary side of a forward synchronous rectifier circuit, which includes: a status detecting unit, which receives a detecting signal representing the condition on the secondary side of the forward synchronous rectifier circuit, as well as at least one reference signal, in which a first synchronous control signal is generated accordingly; an analog circuit, which is coupled with the status detecting unit, and generates a delay signal based on the first synchronous control signal; a first counter, which is coupled with the status detecting unit and the analog circuit and receives a clock signal, and counts as well as generates a first counting signal according to the first synchronous control signal, the clock signal and the delay signal; a second counter, which is coupled with the first counter and the status detecting unit and receives the clock signal, the second counter generates a second counting signal according to the first synchronous control signal, the clock signal and the first counting signal; and a signal processing unit, which is coupled with the status detecting unit and the second counter, so as to generate a second synchronous control signal based on the first synchronous control signal and the second counting signal.