Separation type synchronous rectification control circuit, control device therefor, and separation type synchronous rectification control method

摘要

The present invention provides a separate synchronous rectification control circuit, a control device thereof, and a separate synchronous rectification control method. The control circuit according to the present invention includes a power supply module, a reference module, a comparator module, a primary side continuity determination unit, a secondary side discontinuity prediction unit, a logic unit, and a drive unit. The control apparatus according to the present invention includes a transformer, a bypass capacitor for providing a stable voltage, a time constant setting resistor used for determination of a time constant setting of the primary side to be conducted and a prediction of discontinuous time prediction of the secondary side. Based on the current flowing from the time setting terminal, it is determined whether or not the primary side is conductive, the secondary side discontinuous time is predicted, and the conduction or cutoff is determined based on the determination and the prediction result. A synchronous rectification control circuit for generating a logic control signal and driving the synchronous rectification transistor, and an output capacitor connected to a voltage terminal of the synchronous rectification control circuit and used for the output of the capacitor. The present invention employs a primary-side continuity determination circuit, a secondary-side discontinuity time prediction circuit, and a dual voltage determination mechanism, so that the synchronous rectification transistor can operate accurately in complex system work situations. .