TIME-SEQUENCE CONTROL CIRCUIT AND METHOD

摘要

A time-sequence control circuit and method. The control circuit comprises a freewheeling diode (D2) and an output capacitor (C). A drain electrode of the freewheeling diode is connected to a voltage output end (Vout). An end of the output capacitor is connected to the voltage output end, and the other end thereof is grounded. The control circuit also comprises a first freewheeling diode driver (M1) and a second freewheeling diode driver (M2). A first signal output end (M101) of the first freewheeling diode driver and a second signal output end (M201) of the second freewheeling diode driver are connected to a gate electrode (D201) of the freewheeling diode respectively. During power-on, the second signal output end transports a second drive signal to the freewheeling diode to drive the freewheeling diode to operate and discharge the backwards flowing voltage on the voltage output end through the freewheeling diode; and during power-off, the second signal output end transports a second drive signal to the freewheeling diode to drive the freewheeling diode to operate and discharge the residual voltage on the output capacitor through the freewheeling diode. The circuit and method eliminate the backwards flowing voltage on the voltage output end during power-on and guarantee that there is a discharge path for the residual voltage on the output capacitor during power-off.