Patent ID: 9590503
Date: 2017-03-07
CPC Classifications: H02M

Claim:
1. A switching converter, comprising: an input port, configured to receive an input voltage; an output port, configured to provide an output voltage; a power stage, having an input terminal, an output terminal and a control terminal, wherein the input terminal is coupled to the input port, and the output terminal is coupled to the output port; an energy stored circuit, having an input terminal coupled to the input port to receive the input voltage and an output terminal configured to provide a first bias voltage, wherein the first bias voltage maintains a predetermined time period after the input voltage becomes less than a threshold signal; a power conversion circuit, having an input terminal and an output terminal, wherein the input terminal is coupled to the input port to receive the input voltage, and the output terminal is configured to provide a second bias voltage; and a control circuit, having a first input terminal, a second input terminal, a third input terminal, a fourth input terminal and an output terminal, wherein the first input terminal is coupled to the output port, the second input terminal is configured to receive a discharge control signal, the third input terminal is coupled to the output terminal of the energy stored circuit to receive the first bias voltage, and the fourth input terminal is coupled to the output terminal of the power conversion circuit to receive the second bias voltage, and the output terminal is coupled to the control terminal of the power stage to provide a control signal based on the output voltage and a reference signal, wherein the control circuit is powered by either the first bias voltage or the second bias voltage; and wherein the control circuit is configured to discharge the output voltage based on the discharge control signal, when the input voltage is less than the threshold signal, the output voltage is fully discharged to ground by the control circuit, wherein the control circuit further comprising: a discharge switch, having a control terminal, wherein the discharge switch is configured to discharge the output voltage based on the discharge control signal.