CPC H02M 1/0029 (2021.05) [H02M 1/08 (2013.01); H02M 1/4225 (2013.01); H02M 3/156 (2013.01); H02M 3/157 (2013.01)] | 18 Claims |
1. A control circuit of a switching power supply circuit, wherein the switching power supply circuit comprises a power switch and an inductor connected in series between a voltage input terminal and ground, an input voltage is applied to the voltage input terminal, an output voltage is provided by a switching node between the power switch and the inductor, and the control circuit comprises:
a driving unit, configured to provide a driving signal to a control terminal of the power switch according to a switch control signal; and
a control unit, which is connected with the switching node to obtain a switching voltage, configured to obtain a logic control signal according to a comparison result between the switching voltage and a preset voltage, and configured to control the driving unit to provide the driving signal with different driving strengths according to the logic control signal, so as to adjust a speed of turning the power switch off,
wherein, the driving signal is configured to charge or discharge the control terminal of the power switch, during a phase for discharging the control terminal of the power switch, the driving signal has a first driving strength when the switching voltage is lower than the preset voltage, and the driving signal has a second driving strength lower than the first driving strength when the switching voltage is greater than/equal to the preset voltage.
|