The circuit with valley switching technique

To implement soft switching in power management integrated circuit, a valley switching technique was proposed in this paper. Valley switching technique can significantly reduce the switching losses by discharging the parasitical capacitor across MOSFET before the switch is turned on. In order to improve the precision of valley detection, a principle of modulating hysteretic window was proposed to reduce the delay. The practical circuit was analyzed and simulated to verify this approach. The results showed that the performance of the circuit is consistent with expectations well.