Step-down circuit for DCDC converter

According to the step-down circuit for the DCDC converter, a power management chip ICU1 and a peripheral circuit of the power management chip ICU1 are used for step-down of input voltage, and due to the fact that in the peripheral circuit of the power management chip ICU1, the number and types of components are small, and control parameter design is simple, the step-down circuit can be used for PFC power factor correction topology and also can be used for DC power factor correction topology. The circuit is wide in application range, simple in circuit network, small in size, low in cost and suitable for large-scale batch use; in addition, the output voltage of the power supply can be accurately controlled through the power supply control loop, so that the step-down circuit can be effectively applied to a power supply circuit with relatively high power, and the voltage conversion efficiency of the step-down circuit is further improved. 一种DCDC变换器用的降压电路，利用电源管理芯片ICU1及其外围电路，对输入电压进行降压，由于电源管理芯片ICU1的外围电路中，元器件数量和种类均使用较