电源部分FR9886,这个路由用23V估计也行,电筒耐压25V,最低4.5V,可用充电宝供电。The FR9886 is a synchronous step-down DC/DC converter that provides wide 4.5V to 23V input voltage range and 2.5A continuous load current capability. The FR9886 fault protection includes cycle-by-cycle current limit, UVLO, output overvoltage protection and thermal shutdown. The adjustable soft-start function prevents inrush current at turn-on. This device uses current mode control scheme which provides fast transient response. Internal compensation function reduces external compensation components and simplifies the design process. In shutdown mode, the supply current is less than 1μA. The FR9886 is available in a SOP-8/SOP-8 exposed pad package, and provides good thermal conductance.