BP85956D is a switching power supply driver chip with high performance, high integration, and low standby power consumption. It is suitable for Buck and Buck-Boost converter topology applications with full voltage 85-265VAC input. BP85956D integrates a 650V high-voltage MOSFET, high-voltage start-up and self-power supply circuit, current sampling circuit, and output voltage sampling resistor. By adopting advanced control technology, it can achieve excellent constant voltage output characteristics without external VCC capacitor and loop compensation, reducing the number of peripheral devices, saving system cost and volume, and improving reliability at the same time.