SP2637AF is a high perfomance offline PSR power switch for low power AC/DC charger and adapter applications. It operates in primary-side sensing and regulation.Thus, opto-coupler and TL431 are not required. In CC control, the output current and power setting can be adjusted extemally by the sense resistor Rcs at CS PIN. In CV control,multi-mode operations are utilized to achieve high performance and high efficiency. In addition, good load regulation is achieved by the built-in cable drop compensation. SP2637AF operates in PFM in CC mode, and it operates in PWM+PFM in CV mode with frequency reduction at light/medium load. The chip consumes very low operation current. It achieves less than 75mW standby power to meet all global energy efficiency regulations. SP2637AF offers comprehensive protection coverage with auto-recovery feature including Cycle-by-Cycle current limiting, VDD over voltage protection (OVP),FB over voltage protection,load short circuit protection, VDD under voltage lockout (UVLO), OTP etc. SP2637AF is offered in SOP8 packages.