The PWM-type DC/DC converters for AC/DC supplies the optimum system for all products in which an outlet is present. It is compatible with both insulated and noninsulated, and various types of low-power consumption converters can be easily designed. The built-in 900V startup circuit contributes to low power dissipation. A highly flexible power supply design is achieved by externally installing a current detection resistor for switching. Because of the use of current mode control, the current is limited every cycle, providing excellent performance in bandwidth and excessive response. The switching frequency is fixed at 100 kHz. When turned light load, the frequency is reduced to achieve high efficiency. Built-in frequency hopping function contributes to low EMI. Built-in 900V switching MOSFET enables easy designing. The SSOP-A20_16A high heat dissipation, surface mount type package is used to help reduce mounting costs.