ON Semiconductor NCP1251 series AC to DC Converter ICs

The NCP1251 is a highly integrated PWM controller capable of delivering a rugged and high-performance offline power supply in a tiny TSOP-6 package. With a supply range up to 28 V, the controller hosts a jittered 65 kHz or 100 kHz switching circuitry operated in peak current mode control. When auxiliary-side power begins to decrease, the controller automatically folds back its switching frequency to as low as 26 kHz. When power further decreases, the component enters skip-cycle while limiting peak current. The over-power protection (OPP) is a very difficult measure, especially when driving converter specifications with no-load standby requirements. ON Semiconductor’s exclusive integrated OPP allows you to fully utilize the highest power available with just two external resistors without affecting standby performance. It also combines latched overvoltage protection (OVP) on the same pin. To simplify implementation, automatic recovery OVP also monitors the Vcc line.