The NCP1340B8D1R2G is an ACDC converter High Voltage Quasi-Resonant Controller with Valley Lockout Switching from ON Semiconductor. The key features of the NCP1340B8D1R2G include low operating start-up current, improved valley lockout operation, variable pulse-by-pulse current limit, soft start with programmable ramp rate, synchronizing to a fixed external clock and frequency foldback. The NCP1340B8D1R2G also features protected catch diode, programmable output undervoltage, overvoltage, and turn-on delays. The device is ideal for use in SMPSs with high operating frequency switching, wide input range, and minimum size.