The FS6X1220R is specially designed for an off-line DCDC converters with minimal external components. This device is a current mode PWM controller combined with a high voltage power SenseFET in a single package. The PWM controller includes integrated fixed frequency oscillator, line under voltage lockout, sleep on/off function, thermal shutdown protection, over voltage protection, pulse-by-pulse current limit and temperature compensated precise current sources for a loop compensation. Compared with discrete MOSFET and PWM controller solution, the FS6X1220R can reduce total cost, component count, size and weight simultaneously increasing efficiency, productivity, and system reliability. This device is well suited for DC to DC converter applications up to 40W of output power.