The KA3842AC are fixed PWM controller for Off Line and DC to DC converter applications. The internal circuits include UVLO, low start up current circuit, temperature compensated reference, high gain error amplifier, current sensing comparator, and high current totem pole output for driving a POWER MOSFET. Also KA3842AC provides low start up current below 0.3mA and short shutdown delay time typ. 100ns. The KA3842AC has UVLO threshold of 16V(on) and 10V(off). The KA3842AC can operate within 100% duty cycle.