The SC1101 is a versatile, low-cost, voltage-mode PWM controller designed for use in single ended DC/ DC power supply applications. A simple, fixed-voltage buck regulator can be implemented using the SC1101 with a minimum of external components. Internal level shift and drive circuitry eliminates the need for an expensive p-channel, high-side switch. The small device footprint allows for compact circuit design. SC1101 features include a temperature compensated voltage reference, triangle wave oscillator, current limit comparator, frequency shift over-current protection, and an internally compensated error amplifier. Pulse by pulse current limiting is implemented by sensing the differential voltage across an external resistor, or an appropriately sized PC board trace. The SC1101 operates at a fixed frequency of 200kHz, providing an optimum compromise between efficiency, external component size, and cost.