The MC34167, MC33167 series are high performance fixedfrequency power switching regulators that contain the primaryfunctions required for dc−to−dc converters. This series wasspecifically designed to be incorporated in step−down andvoltage−inverting configurations with a minimum number of externalcomponents and can also be used cost effectively in step−upapplications.These devices consist of an internal temperature compensatedreference, fixed frequency oscillator with on−chip timing components,latching pulse width modulator for single pulse metering, high gainerror amplifier, and a high current output switch.Protective features consist of cycle−by−cycle current limiting,undervoltage lockout, and thermal shutdown. Also included is a lowpower standby mode that reduces power supply current to 36 A.