The MC34166, MC33166 series are high performance fixed frequency power switching regulators that contain the primary functions required for dctodc converters. This series was specifically designed to be incorporated in stepdown and voltageinverting configurations with a minimum number of external components and can also be used cost effectively in stepup applications. These devices consist of an internal temperature compensated reference, fixed frequency oscillator with onchip timing components, latching pulse width modulator for single pulse metering, high gain error amplifier, and a high current output switch. Protective features consist of cyclebycycle current limiting, undervoltage lockout, and thermal shutdown. Also included is a low power standby mode that reduces power supply current to 36 A. Output Switch Current in Excess of 3.0 A