The MC34063A Series is a monolithic control circuit containing the primary functions required for DC−to−DC converters. These devices consist of an internal temperature-compensated reference, comparator, controlled duty cycle oscillator with an active current limit circuit, driver, and high current output switch. This series was specifically designed to be incorporated in Step−Down and Step−Up and Voltage-interverting applications with a minimum number of external components. Refer to Application Notes AN920A/D and AN954/D for additional design information.