The µA78S40 is a switching regulator subsystem, consisting of a temperature compensated voltage reference, controlled–duty cycle oscillator with an active current limit circuit, comparator, high–current and high–voltage output switch, capable of 1.5 A and 40 V, pinned–out power diode and an uncommitted operational amplifier, which can be powered up or down independent of the IC supply. The switching output can drive external NPN or PNP transistors when voltages greater the 40 V, or currents in excess of 1.5 A, are required. Some of the features are wide–supply voltage range, low standby current, high efficiency and low drift. TheµA78S40 is available in commercial (0°to + 70°C), and automotive (–40°to + 85°C) temperature ranges. Some of the applications include use in step–up, step–down, and inverting regulators, with extremely good results obtained in battery–operated systems.

•Output Adjustable from 1.25 V to 40 V
•Peak Output Current of 1.5 A Without External Transistor
•80 dB Line and Load Regulation
•Operation from 2.5 V to 40 V Supply
•Low Standby Current Drain
•High Gain, High Output Current, Uncommitted Op Amp