DESCRIPTION

The L4978 is a step down monolithic power switching regulator delivering 2A at a voltage between 3.3V and 50V (selected by a simple external divider). Realized in BCD mixed technology, the device uses an internal power D-MOS transistor (with a typical Rdson of 0.25Ω) to obtain very high efficency and high switching speed.

Features

■ UP TO 2A STEP DOWN CONVERTER

■ OPERATING INPUT VOLTAGE FROM 8V TO

55V

■ PRECISE 3.3V (±1) INTERNAL

REFERENCE VOLTAGE

■ OUTPUT VOLTAGE ADJUSTABLE FROM

3.3V TO 50V

■ SWITCHING FREQUENCY ADJUSTABLE UP

TO 300KHz

■ VOLTAGE FEEDFORWARD

■ ZERO LOAD CURRENT OPERATION

■ INTERNAL CURRENT LIMITING (PULSEBYPULSE AND HICCUP MODE)

■ INHIBIT FOR ZERO CURRENT

CONSUMPTION

■ PROTECTION AGAINST FEEDBACK

DISCONNECTION

■ THERMAL SHUTDOWN

■ SOFT START FUNCTION