DESCRIPTION
The L4976 is a step down monolithic power switching regulator delivering 1A 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.
A switching frequency up to 250KHz is achievable (the maximum power dissipation of the packages must be observed). A wide input voltage range between 8V to 55V and output voltages regulated from 3.3V to 40V cover the majority of today’s applications.
Features of this new generations of DC-DC converter include pulse-by-pulse current limit, hiccup mode for short circuit protection, voltage feedforward regulation, protection against feedback loop disconnectionand thermal shutdown.
The device is available in plastic dual in line, MINIDIP 8 for standard assembly, and SO16W for SMD assembly.

■ UP TO 1A STEP DOWN CONVERTER
■ OPERATING INPUT VOLTAGE FROM 8V TO 55V
■ PRECISE 5.1V REFERENCE VOLTAGE
■ OUTPUT VOLTAGE ADJUSTABLE FROM 3.3V TO 50V
■ SWITCHING FREQUENCY ADJUSTABLE UP TO 500KHz
■ VOLTAGE FEEDFORWARD
■ ZERO LOAD CURRENT OPERATION
■ INTERNAL CURRENT LIMITING (PULSE-BY-PULSE AND HICCUP MODE)
■ PROTECTION AGAINST FEEDBACK DISCONNECTION
■ THERMAL SHUTDOWN