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