L4978 2A STEP DOWN SWITCHING REGULATOR

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 R_dson of 0.25Ω) to obtain very high efficency and high switching speed.

A switching frequency up to 300KHz 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 50V 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, soft-start, protection against feedback loop disconnection, inhibit for zero current consumption and thermal shutdown.

The device is available in plastic dual in line, DIP-8 for standard assembly, and SO16W for SMD assembly.

Key Features

• PROTECTION AGAINST FEEDBACK DISCONNECTION
• INHIBIT FOR ZERO CURRENT CONSUMPTION
• SOFT START FUNCTION
• THERMAL SHUTDOWN
• ZERO LOAD CURRENT OPERATION
• VOLTAGE FEEDFORWARD
• UP TO 2A STEP DOWN CONVERTER
• PRECISE 3.3V (±1%) INTERNAL REFERENCE VOLTAGE
• OPERATING INPUT VOLTAGE FROM 8V TO 55V
• SWITCHING FREQUENCY ADJUSTABLE UP TO 300KHz
• INTERNAL CURRENT LIMITING (PULSE-BYPULSE AND HICCUP MODE)
• OUTPUT VOLTAGE ADJUSTABLE FROM 3.3V TO 50V