L4976| Datasheet

L4976, L4976D, L4976D013TR

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L4976
1A step down switching regulator
Features

Up to 1A step down converter Operating input voltage from 8v to 55v Precise 5.1V reference voltage Output voltage adjustable from 0.5V to 50V Switching frequency adjustable up to 300kHz Voltage feedforward Zero load current operation Internal current limiting (pulse-bypulse and hiccup mode) Protection against feedback disconnection Thermal shutdown
DIP8 SO16W

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 DMOS transistor (with a typical Rds(ON) of 0.25) 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 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 disconnection and thermal shutdown. The device is available in plastic dual in line, MINIDIP 8 for standard assembly, and SO16W for SMD assembly.

Figure 1.

Typical application circuit
5 R1 20K 3 C1 220uF 63V C7 220nF C2 2.7nF 2 7

Vi=8V to 55V 8

L4976
4 1 6 L1 260uH (77120) D1 GI SB360 C8 330uF VO=3.3V/1A

R2 9.1K C4 22nF

C6 100nF

April 2007

Rev 7

1/17
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