1

Date: 5/25/04

SPX3940 1A Low Dropout Voltage Regulator

© Copyright 2004 Sipex Corporation

1A Low Dropout Voltage Regulator

Fixed Output, Fast Response

SPX3940

DESCRIPTION

FEATURES

■ 1% Output Accuracy SPX3940A

■ Guaranteed 1.5A Peak Current

■ Low Quiescent Current

■ Low Dropout Voltage of 280mV at 1A

■ Extremely Tight Load and Line Regulation

■ Extremely Fast Transient Response

■ Reverse-battery Protection

■ Internal Thermal Protection

■ Internal Short Circuit Current Limit

■ Replacement for LM3940

■ Standard SOT-223, TO-220

and TO-263 packages

®

The SPX3940 is a 1A, accurate voltage regulators with a low drop out voltage of 280mV(typical)

at 1A. These regulators are specifically designed for low voltage applications that require a low

dropout voltage and a fast transient response. They are fully fault protected against over-current,

reverse battery, and positive and negative voltage transients.

The SPX3940 is offered in 3-pin SOT-223, TO-220 & TO-263 packages. For a 3A version, refer

to the SPX29300 data sheet.

APPLICATIONS

■ Powering VGA & Sound Card

■ Automotive Electronics

■ LCD Monitors

■ Cordless Telephones

SPX3940

V

OUT

V

IN

+

6.8µF

+

10µF

1

2

3

Figure 1. Fixed Output Linear Regulator.

TYPICAL APPLICATIONS CIRCUIT

■ SMPS Post-Regulator

■ Laptop, Palmtop, and Note-

book Computer

■ High Efficiency Linear Power

Supplies

■ Portable Instrumentation

■ Constant Current Regulators

12

3

SPX3940

3 Pin TO-263

GND

V

IN

V

OUT

Now Available in Lead Free Packaging