GND

OUT

IN

BIAS

SS

Under-Voltage

Lock-Out

Thermal

Shut Down

VREF

0.6V

ILIMIT

LP38859-x.x

LP38859

www.ti.com

SNVS337D – JUNE 2006 – REVISED OCTOBER 2011

Block Diagram

APPLICATION INFORMATION

EXTERNAL CAPACITORS

To assure regulator stability, input and output capacitors are required as shown in the Typical Application Circuit.

Output Capacitor

A minimum output capacitance of 10 µF, ceramic, is required for stability. The amount of output capacitance can

be increased without limit. The output capacitor must be located less than 1 cm from the output pin of the IC and

returned to the device ground pin with a clean analog ground.

Only high quality ceramic types such as X5R or X7R should be used, as the Z5U and Y5F types do not provide

sufficient capacitance over temperature.

Tantalum capacitors will also provide stable operation across the entire operating temperature range. However,

the effects of ESR may provide variations in the output voltage during fast load transients. Using the minimum

recommended 10 µF ceramic capacitor at the output will allow unlimited capacitance, Tantalum and/or

Aluminum, to be added in parallel.

Input Capacitor

The input capacitor must be at least 10 µF, but can be increased without limit. It's purpose is to provide a low

source impedance for the regulator input. A ceramic capacitor, X5R or X7R, is recommended.

Tantalum capacitors may also be used at the input pin. There is no specific ESR limitation on the input capacitor

(the lower, the better).

Copyright © 2006–2011, Texas Instruments Incorporated

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