OUT

GND

LP3855-2.5

10 2F

INPUT

10 2F

SD

SD

**

SENSE

2.5V, 1.5A

3.3V ± 10%

* TANTALUM OR CERAMIC

IN

OUT

IN

GND

LP3852-2.5

10 2F

INPUT

10 2F

ERROR

**

SD

SD

**

ERROR

2.5V, 1.5A

3.3V ± 10%

* TANTALUM OR CERAMIC

LP3852, LP3855

SNVS174I – FEBRUARY 2003 – REVISED FEBRUARY 2015

www.ti.com

10 Application and Implementation

NOTE

Information in the following applications sections is not part of the TI component

specification, and TI does not warrant its accuracy or completeness. TI’s customers are

responsible for determining suitability of components for their purposes. Customers should

validate and test their design implementation to confirm system functionality.

10.1 Application Information

The LP3852 and LP3855 devices can provide 1.5-A output current with 2.5-V to 7-V input. A minimum 10-uF

output capacitor is required for loop stability. An input capacitor of at least 10 µF is required . Pin SD must be

tied to input if not used. For LP3852, ERROR pin should be pulled high through a pullup resistor. For LP3855, if

the sense option is not required , the SENSE pin must be connected to the OUT pin.

10.2 Typical Applications

Figure 18. LP3852 Typical Application

Figure 19. LP3855 Typical Application

10.2.1 Design Requirements

DESIGN PARAMETERS

VALUE

Input voltage

3.3 V, ±10%

Output voltage

2.5 V, ±3%

Output current

1.5 A (maximum)

Input capacitor

10 µF (minimum)

Output capacitor

10 µF (minimum)

ERROR pullup resistor (LP3852 only)

10 k

Ω

10.2.2 Detailed Design Procedure

10.2.2.1 External Capacitors

Like any low dropout regulator, external capacitors are required to assure stability. These capacitors must be

correctly selected for proper performance.

10.2.2.1.1

Input Capacitor

An input capacitor of at least 10 µF is required. Ceramic or tantalum may be used, and capacitance may be

increased without limit.

14

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