VBATT: 2.7 V to 5.5 V

IN

OUT

GND

EN

For example,

1.5 V

1 PF

BATT

LP5952

Pre-

regulator

Li-Ion

or

3-cell

NiMh/NiCd

2.2 PF

For example, 1.2 V

A1

B2

C3

A3

C1

Load

0 to 350 mA

LP5952

SNVS469F – OCTOBER 2006 – REVISED DECEMBER 2015

www.ti.com

8 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.

8.1 Application Information

The LP5952 is designed to meet ultralow input-voltage application, by implementing VBATT as power supply of

this device. The VBATT is connected to the battery (range 2.5 V to 5.5 V), the VIN range can be 0.7 V to 4.5 V.

The device offers superior dropout and transient features combined with very low-quiescent currents. The

LP5952 delivers this performance in standard packages DSBGA and USON with an operating junction

temperature (TJ) of –40°C to +125°C.

8.2 Typical Application

8.2.1 Dual-Rail Linear Regulator

Figure 9. LP5952 Typical Application Circuit

8.2.1.1 Design Requirements

For typical dual-rail linear regulator parameters, see Table 1.

Table 1. Design Parameters

DESIGN PARAMETER

EXAMPLE VALUE

Input voltage range

0.7 V to 4.5 V

VBATT voltage range

2.7 V to 5.5 V

Output voltage

1.5 V

Output current

350 mA

Output capacitor range

2.2 µF

Input/output capacitor ESR range

3 m

Ω to 300 mΩ

8.2.1.2 Detailed Design Procedure

8.2.1.2.1

External Capacitors

As is common with most regulators, the LP5952 requires external capacitors to ensure stable operation. The

LP5952 is specifically designed for portable applications requiring minimum board space and the smallest size

components. These capacitors must be correctly selected for good performance.

8.2.1.2.2

Input Capacitor

If the LP5952 is used as a stand-alone device, an input capacitor at VIN is required for stability. It is

recommended that a 1-µF capacitor be connected between the LP5952 power voltage IN pin and ground. (This

capacitance value may be increased without limit).

12

Submit Documentation Feedback

Copyright © 2006–2015, Texas Instruments Incorporated

Product Folder Links: LP5952