C

= 1

F

IN

µ

GND

GND

LOAD

GND

V

OUT

V

IN

V

BATT

R

L

C

L

C

L

SMPS

(see Note A)

TPS22932B

ON1

ON2

ON3

TPS22932B

www.ti.com

SLVS802C – AUGUST 2009 – REVISED MAY 2015

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

10.1.1 ON and OFF Control

The ON pin controls the state of the switch. Activating ON continuously holds the switch in the on state so long

as there is no fault. ON is active HI and has a low threshold making it capable of interfacing with low voltage

signals. The ON pin is compatible with standard GPIO logic threshold. It can be used with any microcontroller

with 1.2-V, 1.8-V, 2.5-V, or 3.3-V GPIOs.

10.1.2 Input Capacitor

To limit the voltage drop on the input supply caused by transient in-rush currents when the switch turns on into a

discharged load capacitor or short-circuit, a capacitor must be placed between VIN and GND . A 1-μF ceramic

capacitor, CIN, placed close to the pins is usually sufficient. Higher values of CIN can be used to further reduce

the voltage drop during higher current application. When switching a heavy load, TI recommends to have an

input capacitor about 10 or more times higher than the output capacitor to avoid any supply drop.

10.1.3 Output Capacitor

Due to the integral body diode in the PMOS switch, a CIN greater than CL is highly recommended. A CL greater

than CIN can cause VOUT to exceed VIN when the system supply is removed. This could result in current flow

through the body diode from VOUT to VIN.

10.2 Typical Application

A.

Switched-mode power supply

Figure 39. Typical Application

10.2.1 Design Requirements

For this example, follow the design parameters listed in Table 3.

Table 3. Design Parameters

DESIGN PARAMETERS

EXAMPLE VALUE

VIN

3.3 V

CL

4.7 µF

Maximum Acceptable Inrush Current

150 mA

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