TPS22933A

USB Port

DC Input

MSP430C3xx

µC

Switched

Load

Battery

USB

DC_IN

BAT

LOUT

EN

VOUT

GND

CAP

TPS22933A

USB Port

DC Input

Battery

USB

DC_IN

BAT

LOUT

EN

VOUT

GND

CAP

Power

Multiplexer

Output

TPS22933

www.ti.com

SLVSB34A – OCTOBER 2011 – REVISED JUNE 2015

9 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.

9.1 Application Information

9.1.1 LDO Capacitor (for CAP Pin)

An optional capacitor on the CAP pin helps stabilize the integrated LDO. Take care in capacitor sizing to reduce

inrush currents. The voltage on the CAP pin will follow the highest input. Since the max input voltage is 12 V, the

capacitor voltage rating must be higher than 12 V.

9.1.2 Using the CAP Pin as a Power Output

Figure 17 shows three power inputs multiplexed to source only through the CAP pin. In this case, the LDO

outputs are not used (EN is tied low). The highest of the inputs is chosen to drive the voltage at the CAP pin.

Figure 17. Using the CAP Pin as a Multiplexer Output

9.2 Typical Application

Figure 18 shows three power inputs multiplexed to source the LDO. The LDO always on output (LOUT) is tied to

an MSP430. The MSP430 then determines when to enable the switched output (VOUT) by driving the EN pin.

Figure 18. Application Example

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