TPS22933 Datasheet, PDF (13/25 Pages) Texas Instruments – Triple-Input Power Multiplexer With Auto-Select and Low Drop-Out Voltage Regulator

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9 Application and Implementation
TPS22933
SLVSB34A – OCTOBER 2011 – REVISED JUNE 2015
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.
USB Port
DC Input
USB
LOUT
DC_IN
VOUT
TPS22933A _EN
BAT
Battery
GND
CAP
Power
Multiplexer
Output
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.
USB Port
DC Input
Battery
USB
LOUT
EN
DC_IN
TPS22933A
BAT
VOUT
GND
CAP
MSP430C3xx
µC
Switched
Load
Figure 18. Application Example
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