Datasheet

VIN
VOUT
R1/C1
ON/OFF
Q1
Q2
R1
C1
R2
COUT1
(2, 3)
R2
(1)
(5)
(6)
(4)
Module1
CIN
VDD1
Up to
8V
Input
VOUT
R1/C1
ON/OFF
Q1
Q2
R3
C1
R4
COUT2
(2, 3)
R2
(1)
(5)
(6)
(4)
Module2
VDD2
VIN
VOUT1
R1/C1
ON/OFF
Q1
Q2
R1
C1
R2
COUT1
(2, 3)
R2
(1)
(5)
(6)
(4)
Module1
(CPU/MCU)
CIN
VDD1
1.2 - 8V
Input
VOUT2
R1/C1
ON/OFF
Q1
Q2
R3
C2
R4
COUT2
(2, 3)
R2
(1)
(5)
(6)
(4)
Module2
VDD2
GPIO
TPS27081A
SLVSBE9D –APRIL 2012–REVISED APRIL 2013 www.ti.com
Multiple Modules Interdependent Power Supply Sequencing
Figure 8. Power Sequencing Using TPS27081A, Example 2
For system integrity reasons a certain power sequencing may be required among various modules. As shown in
Figure 8, Module 2 will power up only after Module 1 is powered up and the Module 1 GPIO output is enabled to
turn ON Module 2. TPS27081A when used as shown in Figure 8 will not only sequence the Module 2 power, but
also it will help prevent inrush current into the power path of Module 1 and 2.
Multiple Modules Interdependent Supply Sequencing without a GPIO Input
Figure 9. Power Sequencing using TPS27081A, Example 3
When a GPIO signal is not available connecting the ON/OFF pin of TPS27081 connected to Module 2 will power
up Module 2 after Module 1, when resistor R4 and capacitor C1 are chosen appropriately. The two TPS27081A
in this configuration will also control load inrush current.
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Product Folder Links: TPS27081A