QOD

(20ms)/(R

(22 F))

1.2V

10.8V e

u

P

u

19

TPS22810

www.ti.com

SLVSDH0B – DECEMBER 2016 – REVISED MAY 2017

Product Folder Links: TPS22810

Submit Documentation Feedback

Copyright © 2016–2017, Texas Instruments Incorporated

Typical Application (continued)

10.2.1 Design Requirements

For this design example, use the values listed in Table 4 as the design parameters:

Table 4. Design Parameters

DESIGN PARAMETER

EXAMPLE VALUE

12 V

Load current

2 A

22 µF

Desired fall time

20 ms

Maximum acceptable inrush current

400 mA

10.2.2 Detailed Design Procedure

10.2.2.1 Shutdown Sequencing During Unexpected Power Loss

Using the adjustable Quick Output Discharge function of the TPS22810, adding a load switch to each power rail

can be used to manage the power down sequencing in the event of an unexpected power loss (that is battery

removal). To determine the QOD values for each load switch, first confirm the power down order of the device

you wish to power sequence. Be sure to check if there are voltage or timing margins that must be maintained

load switch so that the load switches' fall times correspond to the order in which they need to be powered down.

In the above example, we must have this power rail's fall time to be 4 ms. Using Equation 2, we can determine

Equation 5.

(4)

(5)

resistance can be calculated as shown in Equation 6 and Equation 7.

(6)

(7)

Figure 22 through Figure 25 are scope shots demonstrating an example of the QOD functionality when power is

µF.