SS/TR

STSEL

AGND

CSS

(Optional)

22

TPS84A20

SLVSBC6C – MARCH 2013 – REVISED DECEMBER 2019

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10.17 Slow Start (SS/TR)

Connecting the STSEL pin to AGND and leaving SS/TR pin open enables the internal SS capacitor with a slow

start interval of approximately 1.2 ms. Adding additional capacitance between the SS pin and AGND increases

the slow start time. Increasing the slow start time reduces inrush current. Table 8 shows an additional SS

capacitor connected to the SS/TR pin and the STSEL pin connected to AGND. See Table 8 for SS capacitor

values and timing interval.

Figure 32. Slow-Start Capacitor (CSS) and STSEL Connection

Table 8. Slow-Start Capacitor Values and Slow-Start Time

CSS (nF)

OPEN

3.3

4.7

10

15

22

33

SS Time (msec)

1.2

2.1

2.5

3.8

5.1

7.0

9.8