OUT

IN

GND

FAULT

ILIM

EN

External Logic

Signal & Driver

Power Pad

Output

Input

0.1 F

m

R

100 k

FAULT

W

C

0.1 F

RETRY

m

R

20 k

ILIM

W

CLOAD

RLOAD

TPS2553

Copyright © 2016, Texas Instruments Incorporated

OUT

IN

GND

FAULT

ILIM

EN

Input

Power Pad

Output

0.1 F

m

R

100 k

FAULT

W

C

0.1 F

RETRY

m

R

20 k

ILIM

W

CLOAD

RLOAD

TPS2553

Copyright © 2016, Texas Instruments Incorporated

21

TPS2552, TPS2553, TPS2552-1, TPS2553-1

www.ti.com

SLVS841F – NOVEMBER 2008 – REVISED AUGUST 2016

Product Folder Links: TPS2552 TPS2553 TPS2552-1 TPS2553-1

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Copyright © 2008–2016, Texas Instruments Incorporated

10.2.2 Auto-Retry Functionality

Some applications require that an overcurrent condition disables the part momentarily during a fault condition

and re-enables after a pre-set time. This auto-retry functionality can be implemented with an external resistor and

capacitor. During a fault condition, FAULT pulls low disabling the part. The part is disabled when EN is pulled

low, and FAULT goes high impedance allowing CRETRY to begin charging. The part re-enables when the voltage

on EN reaches the turnon threshold, and the auto-retry time is determined by the resistor-capacitor time

constant. The device continues to cycle in this manner until the fault condition is removed.

Figure 27. Auto-Retry Functionality

Some applications require auto-retry functionality and the ability to enable or disable with an external logic signal.

Figure 28 shows how an external logic signal can drive EN through RFAULT and maintain auto-retry functionality.

The resistor-capacitor time constant determines the auto-retry time-out period.

Figure 28. Auto-Retry Functionality With External EN Signal

10.2.2.1 Design Requirements

For this example, use the parameters shown in Table 3.

Table 3. Design Requirements

PARAMETER

VALUE

Input voltage

5 V

Output voltage

5 V

Current

1200 mA