VIPER26

Automatic auto restart after overload or short-circuit

Doc ID 17736 Rev 2

17/25

14

Automatic auto restart after overload or short-circuit

The overload protection is implemented in automatic way using the integrated up-down

counter. Every cycle, it is incremented or decremented depending if the current logic detects

Table 8 on page 7 or the one set by the user through the R

Figure 13 on page 9.

see the

Figure 26 on page 17 and the mentioned time values on Table 8 on page 7.

In case of overload or short-circuit event, the power MOSFET switching will be stopped after

protection will occur in the same way until the overload condition is removed, see

Figure 26

on page 17.

This protection ensures restart attempts of the converter with low repetition rate, so that it

works safely with extremely low power throughput and avoiding the IC overheating in case of

repeated overload events.

If the overload is removed before the protection tripping, the counter will be decremented

cycle by cycle down to zero and the IC will not be stopped.

Figure 26.

Timing diagram: OLP sequence

time

time

V

DD

V

DDon

V

DDCSon

I

DRAIN

I

Dlim_bm

t

1

*

* The time t

t

RESTART

t

SS

t

OVL

t

RESTART

t

SS

t

OVL

t

RESTART

t

SS

SHORT CIRCUIT

OCCURS HERE

SHORT CIRCUIT

REMOVED HERE