L9800 datasheet(34/55 Pages) STMICROELECTRONICS

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Protection functions

8.1

Overload protection

The L9800 has two different overload current thresholds that preserve itself in case of overload or short-circuit of

the load (see Figure 24):

•

IL(OVL0) between channel switch on and tOVLIN

•

IL(OVL1) after tOVLIN

Every time the channel is switched off the over load current threshold is set back to IL(OVL0).

Figure 24. Overload thresholds

GADG071120230941GT

OUTn driving

signal

IL(OVL)

IL(OVL0)

IL(OVL1)

tOVLIN

In case the load current is higher than IL(OVL0) or IL(OVL1), after time tOFF(OVL) the over loaded channel is switched

off and the corresponding diagnosis bit DIAG_OVC_OVT.OUTn is set to “1”. The channel can be switched on

after clearing the protection latch by setting the corresponding DIAG_OVC_OVT_RLW.OUTn bit to “1”. This bit is

set back to “0” internally after de-latching the channel. Please refer to Figure 25 for details.

Figure 25. Latch-off overload

GADG071120230946GT

OUTn driving

signal

IL(OVL1)

DIAG_OVC_OVT.OUTn

DIAG_OVC_OVT_RLW.OUTn

tOFF(OVL)

L9800

Protection functions

DS14041 - Rev 2

page 34/55

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