IPS161H datasheet(13/25 Pages) STMICROELECTRONICS

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IPS161H

Protection and diagnostic

DocID029436 Rev 2

13/25

Protection and diagnostic

The IC integrates several protections to ease the design of a robust application.

6.1

Undervoltage lock-out

The device turns off if the supply voltage falls below the turn-off threshold (VUV(off)). Normal

operation restarts after VCC exceeds the turn-on threshold (VUV(on)). Turn-on and turn-off

thresholds are defined in Table 5: "Supply".

6.2

Overtemperature

The output stage turns off when its internal junction temperature (TJ) exceeds the shutdown

threshold TJSD. Normal operation restarts when TJ comes back below the reset threshold

(TJSD - TJHYST), see Table 9: "Protection and diagnostic". The internal fault signal is set

when the channel is off due to thermal protection and it is reset when the junction triggers

the reset threshold. This same behavior is reported on DIAG pin.

6.3

Cut-off

The output current of the power stage is internally limited at the fixed ILIM threshold.

The IPS161H implements the cut-off feature which limits the duration of the current

limitation condition.

The duration of the current limitation condition (Tcoff) can be set by a capacitor (CCoD)

placed between CoD and GND pins. The design rule for CCoD is:

tcoff[us] +/- 35% = 50 x Ccod[nF]

The drift of +/-35% is guaranteed in the range of 10 nF < Ccod < 100 nF; lower capacitance

than 10 nF can be used.

If ILIM threshold is triggered, the output stage remains in the current limitation condition

(IOUT = ILIM) no longer than tcoff. If tcoff elapses, the output stage turns off and restarts after

the tres restart time.

Thermal shutdown protection has higher priority than cut-off:



IC is forced off if TJSD is triggered before tcoff elapses



if TJSD is triggered, IC is maintained off even after the tres has elapsed and until the TJ

decreases below TJSD-TJHYST

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