TLE9255WLC datasheet(31/100 Pages) INFINEON

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Data Sheet

Rev. 1.02 2018-02-02

TLE9255W

Fail Safe Functions

6.1

Short Circuit Protection

The CANH and CANL bus pins are proven to cope with a short circuit fault to GND and to the supply voltages.

A current limiting circuit protects the transceiver from damage.

6.2

Undervoltage detection

The TLE9255W has independent undervoltage detection on VBAT, VCC and VIO. Undervoltage events at these

pins may have impact on the functionality of the device and also may change the mode of operation.

6.2.1

Undervoltage detection on VBAT

If the power supply VBAT < VBAT_UV for more than the glitch filter time tVBAT_filter, then an undervoltage is detected.

On detection of undervoltage the TLE9255W performs the following actions:

• disable Local wake-up

• Set the bit VBAT_UV in the SPI register TRANS_UV_STAT to “1”. After the completion of a Power on Reset

or after a transition from Sleep Mode to Stand-by Mode the VBAT supply stabilization period must be

completed before an undervoltage notification can be recorded in the VBAT_UV bit. The undervoltage

notification is only possible once the VBAT supply has exceeded the threshold VBAT_UV, that is VBAT > VBAT_UV.

Figure 25 shows this scenario.

Only an SPI command can reset the undervoltage bit VBAT_UV (see Chapter 8.2). The glitch filter is

implemented in order to prevent an undervoltage detection due to short voltage transients on VBAT. Figure 24

shows the effect of glitch filter time in different undervoltage scenarios.

Figure 24

Undervoltage detection VBAT

VIO and VCC are within the functional range

VBAT

„0"

VBAT_UV

tVBAT_filter

Status Bit:

VBAT_UV

tVBAT_filter

„1"

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