TLE6263 Datasheet, PDF (11/40 Pages) Infineon Technologies AG – LS CAN, LDO and HS Switch

Final Datasheet TLE 6263
Electromagnetic Emmision (EME)
To reduce radiated electromagnetic emission (EME), the dynamic slopes of the CANL
and CANH signals are both limited and symmetric. This allows the use of an unshielded
twisted or parallel pair of wires for the bus. During single-wire transmission (one of the
bus lines is affected by a bus line failure) the EME performance of the system is
degraded from the differential mode.
6.4 Bus Failure Management
There are 9 different CAN bus wiring failures defined by the ISO 11519-2/ISO 11898-3
standard. These failures are devided into 7 failure groups (see Table 2). The difference
between ISO11898-3 and ISO 11519-2 is also shown in Table 2. When a bus wiring
failure is detected the device automatically switches to a dedicated CANH or CANL
single-wire mode to maintain the communication if necessary. Therefore it is equipped
with one differential receiver and four single ended comparators (two for each bus line).
To avoid false triggering by external RF influences, the single wire modes are activated
after a certain delay time. As soon as the bus failure disappears the transceiver switches
back to differential mode after another time delay.
The differential receiver threshold is set to typ. -2.5V. This ensures correct reception in
the normal operation mode as well as in the failure cases 1, 2, 3a(6a) and 4(5) with a
noise margin as high as possible. When one of the bus failures 3(6), 5(4), 6(3), 6a(3a),
and 7 is detected, the defective bus wire is disabled by switching off the affected bus
termination and output stage. The failure cases in brackets() are the failure cases
according to ISO 11898-3. Simultaneously the multiplexing output of the receiver circuit
is switched to the unaffected single ended comparator
The bus failures are monitored via the diagnosis protocoll of the SPI. A general indication
of a CAN failure during normal mode at CANH or CANL is reported by OBIT 4 and 5. It
is also possible to distinguish 6 CAN bus failures or failure groups on the SPI output bits
3 to 7 in the RxOnly mode(see Table 2 and 5). The failures are reported until
transmission of the next CAN word begins.
In case the transmission data input TxD is permanently dominant, both, the CANH and
CANL transmitting stage are disabled after a certain delay time t_TxD. This is necessary
to prevent the bus from being blocked by a defective protocol unit or short to GND at the
TxD input.
In order to protect the transceiver output stages from being damaged by shorts on the
bus lines, current limiting circuits are integrated. The CANL and CANH output stage
respectively are protected by an additional temperature sensor, that disables them as
soon as the junction temperature exceeds the maximum value. In the temperature shut-
down condition of the CAN output stages receiving messages from the bus lines is still
possible.
Version 2.08
11
2004-06-07