TLE6262G Datasheet, PDF (7/38 Pages) Infineon Technologies AG – Fault Tolerant CAN - LDO

Final Data TLE 6262 G
CAN Transceiver
The TLE 6262 is optimized for low speed data transmission up to 125 kbaud in
automotive applications. Normally a differential signal is transmitted or received
respectively. When a bus wiring failure (see table 4) 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 bus failures are monitored via the diagnosis protocol of the SPI. Therefore it is
possible to distinguish 6 CAN bus failures or failure groups on the bits 8 to 13 (see table
3).
To reduce EMC caused by the transceiver 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 (bus-failure) the EMC
performance of the system is degraded from the differential mode.
The differential receiver threshold is set to typ. -2.8 V. This ensures correct reception in
the normal operation mode as well as in the failure cases 1, 2, 3a and 4 with a noise
margin as high as possible. When one of the bus failures 3, 5, 6, 6a, and 7 is detected,
the defective bus wire is disabled by switching off the affected bus termination and output
stage.
The CAN-transceiver offers three different operation modes that are controlled via the
SPI: the normal operation mode, Receive-only mode and V_bat stand-by mode. Please
see the state diagram (figure 3). In the V_bat stand-by mode the RTL output voltage is
switched to V_S.
In case of a wake-up via the bus lines or one of the bus lines respectively, the TLE 6262
automatically sets the RxD output LOW. To send respectively receive messages the
CAN-transceiver can now be set in normal operation mode or receive-only mode by the
microcontroller.
When a reset occurs the transceiver circuit is automatically switched to V_bat-stand-by
mode because the SPI input bits are automatically set LOW for this event.
A thermal shutdown of the CAN-transceiver circuit is monitored via the SPI diagnosis
bit 15.
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version: 2.03 date: 2002-03-20