TLE8263-2E Datasheet, PDF (34/94 Pages) Infineon Technologies AG – Universal System Basis Chip

TLE8263-2E
Confidential
High Speed CAN Transceiver
Failure
Overtemp
ON
Overtemperature
OFF
t
TxD_CAN
VC C1 µC
GND
V_diff
D
Recessive
Figure 13 Release of the Transmission after Overtemperature
t
R
Dominant
t
8.4.5 Permanent RxD Recessive Clamping
If the RxD signal is permanently recessive (such as shorted to V_cc1µC), although there is a message sent on the
bus, the host microcontroller of this transceiver could start a message at any time because the bus appears to be
idle. To prevent this node from disturbing communication on the bus, the SBC offers permanent RxD recessive
clamping. If the RxD signal is permanently recessive, the failure is diagnosed and the transmitter is deactivated
as long as the error occurs. The transmitter is reactivated after an SPI command.
8.4.6
V_ccHSCAN Undervoltage
The CAN transceiver cell has no dedicated under voltage detection and use the V_CC2 or V_CC3 under voltage
circuitry. The µC can switch of the CAN in case of undervoltage.
8.4.7 Bus failures
In case one of the following bus failures is detected by the SBC the interrupt bit CAN BUS is set to “1” and an
interrupt is generated, if not masked. The CAN transceiver does not change the mode due to a detected bus
failure.
Bus Failures
• CANH short to GND
• CANH short to Vs
• CANH short to Vcc
• CANL short to GND
• CANL short to Vs
• CANL short to Vcc
A short of CANH to CANL is detected by the microcontroller as the signal sent on TxD is not received on RxD.
8.5
SPLIT Circuit
SPLIT circuitry is activated during CAN Normal and Receive Only Mode and de-activated (SPLIT pin high ohmic)
during CAN Wake Capable and OFF Modes. The SPLIT pin is used to stabilize the recessive common mode signal
in Normal Mode and RxD Only Mode. This is achieved with a stabilized voltage of 0.5 x V_ccHSCAN typical at SPLIT.
A correct application of the SPLIT pin is shown in Figure 14. The SPLIT termination for the left and right nodes is
implemented with two 60 Ω resistors and one 10 nF capacitor. The center node in this example is a stub node and
the recommended value for the split resistances is 1.5 kΩ.
Data Sheet
34
Rev. 1.0, 2009-03-31