TLE6251-2G_11 Datasheet, PDF (18/36 Pages) Infineon Technologies AG – High Speed CAN-Transceiver with Wake and Failure Detection

TLE6251-2G
Fail Safe Features
7.2
Local Failures
If a local failure occurs during the operation of the TLE6251-2G, the devices sets an internal local failure flag. The
local failure flag can be displayed to the microcontroller during the Receive-Only Mode and the failures are
indicated by a logical “Low” signal on the NERR pin. The following local failures can be detected:
• TxD time-out
• TxD to RxD Short
• RxD permanent Recessive Clamping
• Bus Dominant Clamping
• Over-Temperature Detection
7.2.1 TxD Time-Out Feature
The TxD time-out feature protects the CAN bus against permanent blocking in case the logical signal on the TxD
pin is continuously “Low”.
In Normal Operation mode, a logical “Low” signal on the TxD input pin for the time t > t_TXD enables the TxD time-
out feature and the TLE6251-2G disables the output stage. In Receive-Only mode the TLE6251-2G indicates the
TxD time-out by a logical “Low” signal on the NERR pin (see Figure 10). To release the output stage after the
permanent “Low” signal on the TxD input pin disappears, a mode change from Receive-Only mode to Normal
Operation mode is required.
CANH
CANL
t = t_TXD
TxD time–out
released
Output stage
released
t
TxD time-out
TxD
t
RxD
t
EN
t
NSTB
t
NERR
Normal Operation mode
Figure 10 TxD Time-Out Feature
Data Sheet
18
Receive-Only Normal Operation
mode
mode
Rev. 1.1, 2011-06-06