TLE6254-3G_07 Datasheet, PDF (10/26 Pages) Infineon Technologies AG – Fault Tolerant Low Speed CAN-Transceiver

TLE6254-3G
If either of the supply voltages drops below the specified limits, the transceiver is
automatically switched to V_BAT stand-by mode or power down mode respectively.
Table 2
Truth Table of the CAN Transceiver
NSTB ENT Mode
INH
NERR
RxD
RTL
0
0
V_BAT stand-by V_BAT
active LOW wake-up interrupt if switched
mode¹⁾
V_CC is present
to V_BAT
0
0
sleep mode²⁾ floating
switched
to V_BAT
0
1 go to sleep becomes
switched
command floating
to V_BAT
1
0
Receive-only V_BAT
active LOW HIGH = recessive switched
mode
V_BAT power-on receive data;
to V_CC
flag³⁾
LOW = dominant
receive data
1
1
normal mode V_BAT
active LOW HIGH = recessive switched
bus error flag receive data;
to V_CC
LOW = dominant
receive data
1) Wake-up interrupts are released when entering normal operation mode.
2) If go to sleep command was used before, ENT may turn LOW as V_CC drops, without affecting internal
functions.
3) V_BAT power-on flag will be reseted when entering normal operation mode.
Bus Failure Management
The TLE6254-3G detects the bus failures as described in Table 3, and automatically
switches to a dedicated CANH or CANL single wire mode to maintain data transmission
if necessary. Therefore, the device is equipped with one differential receiver and 4 single
ended receivers, two for each bus line. To avoid false triggering by external RF
influences the single wire modes are only activated after a certain delay time. As soon
as the bus failure disappears the transceiver switches back to differential mode after
another time delay. Bus failures are indicated in the normal operation mode by setting
the NERR output low.
The differential receiver threshold is typ. -3.1 V. This ensures correct reception in the
normal operation mode as well as in the failure cases 1, 2 and 4 with a noise margin as
high as possible. For these failures, further failure management is not necessary.
Detection of the failure cases 1, 2, 3a and 4 is only possible when the bus is dominant.
Nevertheless, they are reported on the NERR output until transmission of the next CAN
word on the bus begins.
Data Sheet
10
Rev. 2.1, 2007-08-09