TLE6251G_08 Datasheet, PDF (10/32 Pages) Infineon Technologies AG – High Speed CAN-Transceiver with Wake Detection

TLE 6251 G
Reception
The analog CAN bus signals are converted into a digital signal at RxD via the differential input
receiver.
In normal mode and RxD only, the split pin is used to stabilize the recessive common mode
signal.
Permanent Recessive Clamping
If the RxD signal is permanent recessive, although there is a message sent on the bus, the host µC
of this transceiver could start a message at any time, because the bus seems to be idle. To prevent
this node to disturb the communication on the bus, the TLE 6251 G offers a so called permanent
RxD recessive clamping. If the RxD signal is permanent recessive, an error flag is set and the
transmitter is deactivated as long as the error occurs
Receive Only Mode (RxOnly Mode)
In the RxOnly mode, the transmission stage is deactivated but the reception of signals via the
CAN bus is still possible. This mode is implemented to support hardware and software diagnosis
functions.
If there is an hardware error on the transmission part of a node (e.g. bubbling idiot failure), in the
RxOnly mode, the bus is no longer blocked and the µC can still receive the messages on the bus.
It is also possible to make a network analysis of the interconnections between the nodes. A
connection between two nodes (in a network) is checked if both nodes are in the normal mode
and all others are in RxOnly mode. If a message from one node is sent to the other, this has to be
acknowledged. If there is no acknowledge of the message, the connection between the two nodes
has an error.
The RxD pin also works as an diagnosis flag, which is described more in detail in Table 2.
Final Data Sheet
10
Rev. 3.3, 2008-06-19