TLE7250X Datasheet, PDF (30/34 Pages) Infineon Technologies AG – High Speed CAN-Transceiver

TLE7250XLE
TLE7250XSJ
Application Information
8.3.2 Mode Change while the Bus Signal is “dominant”
The example in Figure 15 shows a mode change while the bus is “dominant” and the TxD input signal is set to
logical “high”.
While the transceiver TLE7250X is in receive-only mode the transmitter is turned off. The TLE7250X drives no
signal to the HS CAN bus. The normal-mode receiver is active in receive-only mode and the RxD indicates the
“dominant” signal on the HS CAN bus with a logical “low” output signal.
Changing the RM to logical “low” turns the mode of operation to normal-operating mode, while the TxD input
remains logical “high”. The transmitter remains disabled until the mode change is completed. The normal-mode
receiver remains active also during the mode change. In normal-operating mode the transmitter becomes active,
the bus remains “dominant” since the bus signal is driven from another HS CAN bus subscriber. The “dominant”
bus signal is indicated on the RxD output by a logical “low” signal.
Regardless which mode of operation is selected by the RM input pin, the RxD output indicates the signal on the
HS CAN bus. Also during the mode transition from receive-only mode to normal-operating mode or vice versa.
Note: The “dominant” signal on the HS CAN bus is set by another HS CAN bus
subscriber.
t = t_Mode
t = t_Mode
RM
t
TxD
t
V_DIFF
t
RxD
receive-only mode transition
normal-operating
transition
t
receive-only mode
normal-mode receiver and RxD output active
TxD input and transmitter blocked
TxD input and transmitter
active
TxD input and transmitter blocked
Figure 15 Example for a mode change while the HS CAN is “dominant”
Data Sheet
30
Rev. 1.0, 2015-08-12