Data Sheet
68
Rev. 1.00
2017-07-31
TLE9262BQXV33
High Speed CAN Transceiver
FD tolerant mode is realized in the physical layer in combination with CAN Partial Networking. The TLE926x-
3QX variants of this family also support the CAN FD tolerant mode.
10.2.1
CAN OFF Mode
The CAN OFF Mode is the default mode after power-up of the SBC. It is available in all SBC Modes and is
intended to completely stop CAN activities or when CAN communication is not needed. The CANH/L bus
interface acts as a high impedance input with a very small leakage current. In CAN OFF Mode, a wake-up event
on the bus will be ignored.
10.2.2
CAN Normal Mode
The CAN Transceiver is enabled via SPI in SBC Normal Mode. CAN Normal Mode is designed for normal data
transmission/reception within the HS-CAN network. The Mode is available in SBC Normal Mode and in SBC
Stop Mode. The bus biasing is set to VCAN/2.
Transmission
The signal from the microcontroller is applied to the TXDCAN input of the SBC. The bus driver switches the
CANH/L output stages to transfer this input signal to the CAN bus lines.
Enabling sequence
The CAN transceiver requires an enabling time t
CAN,EN
before a message can be sent on the bus. This means
that the TXDCAN signal can only be pulled LOW after the enabling time. If this is not ensured, then the TXDCAN
needs to be set back to HIGH (=recessive) until the enabling time is completed.
Only the next dominant bit will be transmitted on the bus.
Figure 28
shows different scenarios and explanations for CAN enabling.
Figure 28 CAN Transceiver Enabling Sequence
Reduced Electromagnetic Emission
To reduce electromagnetic emissions (EME), the bus driver controls CANH/L slopes symmetrically.
Reception
Analog CAN bus signals are converted into digital signals at RXD via the differential input receiver.
t
V
CANDIFF
t
CAN,EN
t
V
TXDCAN
t
CAN
Mode
CAN
NORMAL
CAN
OFF
CAN,EN
t
recessive TXD level
required before start of
transmission
t
CAN, EN
not ensured , no
transmission on bus
CAN,EN
t
Correct sequence ,
Bus is enabled after t
CAN, EN
t
CAN, EN
not ensured ,
no transmission on bus
recessive TXD
level required
Dominant
Recessive
