mc33905s Freescale Semiconductor, Inc, mc33905s Datasheet - Page 46

• Manufacturer Part Number: mc33905s
• Description: System Basis Chip Gen2 With High Speed Can And Lin Interface
• Manufacturer: Freescale Semiconductor, Inc

interface. It consist in a low side driver between CANL and
gnd, and high side driver from CANH to 5V-CAN. Two
differential receivers are connected between CANH and
CANL, to detect bus state and to wake up from CAN Sleep
CAN INTERFACE SUPPLY
The CAN interface also has a supply pass from the battery
line, through the VSUP pin. This pass is used in CAN Sleep
Mode to allow wake-up detection.
the CAN interface current is sourced from the 5V-CAN pin.
During CAN Low Power Mode, the current is sourced from
the Vsup2 pin.
TX RX MODE
ON. In this mode, the CAN lines are controlled by the TXD pin
level, and the CAN bus state is reported on the RXD pin.
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33904/5
CAN INTERFACE
CAN INTERFACE DESCRIPTION
The figure below is a high level schematic of the CAN
The supply voltage for the CAN driver is the 5V-CAN pin.
During CAN communication (transmission and reception),
In Tx/Rx Mode, both the CAN driver and the receiver are
5V-CAN
RXD
TXD
SPI & State machine
SPI & State machine
5V-CAN
SPI & State machine
Figure 27. CAN Interface Block Diagram
CAN INTERFACE DESCRIPTION
CAN INTERFACE
2.5 V
Thermal
Failure Detection
& Management
Differential
Detection
Pattern
Receiver
Driver
Mode. An internal 2.5V reference provide the 2.5V recessive
level via the matched Rin resistors. The resistors can be
switched to gnd in CAN Sleep Mode. A dedicated split buffer
provide a low impedance 2.5V to the Split terminal, for
recessive level stabilization.
driver and receiver.The SPLIT pin is active and a 2.5V
biasing is provided on the SPLIT output pin.
RECEIVE ONLY MODE
CAN receiver active. In this mode, the device is only able to
report the CAN state on the RXD pin. The TXD pin has no
effect on CAN bus lines. The 5V-CAN regulator must be ON.
The SPLIT pin is active and a 2.5V biasing is provided on the
SPLIT output pin.
OPERATION in TX/RX Mode
Normal Mode and the TXD pin is recessive.
Driver
The 5V-CAN regulator must be ON. It supplies the CAN
This mode is used to disable the CAN driver, but leave the
The CAN driver will be enable as soon as the device is in
5V-CAN
VSUP
R
R
Wake-up
IN
IN
Receiver
QL
QH
Buffer
Analog Integrated Circuit Device Data
CANH
CANL
SPLIT
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