CAN Controller Ports

OEM7 receivers provide 3.3 V CMOS-level CAN controller ports. An external CAN transceiver is required. The following figure shows a typical CAN transceiver implementation.

The combination of ferrite beads and small-value capacitors are not necessarily required but may provide improved EMI performance. A low-capacitance TVS device is shown on the schematic to provide ESD protection.

CAN Transceiver Pin Designation

	OEM719	OEM729	OEM7600	OEM7700	OEM7720
Connector	P17011 Pins 6 and 7 are multiplexed with other signals and may not be available when certain features are enabled. See OEM719 Interface Connector for more information.	P1803	P1701	P2001	P1901
CAN1TX	7	10	36	36	36
CAN1RX	6	11	38	38	38
CAN2TX	20	12	37	37	37
CAN2RX	8	13	35	35	35

The 120Ω termination resistor should only be used when the CAN device is used at one end of the CAN bus. Multiple terminations along the length of the CAN bus will degrade performance for all CAN devices on that bus.

The slew rate adjustment resistor (R2) value shown sets the slew rate for applications for SAE J1939 agricultural applications. Other applications may require a different slew rate. Refer to the transceiver data sheet for more information.

CAN Transceiver Example Bill of Materials (critical components)

Designator	Manufacturer	Manufacturer Part Number
FB1, FB2	TDK	MMZ1005B800C
U1	Texas Instruments	SN65HVD231QD
U2	Bourns	CDNBS08-PLC03-6