OEM628 Technical Specifications
Appendix D
OEM6 Family Installation and Operation User Manual Rev 12
157
Figure 81: OEM628 LED Drive Buffer for ERROR and PV Signals Schematic
D.1.3
CAN Interface
The OEM628 provides two 2.7 V (3.3 V-compatible) CMOS level CAN controller ports. An external
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 provides ESD protection.
Figure 82: OEM628 CAN Transceiver Implementation Schematic
Only use a 120
Ω
termination resistor 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 (R101) value in
Figure 82, OEM628 CAN Transceiver Implementation
on page 157 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.
Table 33: CAN Critical Components
3V3
R101
1.0K
R100
270
D100
Green
Q100
MMBTA06
D
3V3
R103
1.0K
R102
270
D101
Red
Q101
MMBTA06
D
OEM628_PVALID
P1500, pin 10
OEM628_ERROR
P1500, pin 9
Designator
Manufacturer
Manufacturer Part Number
FB100, FB101
TDK
MMZ1005B800C
U100
Texas Instruments
SN74LVC1G86DCK
U101
Semtech
Bourns
OnSemi
LC03-6.TBT
CDNBS08-PLC03-6
LC03-6R2G
C101, C102
various
(22 pF 5% 50V COG 0603)
CAN1+
CAN1-
OEM628_CAN1RX
P1502, pin 10
OEM628_CAN1TX
P1502, pin 11
U100
TI SN65HVD231
3V3
R100
5.1K-1%
C100
0.1µF
R101
22.1K-1%
C102
22pF
R102
120
C101
22pF
120 ohm termination only
required if unit is on the
end of the CAN bus
(not all CAN devices
require termination)
FB100
FB101
U101
PLC03-6
IO1
GND1
GND2
IO2
IO4
GND4
GND3
IO3
1
2
3
4
8
7
6
5
D
D
D
D
D
D
D
1
4
8
2
3
5
7
6
D
R
RS
GND
VCC
VREF
CANH
CANL