Phytec phyCORE-PXA270, Hardware Manual

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CAN Interface
11 CAN Interface
An industry-standard CAN interface is populated on the PXA270
Carrier Board for integration into networked machines and systems.
The CAN controller (SJA1000) is located on the phyCORE module.
OUT
FF-UART
CAN
USB
HOST
USB
Client Ethernet
POWER
BT-UART
IN MIC
A
B
TOUCH
Figure 30: CAN Connector
The signals CAN-RxD and CAN-TxD are optically isolated from the
phyCORE module over an ADU1402 opto-coupler (U45) and are
converted to CANH and CANL using an 82C251 CAN transceiver
(U46). A switching voltage regulator converts the exernal CAN
supply voltage in a range from 8 – 24 V to a 5 V/0.5 A CANVCC.
This enables galvanic separation of the CAN circuitry from the
potential of the Carrier Board. Jumpers JP7 and JP10 must be closed
at position 2+3 in order to support galvanic separation, when closed at
position 1+2 the CAN interface is powered by the internal 5 V supply
from the Carrier Board.
Jumper Default Comment
JP7 This jumper configures the CAN circuitry supply
voltage.
1 + 2 X CAN supply voltage derived from on-board supply
voltage
CAN supply voltage from external source for optical
isolation
2 + 3 -
JP10 This jumper configures the CAN circuitry supply
voltage.
1 + 2 X CAN Ground from external source for optical isolation.
2 + 3 - CAN Ground connected to on-board Ground potential.
Table 44: CAN Interface Jumper Configuration
©
PHYTEC Meßtechnik GmbH 2006 L-668e_1
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