UG-400 Datasheet, PDF (4/20 Pages) Analog Devices – Plug and play system evaluation

UG-400
Hardware User Guide
ISOLATED CAN
The isolated CAN port is implemented using the ADM3053 signal
and power isolated CAN transceiver. The ADM3053 connects
to CAN0 of the ADSP-BF548 and is capable of functioning at
data rates of up to 1 Mbit/sec. Figure 3 shows a circuit diagram
of the implementation of the ADM3053 on the ezLINX hardware.
The CAN node can be configured using Jumpers JP17 and JP18.
When both Jumpers JP17 and JP18 are fitted, the CAN node is
split terminated with 120 Ω and a common-mode capacitor of
47 nF. If termination is not required, remove JP17 and JP18. Table 4
shows the jumper configurations for all the interfaces on ezLINX.
The 5 V supply is connected to the VCC pin (Pin 8) to power the
isoPower isolated power supply of the ADM3053. This generates
an isolated 5 V on the VISOOUT pin (Pin 12) of the ADM3053 and
must be connected to the VISOIN pin (Pin 19). The 3.3 V supply
is connected to the VIO pin (Pin 6) to power the iCoupler signal
isolation of the ADM3053. This is to ensure compatibility with
the 3.3 V logic of the Blackfin ADSP-BF548. The RS pin (Pin 18)
is connected through a 0 Ω resistor to CAN_ISO_GND to
deactivate slew rate limiting.
A 4-pin screw terminal connector, J8, is used for easy access to the
CANH (Pin 1 of J8), CANL (Pin 3 of J8), and CAN_ISO_GND
(Pin 2 and Pin 4 of J8) signals.
The AN-1123 Application Note, Controller Area Network (CAN)
Implementation Guide, provides more information about imple-
menting CAN nodes.
The ADM3053 contains isoPower technology that uses high
frequency switching elements to transfer power through the
transformer. Special care must be taken during printed circuit
board (PCB) layout to meet emissions standards. Refer to the
AN-0971 Application Note, Recommendations for Control of
Radiated Emissions with isoPower Devices, for details on board
layout considerations.
CAN0TX
CAN0RX
3.3V 5V
U17
8
VCC
6
VIO
5
4 ^TxD
RxD
2
NC
1
3 ^GND1
7 ^GND1
9 ^GND1
10 ^GND1
GND1
ADM3053
CAN_ISO_5V
12
VISOOUT
19
VISOIN
17
CANH ₁₅
CANL
18
Rs ₁₄
VREF
11
GND2 ₁₃
GND2 ₁₆
GND2 ₂₀
GND2
JP18
JP17
R67
0R
R68 R69
60R4 60R4
J8
1
2
3
4
SCREW_4
GND
C165
47nF
CAN_ISO_GND CAN_ISO_GND CAN_ISO_GND CAN_ISO_GND
5V
3.3V
CAN_ISO_5V
C159 C163
10uF 0.1uF
C157 C158
0.1uF 0.01uF
C162 C161 C164 C160
10uF 0.1uF 0.1uF 0.01uF
GND
GND
CAN_ISO_GND
Figure 3. ADM3053 Isolated CAN Implementation
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