Evaluation Board User Guide UG-330
Rev. 0 | Page 3 of 8
EVALUATION BOARD CONFIGURATION
SETTING UP THE EVALUATION BOARD
The E VA L-ADM3051EBZ allows the ADM3051 CAN
transceiver to be evaluated quickly and easily. The evaluation
board allows all of the input and output functions to be exercised
without the need for external components.
On the EVAL-ADM3051EBZ, the power is connected to VCC.
A 22 µF decoupling capacitor, C1, is fitted between VCC and
GND at the J1 board connector, and a 100 nF capacitor (C2 in
Figure 4) is fitted at the ADM3051 device. With the default 60 Ω
load installed, the typical supply current (I
CC
) is as follows:
• Recessive state: 5 mA
• Clock at 1 Mbps: 40 mA
• Clock at 250 kbps (slope control mode): 34 mA
In standby, with the bus in a recessive state, typical I
CC
is <1 mA.
OPERATING MODES
The LK3 jumper can be used to select the operating mode of the
ADM3051 device. One of three modes can be selected:
• Position A: standby mode
• Position B: high speed mode
• Position C: slope control mode
Standby Mode
Selecting Position A on LK3 connects Pin 8 (RS) of the
ADM3051 to VCC, placing the device in standby mode. This is
a low current mode where the driver is disabled. The receiver is
slower in standby mode.
High Speed Mode
Selecting Position B on LK3 connects Pin 8 (RS) of the
ADM3051 to GND, placing the device in high speed mode.
This allows operation at the maximum data rate (1 Mbps). Due
to fast transitions on the rising and falling edge of the output
signal, a shielded cable is generally required to control EMI.
Slope Control Mode
Selecting Position C on LK3 connects Pin 8 (RS) of the
ADM3051 to Resistor RS1 (default 47 kΩ installed). This places
the device in slope control mode, where the edges of the output
signal are controlled to reduce EMI. The maximum data rate
possible is reduced in this mode.
EVALUATION
An example operation of the EVAL-ADM3051EBZ is shown
in Figure 2. Ensure that LK3 is in Position B (high speed mode).
Connect a clock generator on TxD and set up a 500 kHz square
wave clock with output swing between 0 V and 5 V. Connect the
scope probes to the CANH and CANL test points. A plot of the
oscilloscope for TxD, RxD, CANH, and CANL is shown in
Figure 3. Channel 1 shows the TxD signal, Channel 4 shows the
RxD signal, and Channel 2 and Channel 3 show the CANH and
CANL signals, respectively.
10248-002
A B C
SIGNAL
GENERATOR
EVAL-ADM3051EBZ
TXD
INPUT
RXD
OUTPUT
TXD
RXD
VCC GND
GND
LK3
RS
OSCILLOSCOPE
CANH
VREF
CANL
5V POWER
SUPPLY
Figure 2. Basic ADM3051
CAN Transceiver Evaluation Board Operation
10248-003
CH1 2.00V CH2 2.00V
CH3 2.00V CH4 2.00V
M1.00ms A CH1 1.80V
4
2
1
T 50.00%
T
Figure 3. TxD, RxD, CANH, and CANL Signals (High Speed Mode)
