XR31233 / XR31234 / XR31235 Evaluation Board User’s Manual
2/8
Hardware / System Setup
The EVB is factory installed with the CAN Bus transceiver
per Table 1.
CAN Bus Transceiver
Evaluation Board
XR31233
XR31233EDEVB
XR31234
XR31234EDEVB
XR31235
XR31235EDEVB
Table 1: Evaluation Board Part Numbers
Jumpers are factory installed per Table 2 to configure
the EVB for normal mode operation. Jumper and testing
options are described in the next section.
Header
Factory Setting
Description
E1
Jumper 1-5
RS = GND, high speed mode
E2
XR31233
XR31235
Jumper 4-5
LBK = 0 enables normal mode
AB = 0 enables normal mode
XR31234
Jumper 3-5
EN = 1 enables normal mode
J7
Jumper 1-2
Connects 120
Ω
between
CANH and CANL
J10
Jumper 1-2
Connects 120
Ω
between
CANH and CANL
Table 2: Factory Settings
Connect the CAN Bus, TTL/CMOS Driver Input and
Receiver Output per Table 3 and power and ground per
Table 4 for immediate operation.
Header
Connection
J5-2
TTL/CMOS Driver Input from CAN Controller
J8
CAN Bus
J11
TTL/CMOS Receiver Output to CAN Controller
Table 3: Input and Output Connections
J1
J!-1
J1-2
J1-3
J1-4
Name
GND
NC
V
CC
(!)
V
CC
(!)
NOTE:
1. V
CC
= 3.0V to 3.6V
Table 4: J1 Power and Ground Connections
Use probes summarized in Table 5 to observe operation at
various points. TP1, TP2 and TP3 provide GND for probes
at 3 different spots.
Header
Probe Point
J3
V
CC
into transceiver
J6
Driver input from CAN Controller to pin 1 (D)
J9
Differential CANH and CANL probe
J12
Receiver output from pin 4 (R) to CAN Controller
J14
VRxD (see next section).
Table 5: Monitoring Probes
Jumper and Testing Options
Power LED - J2
Connect Jumper J2 1-2 to illuminate the D1 LED when
power is connected if desired.
V
OD (D)
Under Maximum CAN Bus Load - J4 and J13
Connect J4, J13 and V
TEST
together to form the Figure 5
test circuit in the datasheet. The 330
Ω
resistors represent
the maximum resistance or load of N nodes in parallel
on the CAN Bus while measuring V
OD
and other device
performance.
Driver Input - J5 and J6
J5 allows for connecting pin 1 (D) of the transceiver under
test to one of the following:
■
■
Ground (dominant bus state),
■
■
V
CC
(recessive bus state)
■
■
An external input signal.
J6 is provided for probing as mentioned in Table 5.
Bus Termination - J7 and J10
As mentioned in the last section, J7 and J10 are factory
installed for bus termination between CANH and CANL. If
two EVBs are used, then connect J7 on one board and J10
on the other board for balanced termination.
Pin 8 (RS) Mode Selection - E1
Connect E1 in one of the following ways to configure pin 8
(RS):
■
■
1-5 to ground for high speed mode (factory
setting)
■
■
3-5 to pullup to V
CC
for lower power mode
■
■
4-5 to pulldown to ground for slope control mode
■
■
2-5 to pulldown to ground for slope control mode
with the TRIMPOT to adjust slope and speed.