UG121 Rev.0.00
Page 3 of 20
May 3, 2017
ISL71026MEVAL1Z
2. Functional Description
2.
Functional Description
The ISL71026MEVAL1Z evaluation board provides easy access to the pins of the ISL71026M IC and convenient
connectors/test points for connecting test equipment. The schematic, bill of materials, and top silkscreen for the board
are available in
“PCB Layout Guidelines” on page 11
“Typical Performance Curves” on page 15
shows performance data taken using the ISL71026MEVAL1Z evaluation
board and basic lab equipment.
In the following sections, we will discuss using the evaluation board.
2.1
Basic Layout of Evaluation Board
The basic layout of the evaluation board is described in the following sections. For more information, see
or the actual ISL71026MEVAL1Z evaluation board.
Located in the upper center of the board is the IS71026MVZ transceiver IC (U1). The evaluation board has a pin 1
dot, to show how the IC should be oriented onto the evaluation board. The IC pin 1 indicator dot needs to be
aligned with the evaluation board pin 1 dot indicator. The board comes with the IC soldered onto the board.
Power for the IC is located at the left side of the board through banana jacks labeled VCC and GND. A DC voltage
source of 3.3V must be connected between VCC and GND to power the part. Test points TP13 (VCC) and TP2
(GND) are available to measure the VCC voltage to the part.
Access to the D input to the transceiver is at the BNC connector labeled D at the upper right corner of the
evaluation board. You would connect the digital source of the CAN digital test pattern at this connector.
Access to the R output of the transceiver is at the test point labeled TP4 located at the top center of the evaluation
board. There is a through hole labeled R that could have a wire soldered to it, if you want to feed the digital output
into a CAN controller board.
Control of the RS pin is through jumpers J5, J6, J7, and J8 located at middle left side of the evaluation board. Only
one of these jumper locations should have a jumper installed at any one time. Putting the jumper at J5 will put the
transceiver in the listen mode. Putting the jumper at J6 will put the transceiver driver in the slow speed mode, at J7
in the medium speed mode, and at J8 in the fast speed mode. Note: J4 and R3 are not populated. They can be used
to put a mechanical potentiometer at the RS pin.
Access to the differential pins (CANH and CANL) are through the test points TP7 and TP8 or through the BNC
connectors labeled CANH and CANL (not populated) or through the D-SUB 9 pin male connector J1, located at
the bottom of the board. Use the J1 connector to connect two evaluation boards together for evaluating the
performance of two boards communicating with each other over various length cables. The CANH and CANL
BNCs can be used to apply voltages to the differential pins to evaluate the receiver of the transceiver.
The board comes populated with a 60Ω resistor (R9) installed across the CANH and CANL lines. Many
performance tests for the transceiver such as propagation delay, rise time, fall time, and skew are done with a 60Ω
resistor. In a normal CAN system the bus is terminated at both ends with a 120Ω resistor, which gives a differential
loading of 60Ω.
See the board schematic (
) for the reference designators of the jumpers, resistors and
connectors associated with each I/O.
2.2
Power Supply
The ISL71026M IC requires a DC power supply in the range of 3.0V to 3.6V for proper operation.
The power supply is connected at banana jacks VCC and GND. The power supply should be capable of delivering
100mA of current.
2.3
Evaluation Board Logic Control
The ISL71026M IC has three logic control input pins; the D (pin 1), RS (pin 8), and LBK (pin 5).
Summary of Contents for ISL71026MEVAL1Z
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