Evaluation Board User Guide

UG-317

Rev. 0 | Page 3 of 12

EVALUATION BOARD HARDWARE CONFIGURATION

TEST SETUP

The ADM2682E/ADM2687E evaluation board is shown

in Figure 2 with the default jumper settings on LK1 through

LK4 (driver and receiver enabled), power connection on J1,

input signal connection on J2, and probes attached to RXD,

TXD, Y, and Z for a loopback test (LK5 and LK6 are closed

to connect A to Y and B to Z).

JUMPER SETTINGS

The inputs to the ADM2682E/ADM2687E can be configured

using the jumpers on the evaluation board (see Table 1). Note

that multiple jumper blocks should not be placed on LK1 to

LK4 because the input sources may be shorted together. For

each link, a single jumper block can be moved from one posi-

tion to another, as specified in Table 1.

A

B

C

A

B

A

B

A

B

C

D

RXD

RE

DE

TXD

RXD

RXD

RE

DE

TXD

A

B

Z

Y

TXD

A

B

Z

Y

LK6

GND1

SHIELD

GND2

VCC

LK1

J3

J2

J1

J4

LK2

LK3

LK4

VISO

LK5

EVAL-ADM2682E_87EEBZ

OSCILLOSCOPE

SIGNAL

GENERATOR

3.3V OR 5V

POWER

SUPPLY

Figure 2. Basic Operation of the Evaluation Board for the ADM2682E/ADM2687E Isolated RS-485 Transceivers

Table 1. Jumper Configuration

Link

Connection

Description

LK1

A

Connects the receiver output (RxD) of the ADM2682E/ADM2687E to the J3 connector.

B

Connects the receiver output (RxD) of the ADM2682E/ADM2687E to the J8-1 terminal block connector.

LK2

A

Connects the receiver enable input (RE) of the

/

ADM2682E ADM2687E

B

Connects the receiver enable input (RE) of the

/

ADM2682E ADM2687E

C

Connects the receiver enable input (RE) of the

/

to the J8-2 terminal block connector.

ADM2682E ADM2687E

D

Connects the receiver enable input (RE) of the

/

to the driver enable input (DE); that is, the

input for both

ADM2682E ADM2687E

RE and DE is set by LK3. This setting ensures that when the driver is enabled, the receiver is

disabled, or when the driver is disabled, the receiver is enabled.

LK3

A

B

C

Connects the driver enable input (DE) of the ADM2682E/ADM2687E to the J8-3 terminal block connector.

LK4

A

Connects the driver input (TxD) of the ADM2682E/ADM2687E to the J8-4 terminal block connector.

B

Connects the driver input (TxD) of the ADM2682E/ADM2687E to the J2 connector.

LK5

Closed

Connects the ADM2682E/ADM2687E Receiver Input A to Driver Output Y. When LK5 and LK6 are both connected,

the evaluation board is configured for half-duplex operation.

Open

When LK5 and LK6 are both open, the evaluation board is configured for full-duplex operation.

LK6

Closed

Connects the ADM2682E/ADM2687E Receiver Input B to Driver Output Z. When LK5 and LK6 are both connected,

the evaluation board is configured for half-duplex operation.

Open

When LK5 and LK6 are both open, the evaluation board is configured for full-duplex operation.