Quick Start

Required Equipment

Before beginning, the following equipment is needed:

•

One +5V 550mA current-limited power supply with

a built-in current meter

•

One voltmeter

•

One logic signal generator

•

One oscilloscope with a differential probe

Procedure

The MAX13487E EV kit is fully assembled and tested.

Follow the steps below to verify board operation.

Caution: Do not turn on the power supply until all

connections are completed.

1) Connect a voltmeter to the VOUT and GND PC pads.

2) Verify that a shunt is not installed across the pins of

jumper JU1 (U2 enabled).

3) Verify that a shunt is installed across pins 1-2 of

jumper JU2 (U1 enabled).

4) Verify that a shunt is installed across the pins of

jumpers JU3 (AutoDirection enabled), JU4 (pull-

down), JU6 (pullup), and JU5 (bus terminated).

5) Connect the +5V power supply to the VIN pad.

Connect the power supply’s ground to the PGND pad.

6) Turn on the power supply and verify that the volt-

meter at VOUT reads +5V.

7) Using the logic signal generator, apply a +5V logic

signal to the TXD PCB pad and PGND.

8) Using the oscilloscope and differential probes, verify

the signal at the A-B pads (isolated side).

Note: The +5V supply powering the MAX13487E EV kit

must be current-limited at 550mA and the output load

current for the output should be limited to less than

300mA.

Detailed Description of Hardware

The EV kit features a MAX13487E IC in an 8-pin SO sur-

face-mount package and demonstrates the ESD-

protected MAX13487E RS-485/RS-422 AutoDirection

transceiver. The differential driver and receiver are con-

figured for half-duplex operation and communicate up

to 500kbps. The transceiver circuit is a 1/4-unit load on

the receiver’s bus.

The EV kit features PCB pads to ease interfacing with

the driver/receiver logic signals on the non-isolated side

using the TXD, RXD, and PGND pads, respectively. The

MAX13487E IC is powered from the isolated VOUT

supply. Photocoupler U4 provides isolation for the

receiver’s RO signal (RXD pad) and U5 provides isola-

tion for the data-in DI signal (TXD pad).

The EV kit demonstrates the MAX13487E slew-rate

limited driver, which minimizes EMI radiation.

Photocouplers U4 and U5 are rated for up to 15Mbps.

The MAX13487E receiver signal is provided at the RO

pin. The RO pin will give a logic-high if A-B > +200mV.

A logic-low is given if A-B < -200mV. Refer to the

Transmitting and Receiving sections in the Function

Tables in the MAX13487E/MAX13488E IC data sheet

for additional information on the AutoDirection circuitry

operation. Also see the

AutoDirection and Receiver

Enable Selection section in this document for configur-

ing the AutoDirection and receiver operation.

MAX13487E Evaluation Kit

2

_______________________________________________________________________________________

Component Suppliers

Note: Indicate that you are using the MAX13487E or

MAX13488E when contacting these component suppliers.

*

EP = Exposed pad.

Component List (continued)

DESIGNATION

QTY

DESCRIPTION

U2

1

Integrated primary-side controller

and H-bridge driver (8 SO-EP*)

Maxim MAX256ASA+

U3

1

Linear regulator (8 SO)

Maxim MAX1659ESA+

U4, U5

2

15Mbps CMOS photocouplers

(5 SO)

CEL/NEC PS9151-A

—

6

Shunts (JU1–JU6)

—

4

Rubber bumpers

—

1

PCB: MAX13487E Evaluation Kit#

SUPPLIER

PHONE

WEBSITE

CEL/NEC

(California Eastern

Laboratories/NEC)

408-588-2247 www.cel.com

Central

Semiconductor

Corp.

631-435-1110 www.centralsemi.com

Diodes, Inc.

805-446-4800 www.diodes.com

HALO Electronics,

Inc.

650-903-3800 www.haloelectronics.com

Murata

Electronics North

America, Inc.

770-436-1300

www.murata-

northamerica.com