General Description

The MAX5427 evaluation kit (EV kit) is a fully assembled
and tested surface-mount circuit board that evaluates
the MAX5427 digital potentiometer. Included software
generates the required signals for one-time-programma-
ble operation and allows easy control of the wiper posi-
tion. An on-board 8-pin µMAX socket eases replacement
of the device. The EV kit is designed to be connected to
a standard IBM-compatible PC-parallel (printer) port.

Windows

95/98/2000-compatible software provides a

user-friendly interface to exercise the MAX5427's fea-
tures. The program is menu driven and offers a graphic
user interface with control buttons. (Note: Windows 2000
requires the installation of a driver; refer to Win2000.pdf
or Win2000.txt located on the diskette for information.)

This EV kit can also be used to evaluate the MAX5428
and MAX5429 digital potentiometers.

Windows is a registered trademark of Microsoft Corp.

Features

o On-Board 8-Pin µMAX Socket
o Windows 95/98/2000 Evaluation Software
o Software Adjusts and Programs Wiper Position
o Fully Assembled and Tested

Evaluates: MAX5427/MAX5428/MAX5429

MAX5427 Evaluation Kit

________________________________________________________________ Maxim Integrated Products

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642,or visit Maxim's website at www.maxim-ic.com.

19-2475; Rev 0; 5/02

Ordering Information

Component List

PART

TEMP RANGE

IC PACKAGE

MAX5427EVKIT

0°C to +70°C

8 µMAX

DESIGNATION

QTY

DESCRIPTION

4.7µF ±20%, X5R 6.3V
ceramic capacitor (0805)
TDK C2012X5R0J475M

22µF ±20%, X5R 16V ceramic
capacitor (1812)
TDK C4532X7R1C226M

Green surface-mount LED

Dual Shottky diode (SOT23)
Diodes INC BAT54C or
Fairchild BAT54C or
General Semiconductor or
BAT54C

DB-25 right-angle plug (male)

1.6k

±5% resistor (1206)

8-pin µMAX socket
Wells-CTI 656-1082211

DESIGNATION

QTY

DESCRIPTION

Digital potentiometer
(8-pin µMAX)
MAX5427EUA

Low-voltage, analog switch (6-
pin SOT23)
MAX4544EUT

Low-voltage level translator
(10-pin µMAX)
MAX1840EUB

None

MAX5427 PC board

None

3 1/2in software disk
MAX5427 evaluation kit

None

MAX5427 data sheet

None

MAX5427 EV kit data sheet

Note: To evaluate the MAX5428 or the MAX5429, request a
free sample of MAX5428EUA or MAX5429EUA with the
MAX5427EVKIT.

Evaluates: MAX5427/MAX5428/MAX5429

MAX5427 Evaluation Kit

_______________________________________________________________________________________

Quick Start

Recommended Equipment

· One variable DC power supply capable of supply-

ing between 2.7V and 5.5V at 100mA

· One fixed DC power supply capable of supplying

11V at 20mA

· One

ohmmeter

· A parallel printer port (this is a 25-pin socket on the

back of the computer)

· A computer running Windows 95, 98, or 2000.

(Note: Windows 2000 requires the installation of a
driver; refer to Win2000.pdf or Win2000.txt located
on the diskette for information.)

· A standard 25-pin, straight-through, male-to-female

cable (printer extension cable) to connect the com-
puter's parallel port to the MAX5427EVKIT

Procedure

The MAX5427 EV kit is fully assembled and tested. Follow
the steps below to verify board operation. Do not turn on
the power supply until all connections are completed:

1) Connect a cable from the computer's parallel port

to the MAX5427EVKIT. To avoid damaging the EV
kit or your computer, do not use a 25-pin SCSI port
or any other connector that is physically similar to
the 25-pin parallel printer port. The parallel port is
typically labeled LPT or PRINTER.

2) Adjust the variable power supply to 5V.

3) Ensure that the variable power supply is turned off.

4) Ensure that the fixed 11V power supply is turned

off.

5) Connect the positive terminal of the variable power

supply to the pad labeled VDD.

6) Connect the ground return of the variable power

supply to the corresponding pad labeled GND.

7) Connect the positive terminal of the fixed 11V power

supply to the pad labeled VPP.

8) Connect the ground return of the fixed 11V power

supply to the corresponding pad labeled GND.

9) Connect the positive terminal of the ohmmeter to

the pad marked H.

10) Connect the ground return of the ohmmeter to the

pad marked W.

11) Install the software by running the INSTALL.EXE

program. The install program copies the files and
creates icons for them in the Windows 95/98/2000
Start menu.

12) Turn on the 5V variable power supply.

13) Turn on the 11V fixed power supply.

14) Start the MAX5427 program by opening its icon in

the Start menu.

15) Wait until the program automatically detects the

MAX5427 and displays the main window (Figure 1).
The MAX5427 is now in its default power-on-reset
(POR) mode (wiper is at midscale for an unpro-
grammed device).

Detailed Description

of Software

Use the mouse or press the Tab key to navigate with the
arrow keys. Each of the buttons corresponds to com-
mands used to set the wiper position or program the
device. Note: Words in boldface indicate user-selectable
features in the software.

Wiper Control

The wiper position is adjusted sequentially through the
tap positions using a simple 2-wire interface. To incre-
ment the wiper position, press the Up button. To decre-
ment the wiper position, press the Down button.

SUPPLIER

PHONE

FAX

WEBSITE

Diodes Inc.

805-446-4800

805-446-4850

www.diodes.com

Fairchild Semiconductor

888-522-5372

N/A

www.fairchildsemi.com

General Semiconductor

760-804-9258

760-804-9259

www.gensemi.com

TDK

847-803-6100

847-390-4405

www.component.tdk.com

Wells-CTI

623-581-5330

623-780-3987

www.wellscti.com

Component Suppliers

Note: Please indicate that you are using the MAX5427 when contacting these component suppliers.

Evaluates: MAX5427/MAX5428/MAX5429

MAX5427 Evaluation Kit

_______________________________________________________________________________________

Program Control

To set the power-on position of the wiper, press the
Program button. Checking the Disable Interface
checkbox disables the 2-wire interface, preventing fur-
ther unwanted adjustment. Refer to the One-Time
Programming section of the MAX5427/MAX5428/
MAX5429 data sheet for more details.

Resetting the MAX5427

The Disable Parallel Port checkbox is used to reset
the digital potentiometer at power-up. Checking this
box forces all of the parallel port lines to a logic low
(0V), ensuring that the device is not powered through
the interface. To reset the device, do the following:

1) Turn off the power supply connected to VPP.

2) Turn off the power supply connected to VDD.

3) Check the Disable Parallel Port checkbox.

4) Disconnect any power supply connected to the H,

W, and L pads.

5) Turn on the power supply connected to VDD.

6) Turn on the power supply connected to VPP.

7) Uncheck the Disable Parallel Port checkbox.

Detailed Description

of Hardware

The MAX5427 EV kit is a complete programming plat-
form for the MAX5427 digital potentiometer. Parallel
port signals are level translated through a MAX1840 to
ensure reliable operation. The EV kit also includes an
8-pin µMAX socket to ease the programming of multiple
devices.

Figure 1. MAX5427 EV Kit Software Main Window

NOTE: THE MAIN WINDOW OF THE MAX5427 EV KIT SOFTWARE ALLOWS THE USER TO EASILY ADJUST AND PROGRAM THE MAX5427.

Evaluates: MAX5427/MAX5428/MAX5429

MAX5427 Evaluation Kit

_______________________________________________________________________________________

Figure 2. MAX5427 EV Kit Schematic

MAX1840

MAX5427

DATA

I/O

4.7

µF

CLK

RST

GND

N.C.

U/D

VDD

GND

µF

VDD

J1-4

CIN

J1-5

RIN

J1-13

J1-8

J1-2

J1-3

J1-1

J1-9

J114

J1-10

J1-11

J1-12

J1-15

J1-18

J1-19

J1-20

J1-21

J1-22

J1-23

J1-24

J1-25

N.C.

J117

J116

SHDN

J1-6

J1-7

VPP

GND

VDD

MAX4544

COM

V+

NOTE: U1 IS A SOCKETED 8-PIN

µMAX.

WELLS-CTI PART NO. 656-1082211.

CONNECTOR DB-25

GND

1.6k

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________ 5

Printed USA

is a registered trademark of Maxim Integrated Products.

Evaluates: MAX5427/MAX5428/MAX5429

MAX5427 Evaluation Kit

1.0"

Figure 3. MAX5427 EV Kit Component Placement Guide--
Component Side

1.0"

Figure 4. MAX5427 EV Kit PC Board Layout--Component Side

Figure 5. MAX5427 EV Kit PC Board Layout--Solder Side

1.0"

Part Number MAX5427EVKIT