General Description

The MAX5477/MAX5478/MAX5479 nonvolatile, dual,

linear-taper, digital potentiometers perform the function

of a mechanical potentiometer, but replace the

mechanics with a simple 2-wire digital interface. Each

device performs the same function as a discrete poten-

tiometer or variable resistor and has 256 tap points.

The devices feature an internal, nonvolatile EEPROM

used to store the wiper position for initialization during

power-up. A write-protect feature prevents accidental

ble serial interface allows communication at data rates

up to 400kbps, minimizing board space and reducing

interconnection complexity in many applications. Three

address inputs allow a total of eight unique address

combinations.

The MAX5477/MAX5478/MAX5479 provide three nomi-

nal resistance values: 10k

Ω (MAX5477), 50kΩ

(MAX5478), or 100k

Ω (MAX5479). The nominal resistor

temperature coefficient is 35ppm/°C end-to-end and

5ppm/°C ratiometric. The low temperature coefficient

makes the devices ideal for applications requiring a low-

temperature-coefficient variable resistor, such as low-

drift, programmable gain-amplifier circuit configurations.

The MAX5477/MAX5478/MAX5479 are available in 16-

pin 3mm x 3mm x 0.8mm thin QFN and 14-pin 4.4mm x

5mm TSSOP packages. These devices operate over

the extended -40°C to +85°C temperature range.

Applications

Mechanical Potentiometer Replacement

Low-Drift Programmable-Gain Amplifiers

Volume Control

Liquid-Crystal Display (LCD) Contrast Control

Features

♦ Power-On Recall of Wiper Position from

Nonvolatile Memory

♦ EEPROM Write Protection

♦ Tiny 3mm x 3mm x 0.8mm Thin QFN Package

♦ 35ppm/°C End-to-End Resistance Temperature

Coefficient

♦ 5ppm/°C Ratiometric Temperature Coefficient

♦ 1µA (max) Static Supply Current

♦ Single-Supply Operation: +2.7V to +5.25V

♦ 256 Tap Positions per Potentiometer

♦ ±0.5 LSB DNL in Voltage-Divider Mode

♦ ±1 LSB INL in Voltage-Divider Mode

Digital Potentiometers

________________________________________________________________ Maxim Integrated Products

1

MAX5477

MAX5478

MAX5479

8-BIT

SHIFT

REGISTER

POR

16-BIT

LATCH

16-BIT

NV

MEMORY

SDA

SCL

WP

A0

A1

A2

8

256

POSITION

DECODER

8

8

256

256

POSITION

DECODER

256

HA

WA

LA

HB

WB

LB

GND

I

INTERFACE

Ordering Information/Selector Guide

Functional Diagram

19-3379; Rev 2; 12/04

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.

Pin Configurations appear at end of data sheet.

Products, Inc. or one of its sublicensed Associated

defined by Philips.

PART

TEMP RANGE

PIN-PACKAGE

END-TO-END

RESISTANCE (k

Ω)

TOP

MARK

PACKAGE CODE

MAX5477ETE*

-40°C to +85°C

16 Thin QFN

10

ABO

T1633F-3

MAX5477EUD*

-40°C to +85°C

14 TSSOP

10

—

—

MAX5478ETE*

-40°C to +85°C

16 Thin QFN

50

ABP

T1633F-3

MAX5478EUD

-40°C to +85°C

14 TSSOP

50

—

—

MAX5479ETE*

-40°C to +85°C

16 Thin QFN

100

ABQ

T1633F-3

MAX5479EUD

-40°C to +85°C

14 TSSOP

100

—

—

*Future product—contact factory for availability.