General Description

The MAX6958/MAX6959 compact multiplexed com-

mon-cathode display drivers interface microprocessors

to seven-segment numeric LED digits, or discrete LEDs

interface. The 2-wire serial interface uses fixed

0.8V/2.1V logic thresholds for compatibility with 2.5V

and 3.3V systems when the display driver is powered

from a 5V supply.

The MAX6958/MAX6959 drive up to four 7-segment

digits, with decimal points, plus four discrete LEDs, or

four 7-segment digits and eight discrete LEDs if the

digits’ decimal points are not used, or up to 36 discrete

LEDs. The MAX6959 also includes two input ports, one

or both of which may be configured as a key-switch

reader, which automatically scans and debounces a

matrix of up to eight switches. Key-switch status is

obtained by polling internal status registers or by con-

figuring the MAX6959 interrupt output.

Other on-chip features include a hexadecimal font for

seven-segment displays, multiplex scan circuitry,

anode and cathode drivers, and static RAM that stores

each digit. The peak segment current for the display

digits is set internally to 23mA. Display intensity is

adjusted using a 64-step internal digital brightness con-

trol. The MAX6958/MAX6959 include a low-power shut-

down mode, a scan-limit register that allows the user to

display from one to four digits, and a test mode, which

forces all LEDs on. The LED drivers are slew-rate-limit-

ed to reduce EMI.

The MAX6958/MAX6959 are available in 16-pin PDIP

and QSOP packages and are fully specified over the

-40°C to +125°C automotive temperature range.

Applications

Features

o 400kbps 2-Wire Serial Interface

o 3V to 5.5V Operation

o Drive 4 Digits plus 4 or 8 Discrete LEDs

o Drive Common-Cathode LED Digits

o 23mA Constant-Current LED Segment Drive

o Hexadecimal Decode/No-Decode Digit Selection

o 64-Step Digital Brightness Control

o Slew-Rate-Limited Segment Drivers Reduced EMI

o Debounces Up to Eight Switches with n-Key

Rollover (MAX6959 Only)

o IRQ Output When a Key Input Is Debounced

(MAX6959 Only)

o 20µA Low-Power Shutdown (Data Retained)

o Automotive Temperature Range (-40°C to +125°C)

o Compact 16-Pin PDIP and QSOP Packages

2-Wire Interfaced, 3V to 5.5V, 4-Digit,

9-Segment LED Display Drivers with Keyscan

________________________________________________________________ Maxim Integrated Products

1

Ordering Information

19-2634; Rev 0; 10/02

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.

Ordering Information continued at end of data sheet.

*EP = Exposed pad.

PART

TEMP

RANGE

SLAVE

ADDRESS

PIN-

PACKAGE

MAX6958AAEE

-40

°C to +125°C

0111000

16 QSOP-EP*

MAX6958AAPE

-40

°C to +125°C

0111000

16 DIP

V+

DIG0–DIG3

SEG0–SEG8

SDA

SCL

IRQ/SEG9

INPUT1

µC

SDA

SCL

IRQ

8

INPUT2

GND

8

8

8

8

5V

DIG0/SEG0

DIG1/SEG1

DIG2/SEG2

DIG3/SEG3

DIG4/SEG4

DIG5/SEG5

DIG6/SEG6

DIG7/SEG7

MAX6959

Typical Operating Circuit

SMBus is a trademark of Intel Corp.

Set-Top Boxes

Panel Meters

White Goods

Audio/Video Equipment

Vending Machines

Industrial Controls

Pin Configuration, Functional Diagram, and Typical

Application Circuit appear at end of data sheet.