MAX6958 Datasheet, PDF (1/19 Pages) Maxim Integrated Products – 2-Wire Interfaced, 3V to 5.5V, 4-Digit, 9-Segment LED Display Drivers with Keyscan

19-2634; Rev 0; 10/02
2-Wire Interfaced, 3V to 5.5V, 4-Digit,
9-Segment LED Display Drivers with Keyscan
General Description
The MAX6958/MAX6959 compact multiplexed com-
mon-cathode display drivers interface microprocessors
to seven-segment numeric LED digits, or discrete LEDs
through an SMBus™- and I²C-compatible 2-wire serial
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.
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
Ordering Information
PART
TEMP
RANGE
SLAVE PIN-
ADDRESS PACKAGE
MAX6958AAEE -40°C to +125°C 0111000 16 QSOP-EP*
MAX6958AAPE -40°C to +125°C 0111000 16 DIP
Ordering Information continued at end of data sheet.
*EP = Exposed pad.
Typical Operating Circuit
8
8
8
8
Set-Top Boxes
Panel Meters
White Goods
Applications
Audio/Video Equipment
Vending Machines
Industrial Controls
Pin Configuration, Functional Diagram, and Typical
Application Circuit appear at end of data sheet.
SMBus is a trademark of Intel Corp.
µC
SDA
SCL
IRQ
SDA
SCL
IRQ/SEG9
DIG0–DIG3 8
SEG0–SEG8
5V
V+
MAX6959
INPUT1
INPUT2
GND
Key0
DIG0/SEG0
Key1
DIG1/SEG1
Key2
DIG2/SEG2
Key3
DIG3/SEG3
Key4
DIG4/SEG4
Key5
DIG5/SEG5
Key6
DIG6/SEG6
Key7
DIG7/SEG7
________________________________________________________________ Maxim Integrated Products 1
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.