Rainbow Electronics MAX6959 - Manual

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 I
2 C-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.
Applications
Features
♦ 400kbps 2-Wire Serial Interface
♦ 3V to 5.5V Operation
♦ Drive 4 Digits plus 4 or 8 Discrete LEDs
♦ Drive Common-Cathode LED Digits
♦ 23mA Constant-Current LED Segment Drive
♦ Hexadecimal Decode/No-Decode Digit Selection
♦ 64-Step Digital Brightness Control
♦ Slew-Rate-Limited Segment Drivers Reduced EMI
♦ Debounces Up to Eight Switches with n-Key
Rollover (MAX6959 Only)
♦ IRQ Output When a Key Input Is Debounced
(MAX6959 Only)
♦ 20µA Low-Power Shutdown (Data Retained)
♦ Automotive Temperature Range (-40°C to +125°C)
♦ Compact 16-Pin PDIP and QSOP Packages
MAX6958/MAX6959
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 QS O P - E P *
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
Key 0
DIG0/SEG0
Key 1
DIG1/SEG1
Key 2
DIG2/SEG2
Key 3
DIG3/SEG3
Key 4
DIG4/SEG4
Key 5
DIG5/SEG5
Key 6
DIG6/SEG6
Key 7
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.