19-4452; Rev 3; 7/97
Serially Interfaced, 8-Digit LED Display Drivers
_______________General Description
The MAX7219/MAX7221 are compact, serial input/out-
put common-cathode display drivers that interface
microprocessors (µPs) to 7-segment numeric LED dis-
plays of up to 8 digits, bar-graph displays, or 64 indi-
vidual LEDs. Included on-chip are a BCD code-B
decoder, multiplex scan circuitry, segment and digit
drivers, and an 8x8 static RAM that stores each digit.
Only one external resistor is required to set the seg-
ment current for all LEDs. The MAX7221 is compatible
with SPI™, QSPI™, and Microwire™, and has slew-rate-
limited segment drivers to reduce EMI.
A convenient 3-wire serial interface connects to all
common µPs. Individual digits may be addressed and
updated without rewriting the entire display. The
MAX7219/MAX7221 also allow the user to select code-
B decoding or no-decode for each digit.
The devices include a 150µA low-power shutdown
mode, analog and digital brightness control, a scan-
limit register that allows the user to display from 1 to 8
digits, and a test mode that forces all LEDs on.
____________________________Features
o
10MHz Serial Interface
o
Individual LED Segment Control
o
Decode/No-Decode Digit Selection
o
150µA Low-Power Shutdown (Data Retained)
o
Digital and Analog Brightness Control
o
Display Blanked on Power-Up
o
Drive Common-Cathode LED Display
o
Slew-Rate Limited Segment Drivers
for Lower EMI (MAX7221)
o
SPI, QSPI, Microwire Serial Interface (MAX7221)
o
24-Pin DIP and SO Packages
MAX7219/MAX7221
______________Ordering Information
PART
MAX7219CNG
MAX7219CWG
MAX7219C/D
MAX7219ENG
TEMP. RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
-40°C to +85°C
PIN-PACKAGE
24 Narrow Plastic DIP
24 Wide SO
Dice*
24 Narrow Plastic DIP
________________________Applications
Bar-Graph Displays
7-Segment Displays
Industrial Controllers
Panel Meters
LED Matrix Displays
MAX7219EWG
-40°C to +85°C
24 Wide SO
MAX7219ERG
-40°C to +85°C
24 Narrow CERDIP
Ordering Information continued at end of data sheet.
*Dice are specified at T
A
= +25°C.
__________________Pin Configuration
TOP VIEW
DIN 1
DIG 0 2
DIG 4 3
GND 4
DIG 6 5
DIG 2 6
DIG 3 7
DIG 7 8
GND 9
DIG 5 10
DIG 1 11
LOAD (CS) 12
( ) MAX7221 ONLY
24 DOUT
23 SEG D
22 SEG DP
21 SEG E
________Typical Application Circuit
+5V
19
9.53k
18
I
SET
V+
DIG 0–DIG 7
8 DIGITS
MOSI
µP
I/O
SCK
1
12
13
9
MAX7219
MAX7221
20 SEG C
19 V+
18 ISET
17 SEG G
16 SEG B
15 SEG F
14 SEG A
13 CLK
MAX7219
DIN
MAX7221
LOAD (CS)
CLK
GND
GND
4
SEG A–G,
SEG DP
8 SEGMENTS
DIP/SO
( ) MAX7221 ONLY
8-DIGIT
µP
DISPLAY
SPI and QSPI are trademarks of Motorola Inc. Microwire is a trademark of National Semiconductor Corp.
________________________________________________________________
Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 408-737-7600 ext. 3468.
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
