MAX7219/MAX7221
Serially Interfaced, 8-Digit LED Display Drivers
General Description
The MAX7219/MAX7221 are compact, serial input/output common-cathode display drivers that interface
microprocessors (µPs) to 7-segment numeric LED displays of up to 8 digits, bar-graph displays, or 64 individual 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 segment current for all LEDs. The MAX7221 is compatible
with SPI™, QSPI™, and MICROWIRE™, and has slewrate-limited segment drivers to reduce EMI.
A convenient 4-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 codeB decoding or no-decode for each digit.
The devices include a 150µA low-power shutdown
mode, analog and digital brightness control, a scanlimit register that allows the user to display from 1 to 8
digits, and a test mode that forces all LEDs on.
For applications requiring 3V operation or segment
blinking, refer to the MAX6951 data sheet.
Applications
Bar-Graph Displays
Industrial Controllers
Panel Meters
LED Matrix Displays
Features
♦ 10MHz Serial Interface
♦ Individual LED Segment Control
♦ Decode/No-Decode Digit Selection
♦ 150µA Low-Power Shutdown (Data Retained)
♦ Digital and Analog Brightness Control
♦ Display Blanked on Power-Up
♦ Drive Common-Cathode LED Display
♦ Slew-Rate Limited Segment Drivers
for Lower EMI (MAX7221)
♦ SPI, QSPI, MICROWIRE Serial Interface (MAX7221)
♦ 24-Pin DIP and SO Packages
Ordering Information
PART
TEMP RANGE
MAX7219CNG
0°C to +70°C
24 Narrow Plastic DIP
PIN-PACKAGE
MAX7219CWG
MAX7219C/D
MAX7219ENG
0°C to +70°C
0°C to +70°C
-40°C to +85°C
24 Wide SO
Dice*
24 Narrow Plastic DIP
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 TA = +25°C.
Typical Application Circuit
Pin Configuration
Functional Diagrams
TOP VIEW
DIN 1
24 DOUT
DIG 0 2
23 SEG D
DIG 4 3
22 SEG DP
DIG 6 5
+5V
21 SEG E
GND 4
MAX7219
MAX7221
19
9.53kΩ
20 SEG C
DIG 2 6
18 ISET
DIG 7 8
17 SEG G
GND 9
16 SEG B
18
19 V+
DIG 3 7
V+
DIG 5 10
15 SEG F
DIG 1 11
14 SEG A
LOAD (CS) 12
13 CLK
DIG 0–DIG 7
ISET
8 DIGITS
MOSI
μP
I/O
SCK
1
12
13
9
MAX7219
DIN
MAX7221
LOAD (CS)
SEG A–G,
SEG DP
CLK
GND
8 SEGMENTS
GND
4
Pin Configurations appear at end of data sheet.
( ) MAX7221 ONLY
DIP/SO
( ) MAX7221 ONLY
8-DIGIT μP DISPLAY
Functional Diagrams continued at end of data sheet.
UCSP is a trademark of Maxim Integrated Products, Inc.
SPI and QSPI are trademarks of Motorola Inc. MICROWIRE is a trademark of National Semiconductor Corp.
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-4452; Rev 4; 7/03
