_______________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 SPITM, QSPITM, and MicrowireTM, 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.
________________________Applications
Bar-Graph Displays
7-Segment Displays
Industrial Controllers
Panel Meters
LED Matrix Displays
____________________________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
Serially Interfaced, 8-Digit LED Display Drivers
________________________________________________________________
Maxim Integrated Products
1
( ) MAX7221 ONLY
8-DIGIT
µ
P DISPLAY
DIG 0DIG 7
MOSI
I/O
SCK
18
1
12
13
9
4
DIN
µ
P
I
SET
9.53k
8 DIGITS
8 SEGMENTS
+5V
19
SEG AG,
SEG DP
CLK
LOAD (CS)
GND
V+
GND
MAX7219
MAX7221
________Typical Application Circuit
__________________Pin Configuration
24
23
22
21
20
19
18
17
1
2
3
4
5
6
7
8
DOUT
SEG D
SEG DP
SEG E
GND
DIG 4
DIG 0
DIN
TOP VIEW
SEG C
V+
ISET
SEG G
DIG 7
DIG 3
DIG 2
DIG 6
16
15
14
13
9
10
11
12
SEG B
SEG F
SEG A
CLK
( ) MAX7221 ONLY
LOAD (CS)
DIG 1
DIG 5
GND
DIP/SO
MAX7219
MAX7221
19-4452; Rev 3; 7/97
PART
MAX7219
CNG
MAX7219CWG
MAX7219C/D
0°C to +70°C
0°C to +70°C
0°C to +70°C
TEMP. RANGE
PIN-PACKAGE
24 Narrow Plastic DIP
24 Wide SO
Dice*
______________Ordering Information
Ordering Information continued at end of data sheet.
*Dice are specified at T
A
= +25°C.
MAX7219ENG
MAX7219EWG
MAX7219ERG
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
24 Narrow Plastic DIP
24 Wide SO
24 Narrow CERDIP
SPI and QSPI are trademarks of Motorola Inc. Microwire is a trademark of National Semiconductor Corp.
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.
MAX7219/MAX7221
Serially Interfaced, 8-Digit LED Display Drivers
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V+ = 5V ±10%, R
SET
= 9.53k
±1%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
Voltage (with respect to GND)
V+ ............................................................................-0.3V to 6V
DIN, CLK, LOAD, CS ...............................................-0.3V to 6V
All Other Pins.............................................-0.3V to (V+ + 0.3V)
Current
DIG0DIG7 Sink Current................................................500mA
SEGAG, DP Source Current.........................................100mA
Continuous Power Dissipation (T
A
= +85°C)
Narrow Plastic DIP ..........................................................0.87W
Wide SO ..........................................................................0.76W
Narrow CERDIP.................................................................1.1W
Operating Temperature Ranges
MAX7219C_G/MAX7221C_G ..............................0°C to +70°C
MAX7219E_G/MAX7221E_G ............................-40°C to +85°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10sec) .............................+300°C
R
SET
= open circuit
All digital inputs at V+ or GND, T
A
= +25°C
Digit off, V
DIGIT
= V+
T
A
= +25°C, V+ = 5V, V
OUT
= (V+ - 1V)
All segments and decimal point on,
I
SEG_
= -40mA
8 digits scanned
V+ = 5V, V
OUT
= 0.65V
T
A
= +25°C, V+ = 5V, V
OUT
= (V+ - 1V)
CONDITIONS
8
Operating Supply Current
µA
150
I+
V
4.0
5.5
V+
Operating Supply Voltage
Shutdown Supply Current
µA
-10
I
DIGIT
Digit Drive Leakage
(MAX7221 only)
%
3.0
I
SEG
Segment Drive Current Matching
mA/µs
10
20
50
I
SEG
/
t
Segment Current Slew Rate
(MAX7221 only)
mA
330
I+
Hz
500
800
1300
f
OSC
Display Scan Rate
mA
320
I
DIGIT
Digit Drive Sink Current
mA
-30
-40
-45
I
SEG
Segment Drive Source Current
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
Segment off, V
SEG
= 0V
µA
1
I
SEG
Segment Drive Leakage
(MAX7221 only)
Digit off, V
DIGIT
= (V+ - 0.3V)
mA
-2
I
DIGIT
Digit Drive Source Current
(MAX7219 only)
Segment off, V
SEG
= 0.3V
mA
5
I
SEG
Segment Drive Sink Current
(MAX7219 only)
MAX7219/MAX7221
Serially Interfaced, 8-Digit LED Display Drivers
_______________________________________________________________________________________
3
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 5V ±10%, R
SET
=9.53k
±1%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
V
IN
= 0V or V+
DOUT, I
SINK
= 1.6mA
DOUT, I
SOURCE
= -1mA
CONDITIONS
µA
-1
1
I
IH
, I
IL
Input Current DIN, CLK,
LOAD, CS
V
0.4
V
OL
Output Low Voltage
V
3.5
V
IH
Logic High Input Voltage
V
0.8
V
IL
Logic Low Input Voltage
V
V+ - 1
V
OH
Output High Voltage
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
DIN, CLK, LOAD, CS
V
1
V
I
Hysteresis Voltage
ns
25
t
CSS
CS Fall to SCLK Rise Setup Time
(MAX7221 only)
ns
100
t
CP
CLK Clock Period
ns
50
t
CH
CLK Pulse Width High
ns
50
t
CL
CLK Pulse Width Low
C
LOAD
= 50pF
ns
25
t
DS
DIN Setup Time
ns
50
t
CSW
Minimum CS or LOAD Pulse
High
ns
0
t
DH
DIN Hold Time
ns
25
t
DO
Output Data Propagation Delay
ns
50
t
LDCK
Load-Rising Edge to Next Clock
Rising Edge (MAX7219 only)
ns
0
t
CSH
CLK Rise to CS or LOAD Rise
Hold Time
ms
2.25
t
DSPD
Data-to-Segment Delay
LOGIC INPUTS
TIMING CHARACTERISTICS
MAX7219/MAX7221
Serially Interfaced, 8-Digit LED Display Drivers
4
_______________________________________________________________________________________
__________________________________________Typical Operating Characteristics
(V+ = +5V, T
A
= +25°C, unless otherwise noted.)
730
750
740
770
760
790
780
800
820
810
830
4.0
4.4
4.8
5.2
5.6
6.0
SCAN FREQUENCY vs.
POSITIVE SUPPLY VOLTAGE
MAX7219/21 01
POSITIVE SUPPLY VOLTAGE (V)
SCAN FREQUENCY (Hz)
0
20
10
40
30
60
50
70
0
1
2
3
4
5
SEGMENT DRIVER OUTPUT CURRENT
vs. OUTPUT VOLTAGE
MAX7219/21 02
OUTPUT VOLTAGE (V)
OUTPUT CURRENT (mA)
R
SET
= 10k
R
SET
= 20k
R
SET
= 40k
MAX7219
SEGMENT OUTPUT CURRENT
MAX7219/21 03
5
µ
s/div
10mA/div
0
MAXIMUM INTENSITY = 31/32
MAX7221
SEGMENT OUTPUT CURRENT
MAX7219/21 04
5
µ
s/div
10mA/div
0
MAXIMUM INTENSITY = 15/16
MAX7219/MAX7221
Serially Interfaced, 8-Digit LED Display Drivers
_______________________________________________________________________________________
5
______________________________________________________________Pin Description
_________________________________________________________Functional Diagram
NAME
FUNCTION
1
DIN
Serial-Data Input. Data is loaded into the internal 16-bit shift register on CLK's rising edge.
2, 3, 58,
10, 11
DIG 0DIG 7
Eight-Digit Drive Lines that sink current from the display common cathode. The MAX7219 pulls
the digit outputs to V+ when turned off. The MAX7221's digit drivers are high-impedance when
turned off.
PIN
4, 9
GND
Ground (both GND pins must be connected)
12
LOAD
(MAX7219)
18
ISET
Connect to V
DD
through a resistor (R
SET
) to set the peak segment current (Refer to
Selecting
R
SET
Resistor section).
1417,
2023
SEG ASEG G,
DP
13
CLK
CS
(MAX7221)
24
DOUT
Serial-Data Output. The data into DIN is valid at DOUT 16.5 clock cycles later. This pin is used
to daisy-chain several MAX7219/MAX7221's and is never high-impedance.
19
V+
Positive Supply Voltage. Connect to +5V.
( ) MAX7221 ONLY
V+
8
8
8
8
4
R
SET
LOAD (CS)
DIN
DOUT
CLK
(MSB)
(LSB)
D0
SEG ASEG G, DP
DIG 0DIG 7
SHUTDOWN REGISTER
MODE REGISTER
INTENSITY REGISTER
SCAN-LIMIT REGISTER
DISPLAY-TEST REGISTER
INTENSITY
PULSE-
WIDTH
MODULATOR
MULTIPLEX
SCAN
CIRCUITRY
ADDRESS
REGISTER
DECODER
8x8
DUAL-PORT
SRAM
8
D1 D2 D3 D4 D5 D6 D7 D8 D9 D10 D11 D12
DIGIT DRIVERS
D13 D14 D15
CODE B
ROM WITH
BYPASS
SEGMENT
CURRENT
REFERENCE
SEGMENT DRIVERS
Load-Data Input. The last 16 bits of serial data are latched on LOAD's rising edge.
Chip-Select Input. Serial data is loaded into the shift register while CS is low. The last 16 bits of
serial data are latched on CS's rising edge.
Serial-Clock Input. 10MHz maximum rate. On CLK's rising edge, data is shifted into the inter-
nal shift register. On CLK's falling edge, data is clocked out of DOUT. On the MAX7221, the
CLK input is active only while CS is low.
Seven Segment Drives and Decimal Point Drive that source current to the display. On the
MAX7219, when a segment driver is turned off it is pulled to GND. The MAX7221 segment dri-
vers are high-impedance when turned off.
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