19-4452; Rev 4; 7/03
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 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 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.
For applications requiring 3V operation or segment
blinking, refer to the MAX6951 data sheet.
♦
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
Features
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
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
9.53kΩ
18
ISET
19
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 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.
Serially Interfaced, 8-Digit LED Display Drivers
MAX7219/MAX7221
ABSOLUTE MAXIMUM RATINGS
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
DIG 0–DIG 7 Sink Current..............................................500mA
SEG A–G, DP Source Current........................................100mA
Continuous Power Dissipation (T
A
= +85°C)
Narrow Plastic DIP (derate 13.3mW/°C
above +70°C)..............................................................1066mW
Wide SO (derate 11.8mW/°C above +70°C).................941mW
Narrow CERDIP (derate 12.5mW/°C above +70°C) ...1000mW
Operating Temperature Ranges (T
MIN
to T
MAX
)
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, 10s) .................................+300°C
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.
ELECTRICAL CHARACTERISTICS
(V+ = 5V ±10%, R
SET
= 9.53kΩ ±1%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
PARAMETER
Operating Supply Voltage
Shutdown Supply Current
Operating Supply Current
Display Scan Rate
Digit Drive Sink Current
Segment Drive Source Current
Segment Current Slew Rate
(MAX7221 only)
Segment Drive Current Matching
Digit Drive Leakage
(MAX7221 only)
Segment Drive Leakage
(MAX7221 only)
Digit Drive Source Current
(MAX7219 only)
Segment Drive Sink Current
(MAX7219 only)
SYMBOL
V+
I+
I+
f
OSC
I
DIGIT
I
SEG
ΔI
SEG
/Δt
ΔI
SEG
I
DIGIT
I
SEG
I
DIGIT
I
SEG
Digit off, V
DIGIT
= V+
Segment off, V
SEG
= 0V
Digit off, V
DIGIT
= (V+ - 0.3V)
Segment off, V
SEG
= 0.3V
-2
5
All digital inputs at V+ or GND, T
A
= +25°C
R
SET
= open circuit
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)
T
A
= +25°C, V+ = 5V, V
OUT
= (V+ - 1V)
500
320
-30
10
-40
20
3.0
-10
1
-45
50
330
800
1300
CONDITIONS
MIN
4.0
TYP
MAX
5.5
150
8
mA
Hz
mA
mA
mA/µs
%
µA
µA
mA
mA
UNITS
V
µA
2
_______________________________________________________________________________________
Serially Interfaced, 8-Digit LED Display Drivers
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 5V ±10%, R
SET
= 9.53kΩ ±1%, T
A
= T
MIN
to T
MAX
, unless otherwise noted.)
PARAMETER
LOGIC INPUTS
Input Current DIN, CLK,
LOAD,
CS
Logic High Input Voltage
Logic Low Input Voltage
Output High Voltage
Output Low Voltage
Hysteresis Voltage
TIMING CHARACTERISTICS
CLK Clock Period
CLK Pulse Width High
CLK Pulse Width Low
CS
Fall to SCLK Rise Setup Time
(MAX7221 only)
CLK Rise to
CS
or LOAD Rise
Hold Time
DIN Setup Time
DIN Hold Time
Output Data Propagation Delay
Load-Rising Edge to Next Clock
Rising Edge (MAX7219 only)
Minimum
CS
or LOAD Pulse
High
Data-to-Segment Delay
t
CP
t
CH
t
CL
t
CSS
t
CSH
t
DS
t
DH
t
DO
t
LDCK
t
CSW
t
DSPD
C
LOAD
= 50pF
50
50
2.25
100
50
50
25
0
25
0
25
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ms
I
IH
, I
IL
V
IH
V
IL
V
OH
V
OL
ΔV
I
DOUT, I
SOURCE
= -1mA
DOUT, I
SINK
= 1.6mA
DIN, CLK, LOAD,
CS
1
V+ - 1
0.4
V
IN
= 0V or V+
-1
3.5
0.8
1
µA
V
V
V
V
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX7219/MAX7221
_______________________________________________________________________________________
3
Serially Interfaced, 8-Digit LED Display Drivers
MAX7219/MAX7221
__________________________________________Typical Operating Characteristics
(V+ = +5V, T
A
= +25°C, unless otherwise noted.)
SCAN FREQUENCY vs.
POSITIVE SUPPLY VOLTAGE
MAX7219/21 01
SEGMENT DRIVER OUTPUT CURRENT
vs. OUTPUT VOLTAGE
MAX7219/21 02
830
820
810
SCAN FREQUENCY (Hz)
800
790
780
770
760
750
740
730
4.0
4.4
4.8
5.2
5.6
70
60
OUTPUT CURRENT (mA)
R
SET
= 10kΩ
50
40
30
20
10
0
R
SET
= 20kΩ
R
SET
= 40kΩ
6.0
0
1
2
3
4
5
POSITIVE SUPPLY VOLTAGE (V)
OUTPUT VOLTAGE (V)
MAX7219
SEGMENT OUTPUT CURRENT
MAX7219/21 03
MAX7221
SEGMENT OUTPUT CURRENT
MAXIMUM INTENSITY = 15/16
MAX7219/21 04
MAXIMUM INTENSITY = 31/32
10mA/div
10mA/div
0
0
5μs/div
5μs/div
4
_______________________________________________________________________________________
Serially Interfaced, 8-Digit LED Display Drivers
Pin Description
PIN
1
2, 3, 5–8,
10, 11
4, 9
NAME
DIN
DIG 0–DIG 7
GND
LOAD
(MAX7219)
CS
(MAX7221)
CLK
FUNCTION
Serial-Data Input. Data is loaded into the internal 16-bit shift register on CLK’s rising edge.
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.
Ground (both GND pins must be connected)
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.
Connect to V
DD
through a resistor (R
SET
) to set the peak segment current (Refer to
Selecting
R
SET
Resistor and Using External Drivers
section).
Positive Supply Voltage. Connect to +5V.
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.
MAX7219/MAX7221
12
13
14–17,
20–23
18
19
24
SEG A–SEG G,
DP
ISET
V+
DOUT
Functional Diagram
SEG A–SEG G, DP
SEGMENT DRIVERS
DIG 0–DIG 7
DIGIT DRIVERS
8
8
V+
CODE B
ROM WITH
BYPASS
R
SET
SEGMENT
CURRENT
REFERENCE
8
8x8
DUAL-PORT
SRAM
8
8
ADDRESS
REGISTER
DECODER
4
DIN
CLK
( ) MAX7221 ONLY
D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 D10 D11 D12 D13 D14 D15
DOUT
SHUTDOWN REGISTER
MODE REGISTER
INTENSITY REGISTER
SCAN-LIMIT REGISTER
DISPLAY-TEST REGISTER
MULTIPLEX
SCAN
CIRCUITRY
INTENSITY
PULSE-
WIDTH
MODULATOR
LOAD (CS)
(LSB)
(MSB)
_______________________________________________________________________________________
5
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