|
|
PDF MAX7221 Data sheet ( Hoja de datos )
| Número de pieza | MAX7221 | |
| Descripción | Serially Interfaced / 8-Digit LED Display Drivers | |
| Fabricantes | Maxim Integrated | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de MAX7221 (archivo pdf) en la parte inferior de esta página. Total 17 Páginas | ||
|
No Preview Available !
AVAILABLE
MAX7219/MAX7221
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.
Applications
Bar-Graph Displays
Panel Meters
Industrial Controllers
LED Matrix Displays
FuncPtiinonCaolnDfiigaugrraatmiosn
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 PIN-PACKAGE
MAX7219CNG 0°C to +70°C 24 Narrow Plastic DIP
MAX7219CWG 0°C to +70°C 24 Wide SO
MAX7219C/D
0°C to +70°C Dice*
MAX7219ENG -40°C to +85°C 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
TOP VIEW
DIN 1
24 DOUT
DIG 0 2
23 SEG D
DIG 4 3
22 SEG DP
+5V
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
MAX7219
MAX7221
21 SEG E
20 SEG C
19 V+
18 ISET
17 SEG G
16 SEG B
15 SEG F
14 SEG A
13 CLK
9.53kΩ
MOSI
μP I/O
SCK
19
V+
18
ISET
DIG 0–DIG 7
8 DIGITS
1
DIN
MAX7219
MAX7221
12 LOAD (CS)
13 CLK
9 GND
SEG A–G,
SEG DP 8 SEGMENTS
GND
4
Pin Configurations appear at end of data sheet.
Functi(o) nMaAXl 7D22ia1 gONraLYms continueDdIPa/tSeOnd of data sheet.
( ) MAX7221 ONLY
8-DIGIT μP DISPLAY
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
1 page  
MAX7219/MAX7221
Serially Interfaced, 8-Digit LED Display Drivers
Pin Description
PIN
1
2, 3, 5–8,
10, 11
4, 9
12
13
14–17,
20–23
18
19
24
NAME
DIN
DIG 0–DIG 7
GND
LOAD
(MAX7219)
CS
(MAX7221)
CLK
SEG A–SEG G,
DP
ISET
V+
DOUT
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 VDD through a resistor (RSET) to set the peak segment current (Refer to Selecting
RSET 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.
Functional Diagram
SEG A–SEG G, DP
SEGMENT DRIVERS
DIG 0–DIG 7
DIGIT DRIVERS
8
SEGMENT
CURRENT
REFERENCE
V+
RSET
8
CODE B
ROM WITH
BYPASS
8
8x8
DUAL-PORT
SRAM
LOAD (CS)
8
SHUTDOWN REGISTER
MODE REGISTER
INTENSITY REGISTER
SCAN-LIMIT REGISTER
DISPLAY-TEST REGISTER
ADDRESS
8 REGISTER
DECODER
4
DIN D0 D1 D2 D3 D4 D5 D6 D7 D8 D9 D10 D11 D12 D13 D14 D15
CLK
( ) MAX7221 ONLY
(LSB)
(MSB)
INTENSITY
PULSE-
WIDTH
MODULATOR
MULTIPLEX
SCAN
CIRCUITRY
DOUT
Maxim Integrated
5
5 Page 
MAX7219/MAX7221
Serially Interfaced, 8-Digit LED Display Drivers
Table 11. RSET vs. Segment Current and
LED Forward Voltage
ISEG (mA)
40
30
20
10
1.5
12.2
17.8
29.8
66.7
VLED (V)
2.0 2.5 3.0
11.8 11.0 10.6
17.1 15.8 15.0
28.0 25.9 24.5
63.7 59.3 55.4
3.5
9.69
14.0
22.6
51.2
Table 12. Package Thermal Resistance
Data
PACKAGE
THERMAL RESISTANCE
(θJA)
24 Narrow DIP
+75°C/W
24 Wide SO
+85°C/W
24 CERDIP
+80°C/W
Maximum Junction Temperature (TJ) = +150°C
Maximum Ambient Temperature (TA) = +85°C
Computing Power Dissipation
The upper limit for power dissipation (PD) for the
MAX7219/MAX7221 is determined from the following
equation:
PD = (V+ x 8mA) + (V+ - VLED)(DUTY x ISEG x N)
where:
V+ = supply voltage
DUTY = duty cycle set by intensity register
N = number of segments driven (worst case is 8)
VLED = LED forward voltage
ISEG = segment current set by RSET
Dissipation example:
ISEG = 40mA, N = 8, DUTY = 31/32, VLED = 1.8V at
40mA, V+ = 5.25V
PD = (5.25V x 8mA) + (5.25V - 1.8V)(31/32 x
40mA x 8) = 1.11W
Thus, for a CERDIP package (θJA = +80°C/W from
Table 12), the maximum allowed ambient temperature
TA is given by:
TJ(MAX) = TA + PD x θJA
150°C = TA +1.11W x 80°C/W
where TA = +61.2°C.
The TA limits for PDIP and SO packages in the dissipation
example above are +66.7°C and +55.6°C, respectively.
Cascading Drivers
The example in Figure 3 drives 16 digits using a 3-wire
µP interface. If the number of digits is not a multiple of
8, set both drivers’ scan limits registers to the same
number so one display will not appear brighter than the
other. For example, if 12 digits are need, use 6 digits
per display with both scan-limit registers set for 6 digits
so that both displays have a 1/6 duty cycle per digit. If
11 digits are needed, set both scan-limit registers for 6
digits and leave one digit driver unconnected. If one
display for 6 digits and the other for 5 digits, the sec-
ond display will appear brighter because its duty cycle
per digit will be 1/5 while the first display’s will be 1/6.
Refer to the No-Op Register section for additional infor-
mation.
Maxim Integrated
11
11 Page | ||
| Páginas | Total 17 Páginas | |
| PDF Descargar | [ Datasheet MAX7221.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| MAX722 | PALMTOP COMPUTER AND LCD POWER SUPPLY REGULATORS | Maxim Integrated |
| MAX7221 | Serially Interfaced / 8-Digit LED Display Drivers | Maxim Integrated |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |