ICM7218 Datasheet, PDF (1/11 Pages) Maxim Integrated Products – 8 Digit LED Display Driver

®
Data Sheet
February 15, 2007
ICM7218
FN3159.2
8-Digit LED Microprocessor-Compatible
Multiplexed Display Decoder Driver
The ICM7218 series of universal LED driver systems
provide, in a single package, all the circuitry necessary to
interface most common microprocessors or digital systems
to an LED display. Included on chip are an 8-byte static
display memory, two types of 7-segment decoders, multiplex
scan circuitry, and high current digit and segment drivers for
either common-cathode or common-anode displays.
The lCM7218A and 1CM7218B feature two control lines
(WRITE and MODE) which write either 4 bits of control
information (DATA COMING, SHUTDOWN, DECODE, and
HEXA/CODE B) or 8 bits of display input data. Display data
is automatically sequenced into the 8-byte internal memory
on successive positive going WRITE pulses. Data may be
displayed either directly or decoded in Hexadecimal or Code
B formats.
The ICM7218C and lCM7218D feature two control lines
(WRITE and HEXA/CODE B/SHUTDOWN), 4 separate
display data input lines, and 3 digit address lines. Display
data is written into the internal memory by setting up a digit
address and strobing the WRITE line low. Only Hexadecimal
and Code B formats are available for display outputs.
Features
• Microprocessor Compatible
• Total Circuit Integration On Chip Includes:
- Digit and Segment Drivers
- All Multiplex Scan Circuitry
- 8-Byte Static Display Memory
- 7-Segment Hexadecimal and Code B Decoders
• Output Drive Suitable for LED Displays Directly
• Common Anode and Common Cathode Versions
• Single 5V Supply Required
• Data Retention to 2V Supply
• Shutdown Feature - Turns Off Display and Puts Chip Into
Low Power Dissipation Mode
• Sequential and Random Access Versions
• Decimal Point Drive On Each Digit
Related Literature
• Technical Brief TB363 “Guidelines for Handling and
Processing Moisture Sensitive Surface Mount Devices
(SMDs)”
ID0-ID7
INPUT
DATA
8
ICM7218A COMMON ANODE
ICM7218B COMMON CATHODE
ID4-ID7 MODE WRITE
8 CONTROL
INPUTS
4
1
1
1
1
7
4
DECODE
HEXA/CODE B
8-BYTE
STATIC
RAM
CONTROL
SHUTDOWN
LOGIC
1
1
8
WRITE ADDRESS
8
COUNTER
1
8
READ
ADRESS, DIGIT
MULTIPLEXER
HEXADECIMAL/
CODE B
7
DECODER
7
3
MULTIPLEX
OSCILLATOR
DECODE/
1
NO-DECODE
7
DECIMAL
POINT
8-SEGMENT
DRIVERS
1
8
8-DIGIT
DRIVERS
INTERDIGIT
BLANKING
ICM7218C COMMON ANODE
ICM7218D COMMON CATHODE
HEXADECIMAL/
CODE B/
SHUTDOWN
1
ID0-ID3
ID7
DATA
INPUT
5
WRITE
1
DA0-DA2
DIGIT
ADDRESS
3
THREE LEVEL ¹
INPUT LOGIC
1
8
8-BYTE
STATIC
RAM
8
4
SHUTDOWN
WRITE
ADDRESS
DECODER
8
READ
ADRESS
MULTIPLEXER
HEXADECIMAL/
CODE B
DECODER
1
8
7
DECIMAL
POINT
5
MULTIPLEX
OSCILLATOR
1 _INTERDIGIT
BLANKING
8-SEGMENT
DRIVERS
8-DIGIT
DRIVERS
FIGURE 1. FUNCTIONAL DIAGRAMS
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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