MM5450/5451
Micrel
MM5450/5451
LED Display Driver
General Description
The MM5450 and MM5451 LED display drivers are monolithic
MOS IC’s fabricated in an N-Channel, metal-gate process.
The technology produces low-threshold, enhancement-mode,
and ion-implanted depletion-mode devices.
A single pin controls the LED display brightness by setting a
reference current through a variable resistor connected to
the supply.
Features
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Continuous brightness control
Serial data input
No load signal requirement
Enable (on MM5450)
Wide power supply operation
TTL compatibility
34 or 35 outputs, 15mA capability
Alphanumeric capability
Applications
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Industrial control indicator
Relay driver
Digital clock, thermometer, counter, voltmeter
Instrumentation readouts
Ordering Information
Part Number
MM5450BN
MM5451BN
MM5450BV
MM5451BV
Junction Temp. Range
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
Package
40-pin Plastic DIP
40-pin Plastic DIP
44-pin PLCC
44-pin PLCC
Block Diagram
VDD
BRIGHTNESS
CONTROL
19
20
OUT 34
24
OUT 1
18
35 OUTPUT BUFFERS
35 LATCHES
DATA ENABLE/OUT 35 23
(See Note 1)
SERIAL DATA
22
35-BIT SHIFT
REGISTERS
LOAD
RESET
CLOCK
21
1
Note 1: Pin 23 is Data Enable in MM5450
Pin 23 is Output 35 in MM5451
Figure 1.
RESET
(only available
in die form)
870 01
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
May 2000
1
MM5450/5451
MICREL [ MICREL SEMICONDUCTOR ]
