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
• 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
• Industrial control indicator
• Relay driver
• Digital clock, thermometer, counter, voltmeter
• Instrumentation readouts
Ordering Information
Part Number
Standard Pb-Free
MM5450BN MM5450YN
MM5451BN MM5451YN
MM5450BV MM5450YV
MM5451BV MM5451YV
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 PDIP
40-pin PDIP
44-pin PLCC
44-pin PLCC
____________________________________________________________________________________________________________
Block Diagram
BRIGHTNESS
CONTROL
OUT 34
VDD
20 24
OUT 1
18
19
35 OUTPUT BUFFERS
DATA ENABLE/OUT 35 23
(See Note 1)
22
SERIAL DATA
21
CLOCK
35 LATCHES
LOAD
35-BIT SHIFT
REGISTER
RESET
Note 1: Pin 23 is Data Enable in MM5450
Pin 23 is Output 35 in MM5451
Figure 1.
RESET
(only available
1
in die form)
SuperSwitcher and Super ßeta PNP are trademarks of Micrel, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
February 2006
M9999-021606
(408) 955-1690