ELM711
Christmas LEDs Driver
Description
The ELM711 is a sequencing circuit that is
typically used to control strings of LEDs on
Christmas trees. No external components are
needed for its operation, as all timing and logic
functions are performed internally.
Each high current output is capable of directly
driving an LED, but in order to drive a string of LEDs,
a higher voltage supply and an interface circuit
(typically a transistor and two resistors) are required.
See the Example Applications section for a short
discussion on how you might typically build such a
circuit.
Note that this integrated circuit uses rapid PWM
switching techniques to perform the LED dimming,
so this device is not suitable for use with slow
interface devices such as electro-mechanical relays.
Features
• One button controls power and patterns
• Needs no external timing components
• Eight different patterns
• Debounced control switch input
• Wide supply range – 3.0 to 5.5 volts
• High current drive outputs
• Low power CMOS design
Connection Diagram
PDIP and SOIC
(top view)
Applications
• Christmas LED lighting control
• Marquee lighting
• Display attention grabbers
V
DD
Blue
White
PB
1
2
3
4
8
7
6
5
V
SS
Green
Yellow
Red
Block Diagram
White
Blue
Green
Yellow
Red
3
power
control
V
DD
PB
4
2
pattern
generator
switch
debounce
7
6
5
ELM711DSA
Elm Electronics – Circuits for the Hobbyist
< http://www.elmelectronics.com/ >
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