Product Summary

The lm3909n is a monolithic oscillator specifically designed to flash Light Emitting Diodes. By using the timing capacitor for voltage boost, it delivers pulses of 2 or more volts to the LED while operating on a supply of 1.5V or less. The lm3909n is inherently self-starting, and requires addition of only a battery and capacitor to function as an LED flasher. The applications of the lm3909n include Finding flashlights in the dark, or locating boat mooring floats, Sales and advertising gimmicks, Emergency locators, for instance on fire extinguishers, Toys and novelties, Electronic applications such as trigger and sawtooth generators, Siren for toy fire engine, (combined oscillator, speaker driver), Warning indicators powered by 1.4V to 200V.

Parametrics

lm3909n absolute maximum ratings: (1)Power Dissipation: 500 mW; (2)Va Voltage: 6.4V; (3)Operating Temperature Range: -25℃ to +70℃; (4)Lead Temperature (Soldering, 10 sec.): 260℃.

Features

lm3909n features: (1)Operation over one year from one C size flashlight cell; (2)Bright, high current LED pulse; (3)Minimum external parts; (4)Low cost; (5)Low voltage operation, from just over 1V to 5V; (6)Low current drain, averages under 0.5 mA during battery life; (7)Powerful; as an oscillator directly drives an 8X speaker; (8)Wide temperature range.

Diagrams

lm3909n block diagram