LM3909 replaced???

[mindctrl]

Hi everybody,

OK - what's up with this? I got an LM3909 at Radio Shack. It was the last one on the shelf, part # 276-1705. When I told my friend I found one, his eyes lit up and said "You found one?! Nobody carries those anymore! Where did you get it?!" I told him Radio Shack, he said it was a lucky find. I gave it to him, and now I wanted to use it in a project. I looked on Digi-Key and Mouser, but they didn't carry them anymore. My guess is that the LM3909 isn't manufactured anymore and has been replaced by something.

What was it replaced by? Is there a better chip to use to drive LEDs (other then the 555)? I'm just wondering. Thanks for the replies!

--mindctrl

 

[k7elp60]

Well the biggest advantage of the LM3909 is the fact that it would flash LED's from a 1.5 volt battery. Unfortunately the 555 isn't specified to work on that low of voltage.

The closest thing are the flashing LED's, but they won't work on 1.5 volts either.

If you look at the internal schematic of the LM3909 is has about 4 transistors plus a diode in the package.
I developed a flasher that works on 1.5 V that uses 4 transistors.
The schematic is attached.

I occasionally see LM3909's on EBAY, but the price is generally pretty
high.

 

[Phasor]

Yes, the LM3909 was discontinued quite some time ago. It might interest you to have a look at these pages:

**broken link removed** - LM3909 implemented with discrete components

https://www.electro-tech-online.com/custompdfs/2005/01/nte876.pdf - A different LED flasher IC

 

[THESTOCKSGUY]

LM3909 relief

Your resolution is 555 SMT's @ 20 cents each with a schematic.
thestocksguy@hotmail.com

Hi everybody,

OK - what's up with this? I got an LM3909 at Radio Shack. It was the last one on the shelf, part # 276-1705. When I told my friend I found one, his eyes lit up and said "You found one?! Nobody carries those anymore! Where did you get it?!" I told him Radio Shack, he said it was a lucky find. I gave it to him, and now I wanted to use it in a project. I looked on Digi-Key and Mouser, but they didn't carry them anymore. My guess is that the LM3909 isn't manufactured anymore and has been replaced by something.

What was it replaced by? Is there a better chip to use to drive LEDs (other then the 555)? I'm just wondering. Thanks for the replies!

--mindctrl[/QUOTE]

 

[Nigel Goodwin]

It wasn't replaced by anything, it was discontinued - end of story.

 

[audioguru]

National Semi hoped that every flashlight would have an LM3909 in it so it could be seen in the dark but I don't think any flashlights were made with it.
So when every hobbiest bought an IC (including me) then nobody bought them anymore and they stopped making them.

 

[fernando_g]

The LM3909...does bring back some fond memories.

Unfortunately, as audio guru mentioned, this was a device which mostly caught with the hobbysts...not a way to make money for a large corporation. So it was discontinued.

 

[woodyboy189]

7000 + LM3909's in stock

$5.99 each...no minimum purchase through April...stock up

American Microsemiconductor manufacturers of Diodes, Transistors, Thyristors, Triacs, Diode Array, Integrated Circuits and Semiconductors -- Online Store

 

[Sceadwian]

The last AVR (read micro controller) I bought from Digikey was 50 cents per piece I bought a half dozen of them. They were discontinued though, the next model up is a dollar. 8 pin DIP could flash 4 LED's at almost any rate you can think of, that gives you 4 dollars to spend on a 5V boost regulators =)

 

[asebe]

I believe NTE876 work the same as LM3909.

 

[cachehiker]

I occasionally see LM3909's on EBAY, but the price is generally pretty high.

You went and got me all excited. I'm fairly certain I have a whole tube of them.

A few bucks each was a bit of a let down. I suppose I could net $20 and a dozen feedback points though.

Once upon a time, I made $10 apiece for a half dozen fake car alarms built with them.

 

[colin55]

LM3909 is $2.00 on eBay and $1.50 postage
**broken link removed**