LED Serial Driver IC

[Cynar]

I'm trying to find a viable IC for a project, but all my searches are being bogged down in clutter.

I want to drive a couple of RGB LEDs via a serial type link. The annoyance is I need PWM on them and quite a few.

Effectively I need a shift register type IC with about 6 outputs with PWM. I'm not worried current wise, since I am driving it through a darlington array IC.

The best I have found so far is the TLC5940 (http://www.mouser.com/ds/2/405/slvs515c-197949.pdf) at £2.29 ea this is massively overkill output wise though at 16.

Does anyone know anything more cost effective?

[thor17]

Well, I don't know, what exactly you want to do...but you said, you are using darlington arrays (instead of MOSFETs what I'd prefer), so I guess your project is some kind of a fun project so you want to use inexpensive parts.
Why don't you use just shift registers? A 74HC595 does cost only something around 10cents. If you want to drive just a small LED matrix or something like this, you can drive the LEDs directly with the shift registers (using a resistor to limit the maximum current of course). You can make a software PWM.
The TLC5940 is good, but do you really need a 16-Bit PWM? Another good IC for driving LEDs is the HT1632C, it can drive up to 384 LEDs. Each output does support a 4-Bit PWM.

[st2000]

Found this chip:
http://auschristmaslighting.com/wiki_source/images/b/ba/WS2811.pdf
On the back of this assembly:
http://www.adafruit.com/index.php?main_page=popup_image_additional&pID=1060&pic=2&products_image_large_additional=images/large/1060quattro_LRG.jpg
Looks like you can buy that assembly here:
http://www.adafruit.com/products/1060
Don't know if they will sell you just the chip.

-good luck

@thor17, That's a cool chip (HT1632C). I'm going to cross post it to this thread (but I think the guy is going to go with individual LED controls / not a matrix):
http://forums.hackaday.com/viewtopic.php?f=2&t=3057