You might consider using a 74HC595 on an SPI output/clock module. Then
you can put your PWM signal on the OUTPUT ENABLE and you are set.
Costs 0.25$USD for each 8 signals,
with up to 50mA output.

--Bob A

On Tue, Dec 8, 2009 at 7:01 AM, Harold Hallikainen
<harold@hallikainen.org> wrote:
> I've used the Allegro A6282
> (http://www.allegromicro.com/en/Products/Part_Numbers/6282/index.asp). It
> has a shift register input with parallel latch, then constant current
> sinks for the LEDs. The currents are all set with a single resistor. You
> can vary brightness by either PWM on the OE pin or putting a variable
> voltage on the bottom of the current set resistor (instead of grounding
> it).
>
> Harold
>
>
> --
> FCC Rules Updated Daily at http://www.hallikainen.com - Advertising
> opportunities available!
> --
> http://www.piclist.com PIC/SX FAQ & list archive
> View/change your membership options at
> http://mailman.mit.edu/mailman/listinfo/piclist
>
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist