Lots of flashing LEDs: constant current ICs?

Forum 2005-2010 (read only) Hardware Interfacing
1

I'm trying to make a circuit with a lot of LEDs (50-100) flashing in sync with each other. Let's say they'll be on for ~1ms every 25ms.

I have a program working with the right timing, but wonder about the best way to make a circuit to drive that many LEDs with constant but adjustable current, on the order of 10-100mA.

I've used SAA1064s for 7-segment displays, but they don't have enough outputs and have a range of 3-21mA.

Looking for constant current driver ICs, everything I find wants to drive very high power LEDs, but not many medium-to-low power LEDs. Any suggestions would be most appreciated!!

2

I used the following in my 5x5x5 led cube project. 16 bit constant current serial in and you can daisy chain as many in series as you require. One resistor sets the constant current value for the 16 drivers. Avalible in DIP package, I got mine from Newark Electronics.

http://www.allegromicro.com/en/Products/Part_Numbers/6276/index.asp

Lefty

3

What about this one?
PCA9698 from NXP Read about the features. :slight_smile:
sorry no link.

4

Thanks for both suggestions!

A6276's (or newer A6279's) might work better than the PCA9698 (http://www.nxp.com/documents/data_sheet/PCA9698.pdf btw), purely from a max current perspective.