Matrix user forums

Hi Guys,
I've had a quick trawl in the usual places... Im looking for a multi channel LED driver chip, that provides individual PWM outputs and controlled by SPI.
Most of the chips I have found are i2C but I'd prefer SPI as I use the SPI for the CAN module.
A 16 channel chip with individual 8 bit PWM on each output would allow complete RGB and brightness control of 4 Leds
Thanks for any pointers. J.

Hello,

A quick Google search came up with the following. No idea on pricing.

http://www.national.com/pf/LP/LP55281.html#Overview

It may be cheaper to use say a PIC in SPI slave mode and do the PWM via a timer interrupt.

Found the part on Digikey, however the IC is a ball grid array. How are your SMD skills?

This could be another option.

http://hackaday.com/2009/06/29/parts-sh ... ule-a6281/

I used this text for my Google search.

SPI RGB LED Driver

Cheers Ben,
I'll have a look at those when I get to get out of this damn airport and to the hotel.
I did do a google search on much the same terms (honest ) but most datasheets seem to be for devices running I2C or some alternative form of serial....and I want to stick to a standard (flowcode supported) serial comms for now and SPI is preferred as I'm using in other commonly used blocks. I'll have a good 'ol read up and see how the idea develops.
Thanks, J.

Hello Jay Dee,

Have you looked at the TLC5940 made by Texas Instruments? 16 CHANNEL LED DRIVER WITH DOT CORRECTION AND GRAYSCALE PWM CONTROL. Available on eBay.

Regards

JAW

Thanks JAW, its quite a beestie. Reasonable price £2-3 from farnell and not in BGA. I've saved the datasheet and will have a proper look through later. I'd love to look more at my LED project but its just finding time...hmm.