TLC5940NT in Parallel

Discussion in 'General Electronics Chat' started by slisgrinder, Jun 21, 2009.

  1. slisgrinder

    Thread Starter Active Member

    Dec 7, 2008
    Hey guys,

    I was wondering if I could put 3 TLC5940s in parallel with all pins in parallel (like stacking the TLC5940s on top of each other) to provide high current sinking?

    I have been looking at some literature that I have attached from TI but it only shows the output pins in parallel which complicates the programming in arduino.
  2. SgtWookie


    Jul 17, 2007
    I'm not familiar with that particular IC, but from the Application Report you attached, it appears to be simply a linear current regulator, achieved via multiple current mirrors.

    While it would be fairly inexpensive to implement, it would not be very efficient, particularly for high-power LEDs. There would be a good bit of power dissipated in the IC itself.

    I'd recommend against "stacking" these ICs, as you would wind up with a very hot stack.

    What is it that you're attempting to accomplish?
  3. slisgrinder

    Thread Starter Active Member

    Dec 7, 2008
    I am implementing a larger scaled version of the following:

    I did it in a small scale and it worked, and now I am expanding it to my existing set of 1 watt leds. These leds require 350ma of current but since the IC can only deliver 120ma of current per channel, I thought better to have 3 of them in parallel to supply 360ma of current...