Forum Rule: Always post complete source code & details to reproduce any issue!
Results 1 to 2 of 2

Thread: PCB design comments: 4x TLC59711 + Teensy

  1. #1

    PCB design comments: 4x TLC59711 + Teensy

    Hello,

    I'd greatly appreciate any suggestions if someone's willing to take a moment.

    I'm making a breakout board for the TLC59711 with 4 of them plus a Teensy 3.1 as a microcontroller. I've created the schematic and pcb in Eagle (attached), and I'd appreciate a more experienced eye on them. Find any errors? Any suggestions on board layout? The idea is to use the TLC59711s as LED controllers. (I realize there are other ways to control LEDs that are easier but for this project I need to perform very smooth, low level fades, and because of this I need the 16-bit resolution to avoid stair-stepping the lowest light levels.)

    Thanks,

    Andrew

    PCB both layers:
    Click image for larger version. 

Name:	Screen Shot 2015-04-09 at 9.49.38 AM.png 
Views:	251 
Size:	108.0 KB 
ID:	4057

    PCB top layer:
    Click image for larger version. 

Name:	Screen Shot 2015-04-09 at 9.49.28 AM.png 
Views:	174 
Size:	96.7 KB 
ID:	4058

    PCB bottom layer:
    Click image for larger version. 

Name:	Screen Shot 2015-04-09 at 9.49.15 AM.png 
Views:	166 
Size:	91.6 KB 
ID:	4059
    Attached Files Attached Files

  2. #2
    Junior Member
    Join Date
    Jan 2020
    Posts
    1

    SPI Signal Degradation

    Did you have any luck with this PCB design?

    I threw your files in with another order I sent to PCBWay and got it running but only to the first TLC59711 chip. The SPI signal degrades badly from chip to chip. The signal to the second chip is half height with spikes at the end of the square wave and by the third chip it is only spikes with no square wave whatsoever.

    I was thinking it might be the power plane right next to the SPI lines, but I don't have a ton of experience. Any reason you put that on top instead of GND?

    Thanks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •