• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 63 subscribers
  • Views 419 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TLC5951 - Dimming a sign

A Train
Prodigy 535 points
Other Parts Discussed in Thread: TLC5951

I have a customer with the following question:

We make amber LED highway signs. We normally dim our signa at night. We are going to use the TLC5951 for a new full color sign. To dim the sign can we PWM the XBLNK signal when the ICs are in Auto Display Reapeat Mode? Is it better to pause for different legnths between loading the GS register and clocking the 3 GS registers?

Can you advise?

  • 0
    TI__Mastermind 36110 points

    For overall dimming, I suggest using the Global Brightness function.  This functionality is designed to dim the overall sign.  You can not use the XBLNK pin for this function because XBLNK resets all grayscale counters when low.

  • 0 in reply to Matthew Day
    TI__Prodigy 535 points

    We still need to know if we can externally drive the XBLNK pin when the part is in auto-repeat mode.  We plan to run the counters pretty fast, with hundreds (?) of auto-repeat cycles every 4 milliseconds.  If the counters are reset by externally-driven XBLNK once every 100 or so auto-repeat cycles, I can’t see one “shorted” cycle every 4 milliseconds being an issue.