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TLC5947: Need an alternate part

Jonah Harley
Prodigy 10 points
Part Number: TLC5947
Other Parts Discussed in Thread: TLC5951, LP5024

Hi,

We have been shipping a board with the TLC5947, but it is now out of stock everywhere I look, and I need to find a substitute.  I see there is a TLC5951, which has the same 24 LED outputs with greyscale control, but additionally has dot correction and brightness color control.  If I could set those both to max brightness and ignore them the TLC5951 seems like a viable substitute, but I don't have any extra digital lines in my microcontroller to handle them.  Could I hardwire the data lines for dot correction and brightness control high, and then share the same clock and latch lines between greyscale, DC and BC?  My thought is that I can then treat the greyscale lines as I do with the TLC5947, and the others will just get written to the max value every time?  Hopefully my question makes sense.  Or perhaps there's another part in stock that would be a better replacement.

Thanks!

  • 0
    TI__Genius 15776 points

    Our expert is OoO , and the team will reply you within this week.

  • 0
    TI__Expert 4160 points

    Hi Jonah, 

    Thanks for providing all the concrete details of your question. TLC5951 can be an alternative solution for TLC5947 as demonstrated. Please double check if you utilize the 4MHz internal oscillator in TLC5947, because TLC5951 only takes external CLK signals. 

    Best Regards,

    Aaron Bing

  • 0 in reply to Aaron Bing
    Prodigy 10 points

    Thank you, Aaron!  I've ordered some to try.  We provide a signal on SCLK so I don't think we're relying on the internal oscillator.  Fingers crossed!

  • 0 in reply to Jonah Harley
    Prodigy 10 points

    Hi Aaron,  

    The more I learn about the TLC5951 the trickier this change looks.  It does appear that I'm using the internal oscillator on the TLC5947, and although I'm struggling to follow the TLC5951 data sheet it appears I will need quite different firmware, even if I try and disable the dot correction and brightness color control in hardware.  Is there any other part you could recommend that would be an easier change?  I have 19 LEDs to drive, with a 20mA max current.  Thanks.

  • 0 in reply to Jonah Harley
    TI__Expert 4160 points

    Hi Jonah, 

    You could use the Quick Search tool to filter out all the desired RGB LED drivers. It seems that you put an emphasis on grayscale control, so that LP5024 might not be the best solution even though it satisfies with the requirement to "drive 19 LEDs with 20mA max current on each channel." 

    Best Regards,

    Aaron Bing