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February 29, 2024
Question

LED1642 propagation delay or does ST have a led array driver that redrives clock?

  • February 29, 2024
  • 0 replies
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Just want to make sure I'm understanding this correctly as I have not done something like this in a long time.  I am looking at using the LED1642 (LED array driver) in a chain of over 30 devices.  Clock is routed to every chip but SDO gets redriven from each chip.  This causes a propagation delay so each chip will delay via tPLH or tPHL (8min, 15typ, 25max)ns at 3.3V.  I am using 5V so I'm guessing this numbers will increase?  What I should I plan to use for calculations?

Example:
If I use 15ns and have 30 chips in a chain then my delay at the end will be 29*15 = 435ns + board trace delay time, is this correct?  Which means that will limit the max clock speed to <2Mhz?

Does ST offer a led array driver where it redrives clock, which would help eliminate this concern?

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