2024-02-29 10:24 AM
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?