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PCA9615 / PCA9616 Termination Resistors

Question asked by Rasid Pac on Jan 14, 2020
Latest reply on Jan 16, 2020 by Rasid Pac

When I use the recommended termination resistors in the datasheet of PCA9616 (R1 = 600 Ohm and R2 = 120 Ohm) with CAT5 cable, the system in the attached picture doesn't work (PIDET and READY lines remain high). However, if I change the resistors on the master side to R1 = 390 Ohm and R2 = 100 Ohm as in Sparkfun's design, the communication works and PIDET and READY go low. I haven't tested other resistor combinations yet but will update here as I do.

Does anybody have any input on this?