@rdtsc thanks great information, I never thought CMOS inputs as a capacitor. I am using 75176 as transmitter, but the gate charge is not mentioned in datasheet. I think the 75176 is pretty slow enough to not have EMI or SI issues. The problem is the track that is coming from microcontroller to 75176 is long and densely packed with other tracks where the most SI potential issues arise. So I guess putting resistors between then seems like a good bet

@NickAlexeev I will be using 75176, seems decent for the job, what say?

My bad theres actually an EL0631 optoisolator between 75176 and microcontroller . So basically 0 game capacitance.

*gate

I think that resistor based slew rate control won’t work here or will it?

How I about I put a capacitor near the optocoupler and make it an RC filter, how does that sound?