Re: RAMPS for Due!

Quote
uncle_bob
As mentioned earlier ... you probably don't want to get the FET's switching a whole lot faster than half a microsecond or so. There will not be any real gain in power dissipation. The ringing issues will keep power sloshing around for quite a while with fast edges. I don't think we want to get into high current ferrite beads on the leads.

Might be useful to scope all the supplies (12V, 5V, 3.3V) to see how much they drop when you turn on FETs. I did it when I was debugging my ADC issue, and IIRC, 3.3V dropped to about 2.8V when I turned on an extruder heater, taking about 1us. It must be even bigger for bed switching. Presumably this is due to the disturbance on the supply traveling down the regulators.