... or RC filter
I'll address these both at the same time...
Why do you need non-inverting level translator? You cannot invert in SW?
Are you sure the input sees the ringing? Maybe it is scope artifact due to long GND leads?
Frequency of the oscillations is about 6 MHz; period 160 ns. Interesting fact: the blue trace (MCU output?) is lagging the yellow trace ringing by a tiny bit but consistently. Maybe 5 - 10 ns? I have no idea what that means. Can you make a photo of your setup?
I've tried the RC filter, again, it pushes the timing uncomfortably close. Haven't dont the RL or RLC circuit yet, wifey got home from work and it was midnight haha. But yes, I made the same measurement. And I did experiment with some more values after making some calculations. I can critically damp for 12 MHz to get most of the ring out. Just a -600mV undershoot and a 100mv overshoot and no more ring.
I believe that the lagging ring on input is coming from the transition between conduction and the reverse bias of the transistor/diode clamp.
As for ground, I do have the lead connected to power supply ground. The scopes waveform output is driving the input to channel A and the circuit. Ie, 3.3v input is where the signal and channel a are probed to. No ground loops either, the scopes grounds are all the same so the same lead the supplies signal is the scope ground...
Yes, this is one case where a photo could give us more info than a schematic.
Keep ground wires short ... all going to one point near or at the power source (star grounding scheme is the best.
If using a breadboard, use some caps across the power rails (one large i.e. 10uF+, one small 0.1uF).
It looks to me that the circuit is an inverting level shifter, but the traces look to be nearly in phase, so how is the scope configured, i.e. trigger levels for each channel?
Do your scope probes have x10 switch? If so, give it a try and re-adjust mV/div to compensate. The x1 setting will be lower impedance and could introduce much of the ringing.
I have a 1000uf, 220 pf, and 10 pf capacitor in parallel with VCC and ground for power supply isolation. Also, the driven devices are somewhat power hungry. Also note that I don't have the load hooked up while testing the circuit. I'll follow up in a few minutes with new scope data and an image of the hookup.
Lastly, yes, i did try x10. No difference in wave form. That was the very first thing I tried haha