Original question:
Dear team,
My customer referred to our LMG1020EVM-006 user guide and found that in Figure7 to 10 the ringing of IN+ and Vg are much larger than their expectation. Is this because of the parasitic inductance of the PCB or from the probe? Can we reduce the ringing? Thanks.
BR,
Rory
Hi Rory,
thanks for reaching out about the LMG1020 EVM, sorry for the late reply.
Is the ringing in the users guide larger or smaller than the ringing seen on the bench? Can you share the waveforms of IN+ and Vg? are you probing with the pig tail method?
Typically Vg loop inductance will ring a bit with the probe and gate capacitance since they are on a similar scale. And since the rise times have a high bandwidth seeing some ringing is expected with high resonant frequency gate or power loops. The ringing on these points can be either from the probe or the pcb. An example of probe ringing can be found in the LMG1020 TIDA (
) on page 13. The expected probe inductance can be seen in the oscillations of the ringing. However if the power loop is seeing large oscillations on the cathode waveform its possible the ringing is from the power loop inductance and being coupled to the gate and input signals.
thanks,
