The current of gate ig oscillates

BLNKER

I use C3M0075120D as the switch device in the buck converter. It is found that the gate current oscillates, and the peak value of current oscillation increases with the increase of bus voltage. When the bus voltage is not added, there is no gate current oscillation phenomenon. Channel 3 in the figure below is the gate current waveform,and 50mv stands for 1A. That is, the grid current in the oscillation reaches 3A.Channel 4 in the figure below is the gate voltage Vgs waveform.

Forum_Moderator

Thank you for your post, it has been approved and we will respond as soon as possible.

Julius_R

Greetings:

So that we can best assist you, we will need some more information about your circuit.

1. Are you just driving one MOSFET? Any paralleled?
2. What is the value for your gate resistors? Is there any capacitance installed across the gate and source? We don't recommend any for the TO-247-3L package devices.
3. What are you using to drive the gate of the MOSFET? How far is the gate driver from the device in your layout?
4. Can you share any details about your layout? Is the source return a plane or traces? Is the gate and source trace/plane overlapping on adjacent layers or at least routed side by side?

Anything you can share on your schematic or layout will be helpful in solving your problem.

Julius

TBhatia

Hi, I hope that this answered your question. I will close this discussion for now but if you have a follow up question, please "Start a New Discussion" and we would be glad to support you further.