ADUM3220 Gate driver floating supply

Hi,

I have a question about a testing set up that I am implementing using ADUM3220 evaluation board. I have a full bridge of MOSFETs to implement LLC Converter, the input DC bus can go up to 400 v the output after the transformer is 48 v dc and the power is 350 Watt.

I am using three different power supplies (E3630A ) form Keysight, two of them to power the two high side gate voltages and one for the low side switches.

When I start increasing the dc bus higher than 50 v , the gate driver power supply reading (E3630A ) goes up.

I connect the oscilloscope across the power supply but I still can see the constant 15 volt of the gate driver even though the digital reading on the power supply is different.

Any idea on what is happening?

Regards 

Parents Reply Children
No Data