SIC MOSFET Overstress

[Johnsoncheah]

Hi Team,

Customer had IMW120R060M1H to replace wolfspeed C2M0080120D.

Customer have questions below question would like to clarify.

• From the graph below, the gate resistor is 100ohm. The negative current is around -0.8A. However, the MOSFET is very hot. They have tested with 10ohm gate resistor, but the negative current up to -2.3A observed. Will negative current spike of 2.3A cause any reliability issue to the SIC MOSFET?
• What is the max negative current the SIC MOSFET can sustain?
• If the negative current will cause reliability issue, how to improve the ringing?

The brightness below refers to the load level. 100% Brightness = full load, 10% Brightness =light load

Customer is using flyback controller to drive the SIC MOSFET.

MOSFET Waveform (Ch1=Vds, Ch2=Vgs, Ch4=Ids)

Fig.1 : 100% Brightness

Fig.2 : 40% Brightness

Fig.3 : 30% Brightness

Fig.1 : 20% Brightness

Fig.4 : 10% Brightness

Schematic (Output 350W 500V 700mA)

[AZIZ_HASSAN · Accepted solution]

Hi,

Thank you for posting at Infineon community.

1) Can you please share the complete schematics especially gate circuit and secondary side circuit.

2) May I know why did you put C3 of 10Pf .

BR,

AZIZ HASSAN

[AZIZ_HASSAN]

Hi,

Can you please update the status.

BR,

AZIZ

[AZIZ_HASSAN]

Hi,

Any updates please.

BR,

AZIZ