I have a DC load circuit using IRFP7530PBF. It is simple design as follow:
- The gate of the MOSFET have a 10K resistor to ground and a DAC (Digital to Analog Converter) generating from 0 to 10 Volts.
- The drain have a shunt resistor and the other end of the resistor go to 12 Volts.
- The source go to ground.

When the voltage of the DAC reach around 4.7XX volts (which is connected to MOSFET gate) allow us a 6 to 8 amps to flow through the drain of the MOSFET. Under this
current condition (8 amps) the MOSFET get burned (short circuit drain to source).
According to the spec it is a 195A but we cannot get it to pass 8 amps. If we use the same circuits, but replace the MOSFET for IRFP064NPBF
I have not problem at all, we were able to run up to 25 amps without issue with MOSFET IRFP064NPBF.
The reason we want to use IRFP7530PBF is because of the current and power dissipation. We do not allow power device, in our design,
to use more than 20% of their capacity to avoid rapid degradation with the heat over time and we need to reach around 35 amps.

Is there a specs we are overlooking for IRFP7530PBF different than IRFP064NPBF that cause our circuit design to fail when the current flow reach around 8 amps ?

Any help is welcome.

Thanks
Francisco Cruz