Hello, I have some questions about the transfer characteristics in the CAS480M12HM3 data sheet.
(1) How were the transfer characteristic curves in the datasheet obtained?

(2) When I measured the transfer characteristics using the Tektronix B1505A, the measured data differed significantly from the data in the datasheet. As shown in the following figure (with the same measurement conditions, temperature at 25℃, pulse width of 300us, and drain-source voltage of 20V), I initially suspected that it was caused by the self-heating effect of the device. So, I measured a single point separately on the interface for measuring transfer characteristics. It can be seen that when the drain-source voltage is 17.8766V and the gate-source voltage is 5.99996V, the drain-source current is 291.17A, and there is also a significant difference from the datasheet. What is the reason for this?

These two issues are particularly important to me. I hope to receive your reply. Thank you.