Actually, when i do simple simulation in ltspice. I found that when choosing two different pmos in inverter design. The min voltage can not reach 0 for some pmos. But i do not know which parameter affects the minimum voltage, can someone give me some guidance. Really want to learn from you and thanks! By the way they both use a GaN hemt to replace a nmos the only different is the pmos.
The pmos i use is bss84 and fdc638p which is the 2nd and 4th one.



The pmos i use is bss84 and fdc638p which is the 2nd and 4th one.


