In an NMOS low side switch the output voltage at drain depends on the operating point decided from the Id-Vds curve and load line.
According to my understanding, for a low side switch with Vds around 0, we need to keep the operating point in triode region. This can be achieved by keeping Vgs-Vt>0 and relatively high load resistance to keep the NMOS in triode region. I hope this is correct?
Further, for my application, I am using NMOS switch for providing ground voltage to a memristor which is connected between Vdd and Drain terminal whose resistance changes during the ON cycle. This leads to a shift in Drain voltage as the memristor is being programmed for desired resistance. The shift is undesired as i need a constant voltage across memristor during this ON cycle.
So my final question is, How can i make a low side switch for this application which will provide a constant Vds with changing load resistance?