I am trying to solve a Sedra/Smith problem involving NMOS transistors. Given that both transistors are biased at the same point. Question is to find \$g_{m2}, i_d, v_{d1}\$ and the value of \$R_D\$ for which \$v_o\$ is pulses of amplitude 1V.
However I can't manage to find the value of the voltage pulses at the drain of \$Q_1\$ I actually found the solution manual for the corresponding text book, however I think that the solution is not well implemented as it suggest that the solution would be determined by: $$V_{D_1}=i_{D_1}50\Omega$$ which have no sense.
Best Answer
We have to find out \$g_{m2}, i_d, v_{d1}\$ and \$R_D\$.
Since \$R_{i2} = 1/g_{m2} = 50\Omega,\$ \$g_{m2} = 0.02\mho\$.
Since both transistors are biased at the same point, \$g_{m1} = g_{m2}\$.
$$i_d = g_{m1}v_i = 0.1 mA$$ now, $$v_{d1} = i_d\times 1/g_{m1}=i_d\times 50\Omega$$
Now the equation in solution manual makes sense. I think you can do the rest your own.