Answers for tutorial 8:

1. - I_0 R_C tanh(v/v_T)
2. (a) Differential mode gain is -gm(R || rdsn || rdsp)
   Common mode gain is approximately -1/(2 gmp R0) where R0 is the output resistance of the current source.
   (b) Differential mode gain is approximately -rdsp / R.
   Common mode gain is approximately -rdsp/(R + 2 R0) where R0 is the output resistance of the current source.
3. v_{out} / (v_1 - v_2) = gmn rdsn \frac{rdsp (1 + gmp(1/gmp || rdsp))}{2 rdsp + 2 rdsn}
   v_{out} / (v_1 + v_2) = 0; CMRR = infinite because common mode gain is 0.