CS stage with current load.

• $A_v$ of single CS amp is $A_v=-gmR_D$. So to increase $A_v$, we need to increase $R_D$. With a resistor or diode connected load, increasing $R_L$ limits output voltage swing more practical approach is to replace limit output.

  

• Here MOS $M_2$ will be acting as a current source.

• $V_b$ should be adjusted such that $M_2$ will be in saturation.
• Voltage gain equation will be $A_v=-gm_1(r_{o1}||r_{o2})$