2019/7/2 learning summary

2019/7/2 learning summary

1 Analog circuit part

1.1 Use MOSFET to make amplifier

1.1.1 CS amplifier

DC bias circuit provides stable $V_G$
Use

• $I_D=\frac{1}{2}{k}_n^{{}^{\prime }}\frac{W}{L}(V_{GS}-V_t{)}^2$
• $V_{GS}=V_G-V_S$

Can find unknown parameters in the circuit.
Features:

• Very high input resistance
• Not low output resistance
• The voltage gain is moderate, but the effective swing of small AC signals is small

1.1.2 CD amplifier

• Voltage gain less than 1 but close to 1
• Very high input resistance
• Very low output resistance
• When $R_i\left(Inputtheelectricalresistance\right)>>R_{the}\left(Outputanelectricalresistance\right)(the\; mostgoodis{R}_{the}=0,R_i=\infty )$ , can be made into voltage follower.

1.1.3 CG amplifier

• Moderate voltage gain, very low source voltage gain
• Very low input resistance
• Not low output resistance
• When $R_D\left(Theelectricresistance\right)>>R_L\left(Negativecarrier\right)$ , the current follower can be made.

1.2 PCB production, printing and etching

Will be completed soon.