MOSFET

Capacitance Calculation

Input capacitance, $$C_{iss} = C_{gs} + C_{gd}$$

Output capacitance, $$C_{oss} = C_{ds} + C_{gd}$$

Feedback capacitance, $$C_{rss} = C_{gd}$$

So, gate-source capacitance $$C_{gs} = C_{iss} - C_{rss}$$