What are the capacitance characteristics of MOSFET.

C_iss, C_rss and C_oss are all important factors that influence switching characteristic of MOSFET.

• C_iss: input capacitance (C_iss=C_gd+C_gs)
  ⇒Sum of gate-drain and gate-source capacitance. It influences delay time. The greater C_iss, the longer the delay time.
• C_rss: Reverse transfer capacitance (C_rss=C_gd)
  ⇒Gate-drain capacitance. The greater C_rss, the worse the drain current rising characteristics, which is disadvantageous for MOSFETs’ loss. Low capacitance is needed for high-speed driving.
• C_oss: Output capacitance (C_oss=C_gd+C_ds)
  ⇒Sum of gate-drain and drain-source capacitance. It influences turn-off characteristic and loss with light load. The greater C_oss, the lower the turn-off dv/dt, which is advantageous for noise. But loss with light load increases.