Capacitance characteristics of Ciss, Crss and Coss are important factors affecting switching characteristics of MOSFET.
Ciss: input capacitance (Ciss = Cgd + Cgs)
⇒Sum of gate-drain and gate-source capacitance: It influences delay time; the bigger the Ciss, the longer the delay time.
Crss: Reverse transfer capacitance (Crss = Cgd)
⇒Gate-drain capacitance: The bigger the Crss, the more the characteristic of drain current rising deteriorates, which is disadvantageous for MOSFETs’ loss. Low capacitance is needed to drive at high speed.
Coss: Output capacitance (Coss = Cgd + Cds)
⇒Sum of gate-drain and drain-source capacitance: It influences turn-off characteristic, and loss with light load. In the case of large Coss, turn-off dv/dt decreases, which is advantageous for noise. But loss with light load increases.