KT201B Transistors silicon epitaxial planar structure of the n-p-n KT201B: The structure of transistor: npn Pk max - Constant collector power dissipation: 150 mW; fgr - Cutoff frequency of current transfer ratio of the transistor for the circuit with common emitter: not less than 10 MHz; Ukbo max - The maximum collector-base voltage for a given reverse current collector and emitter open circuit: 20 V; Uebo max - Maximum voltage emitter-base reverse current at a given emitter and collector open circuit: 20 V; Ik max - The maximum permissible continuous collector current of 20 mA; Ikbo - Reverse collector current - the current through the collector junction reverse voltage for a given collector-base and emitter open output: less than 1 mA; h21e - Static current transfer ratio of the transistor small signal circuits for common-emitter: 30 ... 90; CK - Capacity of the collector junction: no more than 20 pF