1.砷化镓数字集成电路由晶体管原理可知,逻辑电路的本征开关速度与晶体管的电流增益带宽乘积f_T有关,即t∝1/f_T (1)对于场效应晶体管,f_T=g_m/2πC_(gs) (2)g_m为跨导,C_(gs)为栅源间电容。若场效应管工作在漏极饱和条件下(V_(ds)>V_(gs)-V_p),漏极特性方程为I_(ds)=K(V_(gs)-V_p)~2 (3)式中K=eμ_nW/2aL_g按照跨导的定义可得式中I_(ds)为漏源电流,V_p为沟道夹断电压, Gallium Arsenide Digital Integrated Circuit It is known from the transistor principle that the intrinsic switching speed of the logic circuit is related to the product f_T of the current gain bandwidth of the transistor, ie, tα1 / f_T (1) For a field effect transistor, f_T = g_m / 2πC_ gs) (2) g_m for the transconductance, C_ (gs) is the gate-source capacitance. If the FET works in the drain saturation condition (V ds> V gs) -V_p, the drain characteristic equation is I ds = K V_ gs -V_p ~ In the definition of transconductance K = eμ_nW / 2aL_g where I_ (ds) is the drain-source current, V_p is the channel pinch-off voltage,