Schaltungstechnik

376 6 Funktionsschaltungen mit FETs
architecture Level1_nmos of Mosfet is
-- terminals
terminal n1, n2, n3, n4 : electrical;
-- constants
constant vt : voltage := temp * PHYS_K / PHYS_Q;
constant cox : capacitance := 3.9*PHYS_EPS0/tox;
-- branch quantities
quantity vrd across ird through drain to n1;
quantity vrg across irg through gate to n2;
quantity vrb across irb through bulk to n3;
quantity vrs across irs through source to n4;
quantity vds across ids, irds through n1 to n4;
quantity vgs across icgs through n2 to n4;
quantity vbs across icbs, idbs through n3 to n4;
quantity vbd across icbd, idbd through n3 to n1;
quantity vgd across icgd through n2 to n1;
quantity vgb across icgb through n2 to n3;
-- free quantities
quantity vth : voltage := 2.586e-2; -- threshold voltage
quantity vsat : voltage; -- saturation voltage
quantity vs : voltage; -- effective surface mobility
quantity leff : real := 100.0e-6; -- effective length
quantity beta : real := 2.0e-5; -- gain
quantity cb2s, cb2d : capacitance := 1.0; -- capacitances
quantity cgs, cgd, cgb : capacitance := 1.0; -- capacitances
begin
-- some free quantity calculations
if vbs