6.3inch 4 lossy lines LTRA model -- R load Ra 1 2 1K Rb 0 3 1K Rc 0 4 1K Rd 0 5 1K Re 6 0 1Meg Rf 7 0 1Meg Rg 8 0 1Meg Rh 9 0 1Meg * * Subcircuit test * test is a subcircuit that models a 4-conductor transmission line with * the following parameters: l=9e-09, c=2.9e-13, r=0.3, g=0, * inductive_coeff_of_coupling k=0.6, inter-line capacitance cm=3e-14, * length=6.3. Derived parameters are: lm=5.4e-09, ctot=3.5e-13. * * It is important to note that the model is a simplified one - the * following assumptions are made: 1. The self-inductance l, the * self-capacitance ctot (note: not c), the series resistance r and the * parallel capacitance g are the same for all lines, and 2. Each line * is coupled only to the two lines adjacent to it, with the same * coupling parameters cm and lm. The first assumption implies that edge * effects have to be neglected. The utility of these assumptions is * that they make the sL+R and sC+G matrices symmetric, tridiagonal and * Toeplitz, with useful consequences (see "Efficient Transient * Simulation of Lossy Interconnect", by J.S. Roychowdhury and * D.O Pederson, Proc. DAC 91). * It may be noted that a symmetric two-conductor line is * represented accurately by this model. * Subckt node convention: * * |--------------------------| * 1-----| |-----n+1 * 2-----| |-----n+2 * : | n-wire multiconductor | : * : | line | : * n-1-----|(node 0=common gnd plane) |-----2n-1 * n-----| |-----2n * |--------------------------| * Lossy line models .model mod1_test ltra rel=1.2 nocontrol r=0.3 l=2.62616456193e-10 g=0 c=3.98541019688e-13 len=6.3 .model mod2_test ltra rel=1.2 nocontrol r=0.3 l=5.662616446e-09 g=0 c=3.68541019744e-13 len=6.3 .model mod3_test ltra rel=1.2 nocontrol r=0.3 l=1.23373835171e-08 g=0 c=3.3145898046e-13 len=6.3 .model mod4_test ltra rel=1.2 nocontrol r=0.3 l=1.7737383521e-08 g=0 c=3.01458980439e-13 len=6.3 * subcircuit m_test - modal transformation network for test .subckt m_test 1 2 3 4 5 6 7 8 v1 9 0 0v v2 10 0 0v v3 11 0 0v v4 12 0 0v f1 0 5 v1 0.371748033738 f2 0 5 v2 -0.601500954587 f3 0 5 v3 0.601500954587 f4 0 5 v4 -0.371748036544 f5 0 6 v1 0.60150095443 f6 0 6 v2 -0.371748035044 f7 0 6 v3 -0.371748030937 f8 0 6 v4 0.601500957402 f9 0 7 v1 0.601500954079 f10 0 7 v2 0.37174803072 f11 0 7 v3 -0.371748038935 f12 0 7 v4 -0.601500955482 f13 0 8 v1 0.371748035626 f14 0 8 v2 0.601500956073 f15 0 8 v3 0.601500954504 f16 0 8 v4 0.371748032386 e1 13 9 5 0 0.371748033909 e2 14 13 6 0 0.601500954587 e3 15 14 7 0 0.601500955639 e4 1 15 8 0 0.371748036664 e5 16 10 5 0 -0.60150095443 e6 17 16 6 0 -0.371748035843 e7 18 17 7 0 0.371748032386 e8 2 18 8 0 0.601500957319 e9 19 11 5 0 0.601500955131 e10 20 19 6 0 -0.371748032169 e11 21 20 7 0 -0.371748037896 e12 3 21 8 0 0.601500954513 e13 22 12 5 0 -0.371748035746 e14 23 22 6 0 0.60150095599 e15 24 23 7 0 -0.601500953534 e16 4 24 8 0 0.371748029317 .ends m_test * Subckt test .subckt test 1 2 3 4 5 6 7 8 x1 1 2 3 4 9 10 11 12 m_test o1 9 0 13 0 mod1_test o2 10 0 14 0 mod2_test o3 11 0 15 0 mod3_test o4 12 0 16 0 mod4_test x2 5 6 7 8 13 14 15 16 m_test .ends test * x1 2 3 4 5 6 7 8 9 test * * VS1 1 0 PWL(15.9NS 0.0 16.1Ns 5.0 31.9Ns 5.0 32.1Ns 0.0) .control TRAN 0.2NS 50NS plot v(1) v(2) v(6) v(7) v(8) v(9) .endc * .END
