--- /dev/null
+## Copyright (C) 2006,2007,2008 Carlo de Falco
+##
+## This file is part of:
+## OCS - A Circuit Simulator for Octave
+##
+## OCS is free software; you can redistribute it and/or modify
+## it under the terms of the GNU General Public License as published by
+## the Free Software Foundation.
+##
+## This program is distributed in the hope that it will be useful,
+## but WITHOUT ANY WARRANTY; without even the implied warranty of
+## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+## GNU General Public License for more details.
+##
+## You should have received a copy of the GNU General Public License
+## along with this program (see the file LICENSE); if not,
+## see <http://www.gnu.org/licenses/>.
+##
+## author: Carlo de Falco <cdf _AT_ users.sourceforge.net>
+
+## -*- texinfo -*-
+##
+## @deftypefn{Function File} @
+## {[@var{a},@var{b},@var{c}]=} Mcapacitors(@var{string},@var{parameters},@
+## @var{parameternames},@var{extvar},@var{intvar},@var{t})
+##
+## SBN file implementing models for capacitors.
+##
+## @var{string} is used to select among models. Parameters are listed
+## as inner items. Possible models are:
+##
+## @enumerate
+## @item @var{string} = "LIN" (Linear Capacitor)
+## @itemize @minus
+## @item C -> capacitance value
+## @end itemize
+## @item @var{string} = "MULTICAP" (Multipole Capacitor)
+## @itemize @minus
+## @item C -> capacitance values
+## @end itemize
+## @item @var{string} = "PDE_NMOS" (Drift-Diffusion PDE NMOS capacitor)
+## @itemize @minus
+## @item tbulk -> bulk thickness
+## @item tox -> oxide thickness
+## @item Nnodes -> number of nodes of 1D grid
+## @item Na -> bulk doping
+## @item toll -> absolute tolerance
+## @item maxit -> max iterations number
+## @item Area -> device area
+## @end itemize
+## @end enumerate
+##
+## See the @cite{IFF file format specifications} for details about
+## the output structures.
+##
+## @seealso{prs_iff,asm_initialize_system,asm_build_system}
+## @end deftypefn
+
+function [a,b,c] = Mcapacitors(string,parameters,parameternames,extvar,intvar,t)
+
+ if isempty(intvar)
+ intvar = 0;
+ endif
+
+ switch string
+ ##LCR part
+ case "LIN"
+ for ii=1:length(parameternames)
+ eval([parameternames{ii} "=" num2str(parameters(ii)) ";"])
+ endfor
+
+ a = [0 0 1; 0 0 -1; 0 0 0];
+ b = [0 0 0;0 0 0;-C C 1];
+ c = [0 0 0]';
+ break
+
+ case "MULTICAP"
+
+ n = length(extvar);
+ C = reshape(parameters,n,n);
+
+ a = [zeros(n) eye(n); zeros(n) zeros(n)];
+ b = [zeros(n) zeros(n); -C eye(n)];
+ c = [zeros(2*n,1)]';
+
+ break
+
+ ##NLC part
+ case "PDE_NMOS"
+
+ constants
+
+ tbulk = 1.5e-6;
+ tox = 90e-9;
+ len = tbulk + tox;
+ Nnodes = 300;
+ Na=1e21;
+ toll = 1e-10;
+ maxit = 1000;
+ Area = 1e-12;
+
+ for ii=1:length(parameternames)
+ eval([parameternames{ii} "=" num2str(parameters(ii)) ";"])
+ endfor
+
+ Vg = extvar(1) - extvar(2);
+ q = intvar(1);
+
+ [Q,C]=Mnmoscap(tbulk,tox,Area,Vg,Na,Nnodes,toll,maxit);
+
+ a = [0 0 1; 0 0 -1; 0 0 0];
+ b = [0 0 0;0 0 0;C -C -1];
+ c = [0 0 Q-q]';
+ break
+
+ otherwise
+ error (["unknown section:" string])
+ endswitch
+
+endfunction
+## Non-linear 1D MOS structure.
+## FIXME: requires SECS1D!!!
+function [Q,C]=Mnmoscap(tbulk,tox,Area,Vg,Na,Nnodes,toll,maxit);
+
+ constants
+
+ Nelements = Nnodes - 1;
+ len = tox+tbulk;
+ x = linspace(0,len,Nnodes)';
+ sinodes = find(x<=tbulk);
+ Nsinodes = length(sinodes);
+ NelementsSi = Nsinodes-1;
+ D = - Na* ones(Nsinodes,1);
+ pp = Na ;
+ p = pp* ones(Nsinodes,1);
+ n = (ni^2)./p;
+ Fn = 0*n;
+ Fp = 0*n;
+
+ V = -Phims + Vg * ones(Nnodes,1);
+ V(sinodes) = Fn + Vth*log(n/ni);
+
+ ## Scaling
+ xs = len;
+ ns = norm(D,inf);
+ Din = D/ns;
+ Vs = Vth;
+ xin = x/xs;
+ nin = n/ns;
+ pin = p/ns;
+ Vin = V/Vs;
+ Fnin = (Fn - Vs * log(ni/ns))/Vs;
+ Fpin = (Fp + Vs * log(ni/ns))/Vs;
+
+ l2 = (Vs*esio2)/(q*ns*xs^2)* ones(Nelements,1);
+ l2(1:NelementsSi) = (Vs*esi)/(q*ns*xs^2);
+
+ ## Solution of Nonlinear Poisson equation
+ [V,nout,pout,res,niter] = DDGnlpoisson (xin,sinodes,Vin,nin,...
+ pin,Fnin,Fpin,Din,l2,...
+ toll,maxit,0);
+
+ L = Ucomplap(xin,Nnodes,[],Nelements,l2);
+ C22 = L(end,end);
+ C12 = L(2:end-1,end);
+ C11 = L(2:end-1,2:end-1);
+
+ drdv = zeros(Nnodes,1); drdv(sinodes) = nout + pout;
+ coeff = zeros(Nelements,1); coeff(1:NelementsSi) = 1;
+ M = Ucompmass(xin,Nnodes,[],[],drdv,coeff);
+ C = C22 - C12'*((C11+M(2:end-1,2:end-1))\C12);
+ Q =(C12'*V(2:end-1)+C22*V(end));
+
+ ## Descaling
+ C = Area*C*(q*ns*xs/Vs);
+ Q = Area*Q*(q*ns*xs);
+
+endfunction
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git://git.creatis.insa-lyon.fr / CreaPhase.git / blobdiff