349
edits
Ocs package: Difference between revisions
→A CMOS AND GATE
| Line 16: | Line 16: | ||
** 6 MOSFETs (3 n-type + 3 p-type) | ** 6 MOSFETs (3 n-type + 3 p-type) | ||
** 3 Voltage sources | ** 3 Voltage sources | ||
For the MOSFETs we use a very simple algebraic model defined by the following code | |||
{{Code|Model evaluator file for simple MOSFET models |<syntaxhighlight lang="octave" style="font-size:13px"> | |||
function [a,b,c] = Mnmosfet (string, parameters, parameternames, extvar, intvar, t) | |||
switch string | |||
case 'simple', | |||
rd = 1e6; | |||
for ii=1:length(parameternames) | |||
eval([parameternames{ii} "=",... | |||
num2str(parameters(ii)) " ;"]) | |||
endfor | |||
vg = extvar(1); | |||
vs = extvar(2); | |||
vd = extvar(3); | |||
vb = extvar(4); | |||
vgs = vg-vs; | |||
vds = vd-vs; | |||
if (vgs < Vth) | |||
gm = 0; | |||
gd = 1/rd; | |||
id = vds*gd; | |||
elseif ((vgs-Vth)>=(vds))&(vds>=0) | |||
id = k*((vgs-Vth)*vds-(vds^2)/2)+vds/rd; | |||
gm = k*vds; | |||
gd = k*(vgs-Vth-vds)+1/rd; | |||
elseif ((vgs-Vth)>=(vds))&(vds<0) | |||
gm = 0; | |||
gd = 1/rd; | |||
id = vds*gd; | |||
else # (i.e. if 0 <= vgs-vth <= vds) | |||
id = k*(vgs-Vth)^2/2+vds/rd; | |||
gm = k*(vgs-Vth); | |||
gd = 1/rd; | |||
endif | |||
a = zeros(4); | |||
b = [ 0 0 0 0; | |||
-gm (gm+gd) -gd 0; | |||
gm -(gm+gd) gd 0; | |||
0 0 0 0]; | |||
c = [0 -id id 0]'; | |||
break; | |||
otherwise | |||
error(["Mnmosfet: unknown option " string]); | |||
endswitch | |||
endfunction | |||
</syntaxhighlight> | |||
}} | |||
The model for the p-type devices is entirely analogous. | |||
Below we show three methods for constructing the circuit data structure | Below we show three methods for constructing the circuit data structure | ||