write_spice_file.m

均衡器的参数设置,设置不同的参数

%% write_spice_file.m
%%
% This function generates a SPICE .cir file. To trace the output of all
% the filters in SPICE, trace something like VDB(51) + VDB(52) + ... +
% VDB(510)+....  The w0 and n inputs are also needed. The function doesn't
% return anything.

function write_spice_file(r1,r2,r5,c3,c4,w0,n)
%%
%% Header
%%
%%
% These lines are responsible for creating a SPICE voltage source, and
% definining a subcircuit which will be used for all of the OP AMPS in the
% equalizer.  The SPICE file is written into the directory defined by
% MatLab's cd.


    file_1 = fopen(strcat(cd,'/EQ_gen_spice_output.cir'),'wt');
    fprintf(file_1,'EQgenerator SPICE OUTPUT\n');
    fprintf(file_1,'VS	1	0	AC	1 \n');
    fprintf(file_1,'.SUBCKT OPAMP 1 2 3\n');
    fprintf(file_1,'RI	1	2 	100MEG\n');
    fprintf(file_1,'EA	3	0	1	2	100MEG\n');
    fprintf(file_1,'.ENDS OPAMP\n');
%%

%% Creating the Equalizer in SPICE
%%
% For each filter, the appropriate SPICE lines are written.  Circuit
% element names are a combination of their name in terms of the multiple
% feedback filter topology and the current filter being written.  For
% example, R12 is R1 in the second filter of equalizer.  Node names are
% created in a similar fashion.  

    for filter_n = 1:n
        
        %write spice comment indicating which filter we're on
        s = sprintf('*Center Frequency: f0 =  %d\n', w0(filter_n)/(2*pi));
        fprintf(file_1,s);
        
        index_n = num2str(filter_n);
        
        %write the r1 line of the current filter
        
        r1_value = sprintf('   %d    ',r1(filter_n));
        node_1 = sprintf('    %d     ',1);
        node_2 = strcat('2',num2str(index_n));
        node_2 = sprintf('    %d     ', str2double(node_2));
        s = strcat('R1',index_n,node_1,node_2,r1_value,'\n');
        fprintf(file_1,s);
        
        %write the r2 line of the current filter
       
        r2_value = sprintf('   %d    ',r2(filter_n));
        node_1 = strcat('2',num2str(index_n));
        node_1 = sprintf('    %d     ', str2double(node_1));
        node_2 = sprintf('    0      ');
        s = strcat('R2',index_n,node_1,node_2,r2_value,'\n');
        fprintf(file_1,s);
        
       
        %write the c3 line of the current filter
        c3_value = sprintf('   %g    ',c3(filter_n));
        node_1 = strcat('2',num2str(index_n));
        node_1 = sprintf('    %d     ', str2double(node_1));
        node_2 = strcat('3',num2str(index_n));
        node_2 = sprintf('    %d     ', str2double(node_2));
        s = strcat('C3',index_n,node_1,node_2,c3_value,'\n');
        fprintf(file_1,s);
        
        
        %write the c4 line of the current filter
        c4_value = sprintf('   %g    ',c4(filter_n));
        
        node_1 = strcat('2',num2str(index_n));
        node_1 = sprintf('    %d     ', str2double(node_1));
        node_2 = strcat('5',num2str(index_n));
        node_2 = sprintf('    %d     ', str2double(node_2));
        s = strcat('C4',index_n,node_1,node_2,c4_value,'\n');
        fprintf(file_1,s);
        
        
        %write the r5 line of the current filter
        r5_value = sprintf('   %g    ',r5(filter_n));
        node_1 = strcat('3',num2str(index_n));
        node_1 = sprintf('    %d     ', str2double(node_1));
        node_2 = strcat('5',num2str(index_n));
        node_2 = sprintf('    %d     ', str2double(node_2)); 
        s = strcat('R5',index_n,node_1,node_2,r5_value,'\n');
        fprintf(file_1,s);
        
        %write the subcircuit line
        x_value = sprintf('   OPAMP    ');
        node_1 = strcat('3',num2str(index_n));
        node_1 = sprintf('     %d     ', str2double(node_1));
        node_2 = strcat('5',num2str(index_n));
        node_2 = sprintf('    %d     ', str2double(node_2));
        node_0 = sprintf('    %d      ',0);
        s = strcat('X',index_n,node_0,node_1,node_2,x_value,'\n');
        fprintf(file_1,s);
        
        
        
    end
%%

%% Footer
%%
% After the circuit has been completed, the following lines prepare the AC
% analysis and finish up the file.

    low_freq = sprintf('    %g    ',(w0(1)/(2*pi))*.01);
    high_freq = sprintf('    %g   ',(w0(n)/(2*pi))*100);
    s = strcat('.AC DEC 50',low_freq,high_freq,'\n');
    fprintf(file_1,s);
    fprintf(file_1,'.PROBE\n');
    fprintf(file_1,'.END\n');
%%
    


end