AN3984 datasheet(31/46 Pages) STMICROELECTRONICS

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AN3984

Matlab code (functions)

Doc ID 022240 Rev 1

31/46

CosTeta = cos(Teta);

Normalized Gain

NormGain = 10^(Gain/40);

alpha and beta

alpha = (SinTeta/2)*sqrt((NormGain+(1/NormGain))*(1.0/Slope-1.0)+2.0);

beta = 2*sqrt(NormGain)*alpha;

%% Coefficient Calculation

if FType == 0

FType = 0 => LowShelf

b0 = NormGain*((NormGain+1)-(NormGain-1)*CosTeta + beta);

b1 = 2*NormGain*((NormGain-1)-(NormGain+1)*CosTeta);

b2 = NormGain*((NormGain+1)-(NormGain-1)*CosTeta - beta);

a0 = (NormGain+1)+(NormGain-1)*CosTeta + beta;

a1 = -2*((NormGain-1)+(NormGain+1)*CosTeta);

a2 = (NormGain+1)+(NormGain-1)*CosTeta-beta;

else

FType = 1 => HighShelf

b0 = NormGain*((NormGain+1)+(NormGain-1)*CosTeta + beta);

b1 = -2*NormGain*((NormGain-1)+(NormGain+1)*CosTeta);

b2 = NormGain*((NormGain+1)+(NormGain-1)*CosTeta - beta);

a0 = (NormGain+1)-(NormGain-1)*CosTeta + beta;

a1 = 2*((NormGain-1)-(NormGain+1)*CosTeta);

a2 = (NormGain+1)-(NormGain-1)*CosTeta-beta;

end

APW Coefficient - Reworked coefficient

Coeff_0 = (b1/2.0)/a0;

Coeff_1 = (b2)/a0;

Coeff_2 = (-a1/2.0)/a0;

Coeff_3 = (-a2)/a0;

Coeff_4 = (b0/2.0)/a0;

AN3984 Datasheet(PDF) 31 Page - STMicroelectronics