Need tool to show digital filter response

Not a 100% serious suggestion maybe, but you might do it in LT Spice. Integrators, summers, quantizers. Might wind up with the same transfer function as the digital version.

Den onsdag den 14. februar 2018 kl. 00.16.18 UTC+1 skrev Klaus Kragelund:

Tim

-- Seven Transistor Labs, LLC Electrical Engineering Consultation and Contract Design Website:

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GNU Octave has it, too:

a scritto:

world

Try Scilab.

Bye Jack

Put in an impulse, FFT, gnuplot.

Jeroen Belleman

I am doing it right now in Pspice, like the gentleman at this reference:

But, that is the ideal case, so no quantization effects are included. And no easy way to shift between the different digital filter topologies

I was interested in knowing if a tool existed that had all the funny stuff included

Cheers

Klaus

Very nice :-)

The quantizer part is easy:

Version 4 SHEET 1 880 680 WIRE 48 48 0 48 WIRE 112 48 48 48 WIRE 384 48 320 48 WIRE 432 48 384 48 WIRE 0 96 0 48 WIRE 112 112 112 48 WIRE 320 112 320 48 WIRE 432 128 432 48 WIRE 0 224 0 176 WIRE 112 224 112 192 WIRE 320 240 320 192 WIRE 432 240 432 208 FLAG 0 224 0 FLAG 320 240 0 FLAG 112 224 0 FLAG 432 240 0 FLAG 48 48 X FLAG 384 48 OUT SYMBOL bv 320 96 R0 WINDOW 3 36 198 Left 2 SYMATTR Value V=int(5.1*V(X))*0.2 SYMATTR InstName B1 SYMBOL voltage 0 80 R0 WINDOW 3 16 199 Left 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR Value SINE(0 1 1k 0 0 0 3) SYMATTR InstName V1 SYMBOL res 96 96 R0 SYMATTR InstName R1 SYMATTR Value 1k SYMBOL res 416 112 R0 SYMATTR InstName R2 SYMATTR Value 1k TEXT 528 160 Left 2 !.tran 0 .005 0 1u TEXT 560 64 Left 2 ;Quantizer TEXT 568 112 Left 2 ;JL 2015

but Spice is probably better suited to model other topologies, like integrator-based IIR filters. A digital simulation of a biquad or state-variable filter can be very elegant and code/time economical, and tends to have sensible coefficients.