af8e7e236b
Added gnuplot to the EDA container; sims now wrdata their curves and plots.gp renders 5 PNGs in hardware/eda/sim/plots/ (open in any browser/viewer): - input_loading: instrument(1M) preserves the +16dB pickup resonance the line(25k) flattens - stage1_cmrr: common-mode leakage, 0.1% vs 1% resistor mismatch - stage2_recon: DAC reconstruction filter (flat to 20k, -3dB ~75k) - stage4_driver: balanced differential response (flat across audio) - stage1_phantom: +48V transient clamped at the op-amp input, decays to ~0 (.data intermediates git-ignored.) Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
39 lines
1.7 KiB
Gnuplot
39 lines
1.7 KiB
Gnuplot
# Render the PM_K-1 ngspice simulation data to PNG plots.
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# Run inside the container AFTER the sims have written their .data files:
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# ./run.sh bash -lc 'cd /work/hardware/kicad; for s in ...; do ngspice -b ../eda/sim/$s.cir; done; gnuplot /work/hardware/eda/sim/plots.gp'
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set terminal pngcairo size 1000,560 font "Sans,11"
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set grid
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set key box
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P = "/work/hardware/eda/sim/plots/"
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set logscale x
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set xlabel "Frequency (Hz)"
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set output P."input_loading.png"
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set title "Input loading: line (25k) vs instrument (1M) input -- why Hi-Z preserves the pickup"
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set ylabel "Level (dB)"
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plot "/work/hardware/eda/sim/input_loading.csv" u 1:2 w l lw 2 t "line input (25k ohm)", \
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"" u 3:4 w l lw 2 t "instrument input (1M ohm)"
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set output P."stage1_cmrr.png"
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set title "Stage 1 receiver: common-mode leakage vs resistor match (lower = better; perfect match ~ -inf, off scale)"
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set ylabel "Output leakage (dB, Vcm = 1V)"
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plot P."stage1_cmrr.data" u 1:2 w l lw 2 t "0.1% mismatch", \
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"" u 3:4 w l lw 2 t "1% mismatch"
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set output P."stage2_recon.png"
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set title "Stage 2 DAC reconstruction filter -- flat to 20 kHz, -3 dB near 75 kHz"
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set ylabel "Gain (dB)"
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plot P."stage2_recon.data" u 1:2 w l lw 2 t "filter response"
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set output P."stage4_driver.png"
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set title "Stage 4 balanced output -- differential response (flat across the audio band)"
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set ylabel "Differential gain (dB)"
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plot P."stage4_driver.data" u 1:2 w l lw 2 t "hot - cold differential"
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unset logscale x
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set output P."stage1_phantom.png"
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set title "Stage 1 protection: +48V phantom hit at the op-amp input -- clamped, then decays to ~0"
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set xlabel "Time (s)"
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set ylabel "Op-amp input (V)"
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plot P."stage1_phantom.data" u 1:2 w l lw 2 t "V(op-amp input)"
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