init

Author: scivision

.gitignore

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+*.out

LV.net

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+* Red Pitaya Analog Input
+* https://wiki.redpitaya.com/tmp/Fast_analog_inputs_sch.png
+* https://forum.redpitaya.com/viewtopic.php?f=9&t=468
+
+C200 Vin  Vout 6.8p
+C3   Vin  Vout 10p
+R3   Vin  Vout 499k
+R5   Vin  0    499k
+C206 Vout 0    10p
+
+RL Vout 0 500K
+
+*------- test source ------------
+* source resistance
+Rs Vs Vin 50
+
+* transient
+* V_V1 Vs 0 sin(0.0 1 50MEG 0 0) 
+
+* AC freq sweep
+V_V1 Vs 0 dc 0. ac 1. sin(0. 1. 100MEG 0 0) 
+
+
+*V_V1 Vin 0 pulse(-0.5 0.5 0 0.1u 0.1u 4.8u 10u)
+
+*--------- freq sweep -------------------------------------
+.print ac v(Vin) v(Vout)
+.AC DEC 200 100 50MEG  > LV.out 
+
+*--------- transient ----------------
+* .print selects quantities to output
+.print tran v(Vin) v(Vout)
+*gnucap
+*.tran 0.1u 10u 0 trace all > LV.out 
+
+*ngspice
+*.tran 1u 100u 0 
+
+.END

PlotTransfer.py

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+#!/usr/bin/env python
+from pathlib import Path
+from numpy import loadtxt,log10
+from matplotlib.pyplot import figure,show
+import seaborn
+seaborn.set_style('whitegrid')
+
+fn = Path('LV.out')
+
+
+dat = loadtxt(fn)
+
+T = dat[:,2]/dat[:,1]
+#%%
+ax = figure().gca()
+ax.plot(dat[:,0], 20*log10(T))
+ax.set_xlabel('frequency [Hz]')
+ax.set_ylabel('gain [dB]')
+ax.set_title(f'{fn.stem} Transfer Function $H(f)$')
+ax.autoscale(True,axis='x',tight=True)
+ax.set_xscale('log')

README.md

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 # red-pitaya-analog-input-model
 Red Pitaya analog input SPICE model (GNUcap/ngSPICE compatible)
+
+## Run Simulation
+
+    gnucap -b LV.net
+
+## Plot Simulation output
+
+    ./PlotTransfer.py