spice_test_suite/plot_bipolar_iv.py

#!/usr/bin/env python3
#
# Plot Bipolar I/V curve from devicename + '__vth.data' from running ngspice
# on 'bipolar_test.spice'

import os
import sys
import matplotlib.pyplot as plt


def make_bipolar_iv_plot(devicepath, devicename, version, corner):

    with open(devicepath + '/' + devicename + '__vth.data', 'r') as ifile:
        idata = ifile.read().split()

    # Reformat data

    nrows = int(len(idata) / 6)
    allIce = list(float(idata[p + 1]) for p in range(0, len(idata), 6))
    allVbe = list(float(idata[p + 3]) for p in range(0, len(idata), 6))
    allVce = list(float(idata[p + 5]) for p in range(0, len(idata), 6))

    # Generate X/Y plots

    plt.figure()
    for i in range(0, len(allIce), 181 * 10):
        Ice = allIce[i : i + 181]
        Vbe = allVbe[i : i + 181]
        Vce = allVce[i : i + 181]
        plt.plot(Vce, Ice)

    title = 'SkyWater sky130 PDK ' + version + ' ' + devicename + ' I/V characteristic (Ice vs. Vce) at corner ' + corner
    plt.title(title)
    plt.xlabel('Vce (V)')
    plt.ylabel('Ice (A)')
    plt.axis('on')
    plt.grid('on')
    plt.savefig(devicepath + '/' + devicename + '_ice_v_vce.svg')

    plt.figure()
    for i in range(0, 181, 18):
        Ice = allIce[i : len(allIce): 181]
        Vbe = allVbe[i : len(allVbe): 181]
        Vce = allVce[i : len(allVce): 181]
        plt.plot(Vbe, Ice)

    title = 'SkyWater sky130 PDK ' + version + ' ' + devicename + ' I/V characteristic (Ice vs. Vbe) at corner ' + corner
    plt.title(title)
    plt.xlabel('Vbe (V)')
    plt.ylabel('Ice (A)')
    plt.axis('on')
    plt.grid('on')
    plt.savefig(devicepath + '/' + devicename + '_ice_v_vbe.svg')


if __name__ == '__main__':
    if len(sys.argv) < 2:
        print("No device name given to plot_bipolar_iv")
        sys.exit(1)

    devicename = sys.argv[1]
    make_bipolar_iv_plot(os.getcwd(), devicename, version, corner)