def test_loopanalysis_incorrect_circuit():
cir = SubCircuit()
assert_raises(ValueError, lambda: FeedbackLoopAnalysis(cir))
cir['probe1'] = LoopProbe('out', gnd, 'out_R2', gnd)
cir['probe2'] = LoopProbe('out', gnd, 'out_R2', gnd)
assert_raises(ValueError, lambda: FeedbackLoopAnalysis(cir))
def test_loopanalysis_numeric():
cir = SubCircuit()
cir['A1'] = VCVS(gnd, 'int', 'out', gnd, g = 10)
cir['R1'] = R('in', 'int')
cir['probe'] = LoopProbe('out', gnd, 'out_R2', gnd)
cir['C2'] = C('int', 'out_R2')
cir['VS'] = VS('in', gnd)
ana = FeedbackLoopAnalysis(cir)
res = ana.solve(np.logspace(4,6), complexfreq=True)
print abs(res['loopgain'])
def test_loopanalysis_viiv():
sympy.var('R1 R2 CL A s')
cir = SubCircuit(toolkit=symbolic)
cir['A1'] = VCVS(gnd, 'int', 'out', gnd, g = A, toolkit=symbolic)
cir['R1'] = R('in', 'int', r=R1)
cir['probe'] = LoopProbe('out', gnd, 'out_R2', gnd, toolkit=symbolic)
cir['R2'] = R('int', 'out_R2', r=R2)
cir['VS'] = VS('in', gnd)
ana = FeedbackLoopAnalysis(cir, toolkit=symbolic)
res = ana.solve(s, complexfreq=True)
assert sympy.simplify(res['loopgain'] - (- A * R1 / (R1 + R2))) == 0
def test_deviceanalysis_viiv():
"""Loopgain of a resistor V-I and a I-V amplifier with a vcvs as gain element"""
sympy.var('R1 R2 CL A s')
cir = SubCircuit(toolkit=symbolic)
cir['A1'] = VCVS(gnd, 'int', 'out', gnd, g = A,toolkit=symbolic)
cir['R1'] = R('in', 'int', r=R1)
cir['R2'] = R('int', 'out', r=R2)
cir['VS'] = VS('in', gnd)
ana = FeedbackDeviceAnalysis(cir, 'A1', toolkit=symbolic)
res = ana.solve(s, complexfreq=True)
assert simplify(res['loopgain'] - (- A * R1 / (R1 + R2))) == 0
def test_deviceanalysis_sourcefollower():
"""Loopgain of a source follower"""
gm,RL,CL,s = sympy.symbols('gm RL CL s')
cir = SubCircuit(toolkit=symbolic)
cir['M1'] = VCCS('g', 's', gnd, 's', gm = gm,toolkit=symbolic)
cir['RL'] = R('s', gnd, r=RL)
cir['CL'] = C('s', gnd, c=CL)
cir['VS'] = VS('g', gnd)
ana = FeedbackDeviceAnalysis(cir, 'M1', toolkit=symbolic)
res = ana.solve(s, complexfreq=True)
assert_equal(simplify(res['loopgain']), simplify(- gm / (1/RL + s*CL)))
# -*- coding: latin-1 -*-
# Copyright (c) 2008 Pycircuit Development Team
# See LICENSE for details.
from pycircuit.circuit import SubCircuit, VCCS, G, C, IS, VS, Parameter, gnd, \
R, symbolic, TwoPortAnalysis, AC, Noise
from pycircuit.circuit.mos import MOS
from sympy import Symbol, simplify, ratsimp, sympify, factor, limit
from numpy import array, zeros
from copy import copy
from pycircuit.circuit.symbolicapprox import *
## Create regulated cascode circuit
c = SubCircuit()
nin, nout, n1 = c.add_nodes('in', 'out', 'n1')
gm1, gm2, gds1, gds2, Cgs1, Cgs2 = [
Symbol(symname, real=True)
for symname in 'gm1,gm2,gds1,gds2,Cgs1,Cgs2'.split(',')
]
c['M2'] = MOS(nin, n1, gnd, gnd, gm=gm2, gds=gds2, Cgs=0 * Cgs1)
c['M1'] = MOS(n1, nout, nin, nin, gm=gm1, gds=gds1, Cgs=0 * Cgs2)
#c['r'] = R(nin, gnd, r = Symbol('Rs', real=True))
## Perform twoport analysis with noise
twoportana = TwoPortAnalysis(c,
nin,
