def circuit():
circuit = Circuit()
circuit.add_resistor(value="430", node1="n1", node2="nm")
circuit.add_capacitor(name="c1", value="10u", node1="nm", node2="gnd")
circuit.add_resistor(value="43k", node1="nm", node2="nout")
circuit.add_capacitor(value="47p", node1="nm", node2="nout")
circuit.add_library_opamp(model="LT1124", node1="gnd", node2="nm", node3="nout")
return circuit
def test_input_noise_units(self):
"""Check units when projecting noise to input."""
circuit = Circuit()
circuit.add_capacitor(value="10u", node1="gnd", node2="n1")
circuit.add_resistor(value="430", node1="n1", node2="nm", name="r1")
circuit.add_resistor(value="43k", node1="nm", node2="nout")
circuit.add_capacitor(value="47p", node1="nm", node2="nout")
circuit.add_library_opamp(model="LT1124",
node1="gnd",
node2="nm",
node3="nout")
analysis = AcNoiseAnalysis(circuit=circuit)
kwargs = {
"frequencies": self.f,
"node": "n1",
"sink": "nout",
"incoherent_sum": True
}
# Check the analysis without projecting.
solution = analysis.calculate(input_type="current", **kwargs)
self.assertRaises(ValueError,
solution.get_noise,
source="R(r1)",
sink="input")
rnoise = solution.get_noise(source="R(r1)", sink="nout")
self.assertEqual(rnoise.sink_unit, "V")
# Check the analysis, projecting to input, with voltage input.
solution = analysis.calculate(input_type="voltage",
input_refer=True,
**kwargs)
self.assertRaises(ValueError,
solution.get_noise,
source="R(r1)",
sink="nout")
rnoise = solution.get_noise(source="R(r1)", sink="n1")
self.assertEqual(rnoise.sink_unit, "V")
# Check the analysis, projecting to input, with current input.
solution = analysis.calculate(input_type="current",
input_refer=True,
**kwargs)
self.assertRaises(ValueError,
solution.get_noise,
source="R(r1)",
sink="nout")
rnoise = solution.get_noise(source="R(r1)", sink="input")
self.assertEqual(rnoise.sink_unit, "A")
import numpy as np
from zero import Circuit
from zero.analysis import AcNoiseAnalysis
from zero.tools import create_response
if __name__ == "__main__":
# 1000 frequencies between 0.1 Hz to 100 kHz
frequencies = np.logspace(-1, 5, 1000)
# Create circuit object.
circuit = Circuit()
# The photodiode is a current source that connects through a photodiode circuit model (shunt
# capacitor and series resistor).
circuit.add_capacitor(value="200p", node1="gnd", node2="nD")
circuit.add_resistor(value="10", node1="nD", node2="nm")
# Transimpedance amplifier.
circuit.add_library_opamp(model="OP27",
node1="gnd",
node2="nm",
node3="nout")
circuit.add_resistor(value="1k", node1="nm", node2="nout")
# Solve circuit.
analysis = AcNoiseAnalysis(circuit=circuit)
solution = analysis.calculate(frequencies=frequencies,
input_type="current",
node="nD",
sink="nout",
Sean Leavey
"""
import numpy as np
from zero import Circuit
from zero.analysis import AcSignalAnalysis
if __name__ == "__main__":
# 1000 frequencies between 1 Hz to 1 MHz.
frequencies = np.logspace(0, 6, 1000)
# Create circuit object.
circuit = Circuit()
# Add components.
circuit.add_capacitor(value="10u", node1="gnd", node2="n1")
circuit.add_resistor(value="430", node1="n1", node2="nm")
circuit.add_resistor(value="43k", node1="nm", node2="nout")
circuit.add_capacitor(value="47p", node1="nm", node2="nout")
circuit.add_library_opamp(model="LT1124",
node1="gnd",
node2="nm",
node3="nout")
# Solve circuit.
analysis = AcSignalAnalysis(circuit=circuit)
solution = analysis.calculate(frequencies=frequencies,
input_type="current",
node="n1")
# Scale transfer functions by 2 (e.g. to account for 50Ω network analyser as discussed in