zero.analysis.ac.noise module

class zero.analysis.ac.noise.AcNoiseAnalysis(*args, **kwargs)[source]

Bases: zero.analysis.ac.signal.AcSignalAnalysis

Small signal circuit analysis

DEFAULT_INPUT_IMPEDANCE = 50
calculate(input_type, sink, impedance=None, incoherent_sum=False, input_refer=False, **kwargs)[source]

Calculate noise from circuit elements at a particular element.

Parameters

  • input_type (str) – Input type, either “voltage” or “current”.

  • sink (str or Component or Node) – The element to calculate noise at.

  • impedance (float or Quantity, optional) – Input impedance. If None, the default is used.

  • incoherent_sum (bool or dict, optional) – Incoherent sum specification. If True, the incoherent sum of all noise in the circuit at the sink is calculated and added to the solution. Alternatively, this parameter can be specified as a dict containing labels as keys and sequences of noise sources as values. The noise sources can be either NoiseDensity objects or noise specifier strings as supported by Solution.get_noise(). The values may alternatively be the strings “all”, “allop” or “allr” to compute noise from all components, all op-amps and all resistors, respectively. Sums are plotted in shades of grey determined by the plotting configuration’s sum_greyscale_cycle_start, sum_greyscale_cycle_stop and sum_greyscale_cycle_count values.

  • input_refer (bool, optional) – Refer the noise to the input.

Other Parameters

  • frequencies (np.ndarray or sequence) – The frequency vector to calculate the response with.

  • node, node_p, node_n (Node) – The node or nodes to make the input. The node parameter sets a single, grounded input, whereas node_p and node_n together create a floating input.

  • print_equations (bool, optional) – Print the circuit equations.

  • print_matrix (bool, optional) – Print the circuit matrix.

Returns

Solution – Solution containing noise spectra at the specified sink (or projected sink).

circuit_matrix(*args, **kwargs)[source]

Calculate and return matrix used to solve for circuit noise at a given frequency.

Returns

scipy.sparse.spmatrix – The circuit matrix.

property noise_element_index

Noise element matrix index

property noise_sink
property right_hand_side_index

Right hand side excitation component index

to_signal_analysis()[source]

Return a new signal analysis using the settings defined in the current analysis.