spectrumMeas

Calculates Signal-to-Noise-and-Distortion Ratio (SINAD), Spurious Free Dynamic Range (SFDR), Effective Number of Bits (ENOB), and Signal-to-Noise Ratio (without distortion) by using discrete Fourier transform of the clipped portion of any given input signal.

The spectrum measure is used for characterizing A-to-D converters and is typically supported for transient simulation data.

The spectrum function is available only in the SKILL mode.
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     Signal is signal to be measured.
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     Start Time is the time to start clipping the signal in time domain.
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     End time is the time to end clipping in time domain.
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     Number of Samples is the number of sampled points used for the FFT.
Valid values: Any integer power of two greater than zero. For a value that is not a power of two, the function rounds it up to the next closest power of two.
Default value: Number of data points in the Signal.
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     Number of Noise bins is the number of noise bins where the size of one bin is the reciprocal of the data window width. For example, 1 ms of transient data creates a bin size of 1 kHz.
Valid values: Any integer power of two greater than or equal to zero.
Default value: 0, implying that no signal is spilling into the bins. A frequency band of bin-size times the number of bins is calculated and adjusted as a function of the selected window. Frequency components in each band to the left and right of the fundamental or the harmonics are set to zero and do not contribute to any output result.
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     Start Frequency is the lower limit of frequency range for the spectrum measures. Default value: First frequency point of the FFT.
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     End Frequency is upper limit of frequency range for the spectrum measures.
Default value: Last frequency point of the FFT.
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     Window Type is the windowing function applied to o_waveform.
Valid values: Blackman, Cosine2, Cosine4, ExtCosBell, HalfCycleSine, HalfCycleSine3, HalfCycleSine6, Hanning, Hamming, Kaiser, Parzen, Rectangular, and Triangular.
Default value: Rectangular.
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     ADC Span is the full-scale span ignoring any DC offsets. This is used in ENOB calculation.
Valid values: Any floating point number.
Default value: If ADC Span is not specified or is nil, it is assumed to be 0 and is taken to be the peak-to-peak value of the fundamental.
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     Measure Type is Result specifier.
Valid values: sinad, sfdr(db), enob, and snhr.
Default value: sinad