Evaluation system and method for AD converter

A system for evaluating an analog-to-digital converter comprising:

• a signal generator for generating an analog signal that is wave-shaped;
• a timing controller for generating a clock which is used in feeding the analog signal to an analog-to-digital converter under test;
• Hilbert pair resampling means for deriving from an output digital signal from the analog-to-digital converter a digital signal corresponding to a cosine wave and a digital signal corresponding to a sine wave both having the period of the analog signal and which are related to each other as a Hilbert transform pair;
• instantaneous amplitude calculation means for determining an instantaneous amplitude representing both digital signals derived by the Hilbert pair resampling means;
• interleaver means receiving the instantaneous amplitude and an amplitude of the analog signal as inputs and forming an interleaved signal in which the instantaneous amplitude and the amplitude of the analog signal are interleaved;
• first transforming means receiving the interleaved signal as input and applying a wavelet transform to the interleaved signal to supply a first transformed signal as output;
• second transforming means receiving the first transformed signal as input and applying a wavelet transform to the first transformed signal to supply a second transformed signal as output;
• and first peak detecting means receiving the second transformed signal as input and determining a maximum value thereof to estimate the differential non-linearity of the analog-to-digital converter.

A method of evaluating an analog-to-digital converter under test by supplying a wave-shaped analog signal thereto, comprising the steps of:

• supplying a wave-shaped analog signal to the analog-to-digital converter under test at a timing determined by a clock;
• a Hilbert pair resampling which derives from an output digital signal from the analog-to-digital converter a digital signal corresponding to a cosine wave and a digital wave corresponding to a sine wave each having the period cf analog signal and which are related to each other as a Hilbert transform pair;
• calculating an instantaneous amplitude of the digital signal from the digital signal corresponding to the cosine wave and the digital signal corresponding to the sine wave;
• deriving a moving difference signal of the instantaneous amplitudes;
• and determining a maximum value among the moving difference signals to estimate the differential non-linearity of the analog-to-digital converter.

A method of evaluating an analog-to-digital converter under test by supplying a waved-shaped analog signal thereto, comprising the steps of:

• supplying the analog signal to the analog-to-digital converter under test at a timing determined by a clock;
• a Hilbert pair resampling which derives from the output digital signal from the analog-to-digital converter a digital signal corresponding to a cosine wave and a digital signal corresponding to a sine wave, both having the period of the analog signal and which are related to each other as a Hilbert transform pair;
• calculating an instantaneous amplitude of the digital signal from the digital signal corresponding to the cosine wave and the digital signal corresponding to the sine wave;
• forming a interleaved signal in which the instantaneous amplitude and the amplitude of the analog signal are interleaved;
• a first transform step for applying a wavelet transform to the interleaved signal;
• a second transform step applying a wavelet transform to the wavelet transformed signal;
• and determining a maximum value of the transform output from the second transform step to estimate the differential non-linearity of the analog-to-digital converter.