Method and apparatus for digital sampling of electrical waveforms

In an uncompensated channel of a digital sampling oscilloscope said uncompensated channel having uncompensated frequency response spectral characteristics that differ from desired frequency response spectral characteristics of a compensated channel, a method for compensating the, comprising the steps of:

• a) receiving an electrical signal;
• b) sampling said electrical signal at selected times;
• c) digitizing said samples;
• c) acquiring a predetermined number of the digitized said samples and forming a corresponding respective acquisition of said samples;
• d) storing each of said respective acquisitions in an acquisition memory without combining said respective acquisitions;
• e) repeating steps a) through e) a predetermined number of times to form a plurality of said acquisitions;
• f) retrieving said plurality of acquisitions from said acquisition memory;
• g) selectably equalizing the digitized said samples by providing a plurality of selectable frequency response filter characteristics, selecting one or more of said plurality of filter characteristics to compensate the channel for the frequency response spectral characteristics of the channel so as to cause the frequency response spectral characteristics of the channel to substantially match the frequency response spectral characteristics of the desired compensated channel, and filtering the channel with said one or more filter characteristics;
• and
• h) combining said plurality of acquisitions to form an equivalent time record.

A method for sampling in a digital sampling oscilloscope, comprising the steps of:

• a) receiving an electrical signal at a plurality of A/D converters;
• b) interleaving operation of said A/D converters to sample said electrical signal at selected times to produce digitized interleaved samples;
• c) acquiring a predetermined number of said digitized interleaved samples in response to a trigger and forming a corresponding respective acquisition of said samples;
• d) storing each of said respective acquisitions in an acquisition memory without combining said respective acquisitions;
• e) repeating steps a) through e) a predetermined number of times to form a plurality of stored ones of said acquisitions;
• f) retrieving said plurality of acquisitions from said acquisition memory;
• and
• g) combining said plurality of acquisitions to form an equivalent time record.