Signal preconditioning for analog-to-digital conversion with timestamps

A method of converting an analog signal into a digital representation comprising:

• preconditioning the analog signal, such that a preconditioned signal is generated;
• generating a quantity N of reference signals, where N is an integer equal to or greater than 1, a reference signal of the quantity being one or both of a time-varying reference signal and a non time-varying reference signal;
• comparing an amplitude of the preconditioned signal to an amplitude of the reference signal to determine whether the analog signal amplitude is greater than, less than or equal to the reference signal amplitude;
• and
• producing a timestamp when the preconditioned signal amplitude equals the amplitude of the reference signal, wherein the timestamp is a record of an amplitude equality event, and wherein the digital representation is a set of timestamps.

A method of converting an analog signal from a device under test into a digital signal representation comprising:

• preconditioning the analog signal from the device under test, wherein preconditioning comprises one or more of integrating, differentiating, and filtering the analog signal to generate a preconditioned signal;
• generating a reference signal;
• comparing an amplitude of the preconditioned signal to an amplitude of the reference signal to determine whether the preconditioned signal amplitude is greater than, less than or equal the reference signal amplitude;
• producing a first logic level in a digital signal corresponding to the reference signal while the preconditioned signal amplitude is greater than the reference signal amplitude and a second logic level in the digital signal while the preconditioned signal amplitude is less than the reference signal amplitude;
• and
• repeating comparing and producing for a period of time to obtain the digital signal representation of the preconditioned signal for the device under test,
• wherein the digital signal representation comprises representations for a plurality of amplitude equality events.

An apparatus that converts an analog signal to a quantity N of digital signals, where N is an integer equal to or greater than 1, the apparatus comprising:

• a reference signal source having a quantity N of source outputs, the reference signal source generating separate reference signals of a quantity N of reference signals at the source outputs;
• a quantity N of comparators connected to the reference signal source, the comparators receiving respective separate reference signals;
• and
• means for preconditioning the analog signal connected between an apparatus input and the comparators, the preconditioning means generating a preconditioned signal of the analog signal, the comparators further receiving the preconditioned signal, the comparators producing respective separate digital signals of the quantity N digital signals;
• wherein the comparators are connected to separate apparatus outputs of a quantity N of apparatus outputs, and wherein a digital signal of the quantity N digital signals comprises a set of timestamps, a timestamp being a record of an amplitude equality event between an amplitude of the preconditioned signal and an amplitude of a reference signal.

An apparatus for converting an analog signal having an amplitude to a digital signal comprising:

• a preconditioner that receives the analog signal from an apparatus input and produces a preconditioned signal;
• a reference signal source that generates separate reference signals of a quantity N of reference signals , where N is an integer equal to or greater than 1,;
• and
• a comparator connected to receive the preconditioned signal from the preconditioner, the comparator being further connected to receive the generated reference signals from the reference signal source, the comparator producing a digital signal at a comparator output, the comparator output being connected to an apparatus output,
• wherein the produced digital signal comprises a set of timestamps, a timestamp being a record of an amplitude equality event between an amplitude of the preconditioned signal and an amplitude of a reference signal.