US 7,405,689 B2 · Predictive analog to digital converters and methods of using

Abstract

Methods and devices perform analog to digital signal conversion in shorter time and/or with less power consumption than that of a comparable analog to digital conversion that uses a conventional sequential approximation method based on a binary search. A predictive guess is supplied as a digital first signal. The digital first signal is converted (D/A) to a counterpart, analog guess signal. Fewer cycles and less power is consumed if the initial guess is within a certain range of the actual magnitude of the analog input sample signal. In one embodiment, a digital modeler is used to model a process underlying the analog input sample signal to thereby provide fairly good guesses.

Claims57

Dependent claims

A method of performing analog-to-digital conversion (A/D conversion) comprising:

(a) receiving a first analog input sample signal or a scaled version thereof;
(b) receiving a first digital start value signal and storing the same as a digital guessed value signal;
(c) converting the digital guessed value signal into an analog guessed value counterpart signal;
(d) comparing the analog guessed value counterpart signal against the received first analog input sample signal or against the scaled version thereof and generating a corresponding digital comparison signal representative of the relationship found by said analog comparison of the analog guessed value counterpart signal and the first analog input sample signal or the scaled version thereof;
(e) storing the digital comparison signal as part of a digitally-expressed comparison history signal;
(f) using the comparison history signal to generate a corresponding correction value signal in accordance with a predefined correction sequence algorithm;
(g) combining the generated, correction value signal with the digital guessed value signal to produce a next digital guessed value signal that replaces the previous digital guessed value signal;
and
(h) repeating steps (c) through (g) two or more times while using the next digital guessed value signal as the digital guessed value signal until said predefined correction sequence algorithm indicates a stop condition has been reached.

6 more elements

A device which performs analog-to-digital signal conversion (A/D conversion), the device comprising:

(a) an input receiver coupled to receive a first analog input sample signal or a scaled version thereof;
(b) a guess receiver coupled to receive a first digital start value signal and configured to store the same as a digital guessed value signal;
(c) a digital to analog converter coupled to convert the digital guessed value signal into an analog guessed value counterpart signal;
(d) an analog comparator coupled to compare the analog guessed value counterpart signal against the received first analog input sample signal or against the scaled version thereof and configured to generate a corresponding digital comparison signal representative of the relationship found by said analog comparison of the analog guessed value counterpart signal and the first analog input sample signal or the scaled version thereof;
(e) a history recorder configured to store the digital comparison signal as part of a digitally-expressed comparison history signal;
(f) a correction generator configured to use the comparison history signal to generate a corresponding correction value signal in accordance with a predefined correction sequence algorithm;
(g) a combiner configured to combine the generated, correction value signal with the digital guessed value signal and to thereby produce a next digital guessed value signal that replaces the previous digital guessed value signal;
and
(h) a sequencer configured to cause the digital to analog converter (c), the analog comparator (d), the history recorder (e), the correction generator (f), and the combiner (g) to perform their respective operations two or more times while using the next digital guessed value signal as the digital guessed value signal.

6 more elements

A device which performs analog-to-digital signal conversion (A/D conversion), the A/D conversion device comprising:

(a) a first receiver for receiving a first analog input sample signal;
(b) a second receiver for receiving a digital start value signal and storing the same as a digital guessed value signal;
(c) a digital to analog converter coupled to the second receiver for converting the digital guessed value signal into an analog guessed value counterpart signal;
(d) a difference detector coupled to the digital to analog converter and also to the first receiver for measuring a difference, if any, between the analog guessed value counterpart signal and the received first analog input sample signal;
(e) a first residue converter, coupled to the difference detector for generating a corresponding first digital residue signal representative of the measured difference;
and
(f) a signal combiner, coupled to the first residue converter and to the second receiver, for combining the generated, digital residue signal with the digital guessed value signal to produce either a final digital result signal or a next digital guessed value signal that replaces the previous digital guessed value signal.

4 more elements

Dependencies are inferred from the claim text.

Predictive analog to digital converters and methods of using

Life of this patent

Predictive analog to digital converters and methods of using

Life of this patent

Abstract

Claims57