SYSTEMS, DEVICES, AND METHODS FOR CONTINUOUS-TIME DIGITAL SIGNAL PROCESSING AND SIGNAL REPRESENTATION

• US 20130057423A1
• Filed: 10/12/2010
• Published: 03/07/2013
• Est. Priority Date: 10/12/2009
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation), Trustees Of Columbia University In The City Of New York (Columbia University)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation), Trustees Of Columbia University In The City Of New York (Columbia University)
• Inventors: Tsividis, Yannis, Morche, Dominique, Lachartre, David, Kurchuk, Mariya, Weltin-Wu, Colin
• Granted Patent: US 8,749,421 B2
• Time in Patent Office: Days
• US Class Current: 341/155
• CPC Class Codes: H03M 1/0631 Smoothing
• CPC Class Codes: H03M 1/0697 in time, e.g. using additional comparison cycles
• CPC Class Codes: H03M 1/0854 of quantisation noise
• CPC Class Codes: H03M 1/12 Analogue/digital converters H03M1/001 – H03M1/10 take precedence
• CPC Class Codes: H03M 1/1215 using time-division multiplexing
• CPC Class Codes: H03M 1/125 Asynchronous, i.e. free-running operation within each conversion cycle
• CPC Class Codes: H03M 1/127 at intervals varying with the rate of change of the input signal
• CPC Class Codes: H03M 1/361 having a separate comparator and reference value for each quantisation level, i.e. full flash converter type
• CPC Class Codes: H03M 1/74 Simultaneous conversion
• CPC Class Codes: H04R 25/00 Deaf-aid sets , i.e. electro-acoustic or electro-mechanical hearing aids; Electric tinnitus maskers providing an auditory perception electrical stimulation of auditory nerves to promote the auditory function A61N1/36038; optical stimulation of auditory nerves to promote the auditory function A61N5/0622

Abstract

Systems, devices, and methods for continuous-time digital signal processing and signal representation are disclosed. This includes a continuous-time analog-to-digital converter that is configured to receive an analog signal and convert it to a continuous-time digital signal without using a clock or any type of sampling. This A/D conversion can include a per-level representation and a per-edge representation of the analog signal to produce a digital signal. The digital signal can then be processed in a continuous-time signal processor. The continuous time signal representation and processing can have benefits such a providing filters in high frequency applications where sampling is not practical.

Claims

1. A system for continuous-time signal processing comprising:

a continuous-time analog-to-digital converter that is configured to receive an analog input signal, determine time points at which the analog input signal crosses one of a plurality of quantization levels, and produce multiple digital signals representing the analog input signal, wherein the multiple digital signals include a first edge signal and a second edge signal associated with one of the plurality of quantization levels, the first edge signal associated with an upward crossing of the quantization level and the second edge signal associated with a downward crossing of the quantization level; and

a continuous-time digital signal processor coupled to the continuous-time analog-to-digital converter and configured to process the produce first edge signal and the second edge signal to provide a processed digital signal.

2. The system of claim 1, wherein the multiple digital signals include a level signal associated to one of the plurality of quantization levels, wherein a value of the level signal is configured to switch from a first value to a second value in accordance with the upward crossing of the quantization level.

3. The system of claim 1, wherein the multiple signals include at least one binary signal representing at least one quantization level.

4. The system of claim 1, further comprising an analog summation circuit configured to convert the processed digital signals into analog signals and sum the analog signals to produce an analog output signal.

5. The system of claim 4, wherein the analog summation circuit comprises a cascaded arrangement of delays and charge pumps to convert the processed digital signals into analog signals.

6. The system of claim 1, wherein the continuous-time digital signal processor comprises a finite impulse response filter to process the first edge signal and the second edge signal.

7. The system of claim 1, further comprising a low noise amplifier coupled to an input of the continuous-time analog-to-digital converter.

8. The system of claim 1, wherein the quantization levels are uniformly spaced.

9. A method for continuous-time signal processing comprising:

receiving an analog input signal at a continuous-time analog-to-digital converter;

determining time points at which the analog input signal crosses each quantization level of a plurality of defined quantization levels;

producing a digital signal for each quantization level, the digital signal having a value that changes based on the analog input signal crossing the quantization level;

producing, for the digital signal of at least one of the quantization levels, a plurality of transition signals based on transitions of the value of the digital signal; and

processing the plurality of transition signals of each quantization level in a continuous-time digital signal processor to produce processed digital signals.

10. The method of claim 9, wherein the step of producing a plurality of transition signals for each digital signal comprises producing at least a first edge signal based on rising edges of the digital signal and at least a second edge signal based on falling edges of the digital signal.

11. The method of claim 10, further comprising producing a third edge signal and a fourth edge signal, wherein the first and third edges signals correspond to alternating rising edges of the digital signal and the second and fourth edge signals correspond to alternating falling edges of the digital signal.

12. The method of claim 9, wherein transition signals are only produced for the digital signals of a predetermined number of higher-amplitude quantization levels.

13. The method of claim 9, wherein transition signals are produced for the digital signal of all quantization levels.

14. The method of claim 9, further comprising:

converting the processed digital signals into analog signals; and

summing the analog signals to produce an analog output signal.

15. The method of claim 14, wherein the processed digital signals are converted into analog signals using a cascaded arrangement of delays and charge pumps.

16. The method of claim 9, wherein the processing of the digital signal or transition signals of each quantization level in the continuous-time digital signal processor comprises finite impulse response filtering.

17. (canceled)

18. A continuous-time signal processor, configured to be deployed in a biomedical application, comprising:

a continuous-time analog-to-digital converter that is configured to receive an analog input signal, determine time points at which the analog input signal crosses each quantization level of a plurality of defined quantization levels, produce a digital signal for each quantization level, the digital signal having a value that changes at the determined time points of the quantization level, and produce, for the digital signal of at least one of the quantization levels, a plurality of transition signals based on transitions of the value of the digital signal; and

a continuous-time digital signal processor coupled to the continuous-time analog-to-digital converter and configured to process the plurality of transition signals of each quantization level to produce processed digital signals.

19. The continuous-time signal processor of claim 18, wherein the plurality of transition signals comprises at least a first edge signal based on rising edges of the digital signal and at least a second edge signal based on falling edges of the digital signal.

20. The continuous-time signal processor of claim 18, further comprising a low noise amplifier configured to receive and amplify an analog signal to provide the analog input signal to the continuous-time analog-to-digital converter.

21. The continuous-time signal processor of claim 18, wherein the biomedical application comprises hearing aids.