Pipelined analog to digital converter that is configurable based on mode and strength of received signal

• US 7,205,923 B1
• Filed: 12/07/2004
• Issued: 04/17/2007
• Est. Priority Date: 12/07/2004
• Status: Active Grant

• Current Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Original Assignee: National Semiconductor Corporation (Texas Instruments, Inc.)
• Inventors: Bahai, Ahmad
• Primary Examiner(s): Jeanglaude; Jean Bruner
• Application Number:
  US11/007,057
• Time in Patent Office: 861 Days
• Field of Search: 341/161, 341/139, 341/155, 341/156, 702/96, 702/106, 375/232, 375/343, 375/348, 370/350, 710/100, 710/110, 711/100, 711/170, 712/24
• US Class Current: 341/161
• CPC Class Codes: H03M 1/007 among different resolutions
• CPC Class Codes: H03M 1/145 the steps being performed sequentially in series-connected stages H03M1/141, H03M1/143, H03M1/16 take precedence

Abstract

A pipelined analog to digital converter (ADC) that is arranged to dynamically adapt its resolution and sampling frequency based on at least a determined mode of communication and the strength of a received wireless signal. Since standby mode data is typically communicated with a relatively low number of bits (low resolution), the ADC provides for disabling at least a portion of its pipelined stages that provide the higher resolution bits if the standby communication mode is detected. By lowering the ADC'"'"'s resolution for standby mode communication, it can conserve a considerable amount of power associated with the operation of the higher resolution bits. Similarly, relatively high resolution communication such as receiving and transmitting data and/or voice is process by the ADC by enabling sufficient pipelined stages to provide a higher number of bits.

Claims

1. A pipelined Analog To Digital Converter (ADC), comprising:

an input stage for sampling and holding an analog signal; and

a plurality of pipelined stages that are hierarchically arranged to resolve the analog signal into at least one of a plurality of bits in the digital representation of the analog signal, wherein a resolution for processing the digital representation by at least one of the plurality of stages is enabled by information that is based on the digital representation, and wherein the information indicates at least a strength that is associated with the analog signal, and wherein the resolution is controlled based on at least the strength.

2. The ADC of claim 1, wherein the information further includes a mode, and wherein the mode indicates one of a standby mode and a communication mode, wherein the standby mode is associated with a resolution for processing the analog signal that is relatively less than another resolution for processing the analog signal that is associated with the communication mode.

3. The ADC of claim 1, wherein if the strength of the analog signal is determined to be relatively weak, a frequency of the ADC is increased for processing the analog signal, and wherein if the strength of the analog signal is determined to be relatively strong, the frequency of the ADC is decreased for processing the analog signal.

7. The ADC of claim 1, wherein each of the plurality of stages includes at least one Flash ADC component.

9. The ADC of claim 1, wherein at least one of the plurality of stages includes a sample and hold component.

4. A pipelined Analog To Digital Converter (ADC), comprising:

an input stage for sampling and holding an analog signal; and

a plurality of pipelined stages that are hierarchically arranged to resolve the analog signal into at least one of a plurality of bits in the digital representation of the analog signal, wherein a resolution for processing the digital representation by at least one of the plurality of stages is enabled by information that is based on the digital representation, and wherein the information indicates at least one of a mode or a strength that is associated with the analog signal, wherein the information is arranged in at least one frame, and wherein the resolution is controlled based on at least one of the mode or the strength.

5. The ADC of claim 4, wherein the frame is formatted in accordance with a Media Access Control (MAC) format at Layer 2 of the OSI model.

6. A pipelined Analog To Digital Converter (ADC), comprising:

an input stage for sampling and holding an analog signal; and

a plurality of pipelined stages that are hierarchically arranged to resolve the analog signal into at least one of a plurality of bits in the digital representation of the analog signal, wherein a resolution for processing the digital representation by at least one of the plurality of stages is enabled by information that is based on the digital representation, and wherein the information indicates at least one of a mode or a strength that is associated with the analog signal, wherein at least one of the mode and the strength of the analog signal are employed to disable at least one of the plurality of stages and change a value of the frequency for processing the analog signal.

8. A pipelined Analog To Digital Converter (ADC), comprising:

an input stage for sampling and holding an analog signal; and

a plurality of pipelined stages that are hierarchically arranged to resolve the analog signal into at least one of a plurality of bits in the digital representation of the analog signal, wherein a resolution for processing the digital representation by at least one of the plurality of stages is enabled by information that is based on the digital representation, and wherein the information indicates at least one of a mode or a strength that is associated with the analog signal, wherein an output from each of the enabled stages is digitally correlated.

10. A pipelined Analog To Digital Converter (ADC), comprising:

an input stage for sampling and holding an analog signal; and

a plurality of pipelined stages that are hierarchically arranged to resolve the analog signal into at least one of a plurality of bits in the digital representation of the analog signal, wherein a resolution for processing the digital representation by at least one of the plurality of stages is enabled by information that is based on the digital representation, and wherein the information indicates at least one of a mode or a strength that is associated with the analog signal, wherein the other indication is employed to enable at least one of the plurality of stages and change a frequency for processing the analog signal.

11. The ADC of claim 10, wherein the other indication is employable to disable at least one of the plurality of stages.

12. A method for converting an analog signal into a digital representation of the analog signal, comprising:

sampling the analog signal;

hierarchically resolving the analog signal into a plurality of bits associated with the digital representation of the analog signal, wherein processing the analog signal with at least one of a plurality of stages is enabled by information determined from the digital representation, and wherein the information indicates at least a strength that is associated with the analog signals and wherein the processing is controlled based on at least the strength; and

enabling an output of the digital representation of the analog signal.

13. The method of claim 12, wherein the information further includes a mode, and wherein the information regarding the mode indicates at least a size of a resolution for processing the analog signal.

14. The method of claim 12, wherein the information regarding the strength of the analog signal indicates at least a sampling frequency for processing the analog signal.

15. A method for converting an analog signal into a digital representation of the analog signal, comprising:

sampling the analog signal;

hierarchically resolving the analog signal into a plurality of bits associated with the digital representation of the analog signal, wherein processing the analog signal with at least one of a plurality of stages is enabled by information determined from the digital representation, and wherein the information indicates at least one of a mode or a strength that is associated with the analog signal, and wherein the processing is controlled based on at least one of the mode or the strength; and

enabling an output of the digital representation of the analog signal, wherein the information is arranged in at least one frame.

16. The method of claim 15, wherein the frame is formatted in accordance with a Media Access Control (MAC) format at Layer 2 of the OSI model.

17. A method for converting an analog signal into a digital representation of the analog signal, comprising:

sampling the analog signal;

hierarchically resolving the analog signal into a plurality of bits associated with the digital representation of the analog signal, wherein processing the analog signal with at least one of a plurality of stages is enabled by information determined from the digital representation, and wherein the information indicates at least one of a mode or a strength that is associated with the analog signal; and

enabling an output of the digital representation of the analog signal, wherein a wireless protocol indicated by the determined information is employed to disable at least one of the plurality of stages.

18. A pipelined Analog To Digital Converter (ADC), comprising:

an input stage for sampling and holding an analog signal; and

a plurality of pipelined stages that hierarchically resolve the analog signal into at least one of a plurality of bits associated with the digital representation of the analog signal, wherein a resolution and a frequency for processing the analog signal corresponds to the operation of a plurality of stages that are enabled based on information determined from the analog signal, and wherein the information indicates at least one of a mode and a strength of the analog signal.

19. The ADC of claim 18, wherein the information includes another indication for at least one of a mode of operation and a strength of the analog signal, wherein the other indication is employed to enable at least one of the resolution and the frequency for processing the analog signal.