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Digital-to analog-converting method and digital-to analog converter employing common weight generating elements

Imported: 23 Feb '17 | Published: 22 Oct '02

Shigetoshi Nakao, Toshihiko Hamasaki

USPTO - Utility Patents

Abstract

A digital-to-analog converter is provided for accomplishing analog output characteristics using different digital-to-analog conversion type digital signal processing schemes. A plurality of bits of a received digital signal are divided into a plurality of bit groups. A digital signal processing unit includes a plurality of bit group digital signal processors for receiving the plurality of bit groups. The plurality of digital signal processors employ one or more digital-to-analog conversion type digital signal processing schemes for generating a plurality of digital signal processed outputs. The converter adds the plurality of digital signal processed outputs to generate a composite signal processed output, and includes a weight generating unit for controlling a plurality of shared weight generating elements in response to the composite digital signal processed output to generate an analog output signal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating the configuration of a digitalto-analog converter according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating the configuration of a digitalto-analog converter according to a second embodiment of the present invention.

FIG. 3A is a block diagram of a parallel input mode implementation of the digital-to-analog converter of FIG.

2.

FIGS. 3B and 3C are block diagrams of serial input mode implementations of the digital-to-analog converter of FIG.

2.

FIG. 4 is a block diagram of a segmented DAC used in the implementations of FIGS. 2,

3A,

3B, and

3C.

FIGS. 5A and 5B are graphs illustrating operation of the digital-to,I lanalog converter of the present invention.

FIG. 6 is a block diagram of an implementation of the digital-toanalog converter of FIG. 2 having a parallel input mode topology, a dated divider which divides a parallel digital input word into K groups, and K decoders decoding the K groups, respectively.

Claims

1. A digital-to-analog converting method for generating an analog output signal using common weight generating element circuitry having a predetermined set of weights, comprising steps of:

2. A digital-to-analog converting method according to claim 1, further comprising the step of

3. A digital-to-analog converting method according to claim 2, further comprising the steps of:

4. A digital-to-analog converting method according to claim 2, wherein the step of generating a plurality of weight generation control digital signals comprises using different digital-to-analog conversion type digital signal processing schemes in generating the weight generation control digital signals from the plurality of digital signals.

5. A digital-to-analog converting method according to any one of claims

1-

4, wherein the step of digitally combining comprises digitally adding the plurality of weight generation control digital signals.

6. A digital-to-analog converter for providing an analog output signal using common weight generating element circuitry having a predetermined set of weights, comprising:

7. A digital-to-analog converter according to claim 6, further comprising:

8. A digital-to-analog converter according to claim 7, further comprising

9. A digital-to-analog converter according to claim 7, wherein the plurality of weight generation controlling circuitry use a plurality of different digital-to-analog conversion type digital signal processing schemes in generating the weight generation control digital signals from the plurality of digital signals.

10. A digital-to-analog converter according to any one of claims

6-

9, wherein the combining circuitry performs digital addition as the digital combining.

11. A digital-to-analog converting method for generating an analog output signal representative of a received digital input signal comprised of a plurality of bits, the method comprising the steps of:

12. A digital-to-analog converting method according to claim 11, further comprising the step of digitally processing the composite weight generation control output.

13. A digital-to-analog converter for generating an analog output signal from a received digital input signal comprised of a plurality of bits, comprising:

14. A digital-to-analog converter according to claim 13, further comprising digital signal processing circuitry for digitally processing the composite weight generation control output.

15. A digital-to-analog converter for converting a digital signal to an analog signal, comprising:

16. A digital-to-analog converter according to claim 15, wherein the group of analog-to-digital converting elements comprised of substantially equivalent weight generating elements for an M-bit output of the third digital signal group includes the number N of converting elements which is equal to or larger than M.

17. A digital-to-analog converter according to claim 16, wherein the third digital signal processing unit has a function of averaging the digital-to-analog converting elements with respect to a time axis.

18. A digital-to-analog converter according to claim 16, wherein the second digital signal processing unit for converting to K second digital signal groups includes at least one sigma-delta conversion digital signal processor.