WO1991005409A2 - Analog-to-digital converter employing a pipelined multi-stage architecture - Google Patents
Analog-to-digital converter employing a pipelined multi-stage architecture Download PDFInfo
- Publication number
- WO1991005409A2 WO1991005409A2 PCT/US1990/005472 US9005472W WO9105409A2 WO 1991005409 A2 WO1991005409 A2 WO 1991005409A2 US 9005472 W US9005472 W US 9005472W WO 9105409 A2 WO9105409 A2 WO 9105409A2
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- analog
- bit
- digital
- current
- signal
- Prior art date
Links
Classifications
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M1/00—Analogue/digital conversion; Digital/analogue conversion
- H03M1/12—Analogue/digital converters
- H03M1/124—Sampling or signal conditioning arrangements specially adapted for A/D converters
- H03M1/129—Means for adapting the input signal to the range the converter can handle, e.g. limiting, pre-scaling ; Out-of-range indication
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
- H03M1/00—Analogue/digital conversion; Digital/analogue conversion
- H03M1/12—Analogue/digital converters
- H03M1/14—Conversion in steps with each step involving the same or a different conversion means and delivering more than one bit
- H03M1/16—Conversion in steps with each step involving the same or a different conversion means and delivering more than one bit with scale factor modification, i.e. by changing the amplification between the steps
- H03M1/164—Conversion in steps with each step involving the same or a different conversion means and delivering more than one bit with scale factor modification, i.e. by changing the amplification between the steps the steps being performed sequentially in series-connected stages
- H03M1/167—Conversion in steps with each step involving the same or a different conversion means and delivering more than one bit with scale factor modification, i.e. by changing the amplification between the steps the steps being performed sequentially in series-connected stages all stages comprising simultaneous converters
- H03M1/168—Conversion in steps with each step involving the same or a different conversion means and delivering more than one bit with scale factor modification, i.e. by changing the amplification between the steps the steps being performed sequentially in series-connected stages all stages comprising simultaneous converters and delivering the same number of bits
Definitions
- This invention relates to analog-to-digital converters (ADC's), particularly ADC's fabricated using BiCMOS (i.e., bipolar and CMOS devices on the same substrate) technology.
- ADC's analog-to-digital converters
- BiCMOS i.e., bipolar and CMOS devices on the same substrate
- Multi-stage ADC's have been used for some time in situations where high resolutions are required.
- One common type of multi-stage converter is referred to as a subranging converter.
- Subranging converters provide high resolution with significantly fewer comparators and simpler logic than single-stage converters, but give up some of the inherently higher speed capabilities of single-stage parallel, or flash, converters.
- Fig. 1 shows a block diagram representation of a generic pipelined multi-stage ADC for converting an analog signal to an m-bit value or series of m-bit values.
- the analog input, V in is digitized
- Each block 12 contains a sample-and-hold amplifier (SHA) 14, a flash converter 16, and a digital-to-analog converter (DAC) 18.
- the block 12 provides as its output a RESIDUE OUT signal which is the difference between the output of SHA 14 and DAC 18, and is thus a representation of the error in the digital output of flash converter 16.
- block 22 contains a flash converter only.
- Each of the flash converters of blocks 12A, 12B, 12C and 22 provides an X-bit representation of the input signal to that particular block.
- the range of each stage is greater than one LSB (least significant bit) of the previous stage, for error correction.
- a digital delay structure is necessary to facilitate the generation of one binary word to represent the sampled analog input signal.
- This digital delay structure is provided by the various registers 24A-24F.
- Correction logic 26 combines the- outputs from registers 24D-24F, and from converter 22, to provide the digital output code, which in this case is a (4X-3) bit
- each of the first three stages 12A-12C samples and holds the output from the previous stage. Each stage then does a lowresolution analog-to-digital conversion on the sampled signal, and the code produced is converted back to an analog signal by a DAC.
- the DAC output is subtracted from the sampled input, generating the aforementioned residue signals, each of which is then passed onto the next stage.
- the residue signal is usually amplified, so that each stage operates with a similar input signal range, improving the tolerance to other sources in any given stage when compared with its predecessor stage.
- the fourth stage 22 contains an ADC only, since no residue output is generated from this block.
- the transfer functions of the ADC's are offset by one-half LSB, so that all analog values within a given range centered on a nominal analog value are represented by the same digital code. As shown in Fig. 3, this results in the first code (000) becoming one-half LSB wide, while the last code (111) becomes three-halves LSB wide. In a straight ADC, this does not represent a problem. However, in a pipelined architecture such as that of Fig. 1, where remainders are passed on from one stage to the next, recovery of codes representing inputs near full-scale values will require use of overrange correction codes.
- Fig. 1 have either used a dedicated sample-and-hold amplifier up front, followed by a quantizer section, as shown in Fig. 2, or have applied the analog input signal directly into a quantizer section.
- the timing requirements of the latter type of implementation in terms of the tolerable skew between the sampling by the SHA and the flash converter, make operation beyond eight to nine bits extremely difficult for high bandwidth input signals.
- Another object is to provide an ADC which overcomes some of the speed and settling limitations of voltage mode ADC's.
- Another object of the invention is to provide an ADC which has improved error correction when the input is close to full scale.
- Fig. 1 is a block diagram of a generic prior art multi-stage analog-to-digital converter
- Fig. 2 is a more detailed block diagram of the x-bit conversion stages of Fig. 1;
- Fig. 3 is a plot of the transfer function of an ideal analog-to-digital conversion according to the prior art;
- Fig. 4 is a block diagram of an analog-to-digital converter according to the present invention.
- Fig. 5 is a diagrammatic representation of the digital correction process performed in a converter of the type shown in Fig. 1;
- Fig. 6 is a diagrammatic representation of the digital overrange/underrange correction performed by the present invention.
- FIG. 4 a block diagram is shown for a pipelined multistage analog-to-digital
- converter 40 according to the invention.
- three stages of four-bits resolution each are illustrated.
- the outputs of the three stages may be thought of as providing digital words of n. p and q bits, respectively.
- n, p and q may have different values, it being understood that the invention is applicable to converters employing both fewer and more stages and to stages with greater or lesser, or differing resolutions.
- the first stage of the converter comprises two sample-and-hold amplifiers (SHA's;
- THA's track-and-hold amplifiers 42 and 44
- flash converter 46 or other low resolution ADC block
- DAC 48 DAC
- the final stage is simpler still, requiring only a single flash converter 72.
- the four-bit digital output of each of the flash converters is fed to an appropriate input register (82A, 84A, 86A) of a digital pipeline.
- a first track-and-hold amplifier (THA) 42 accepts an analog current or voltage input, Ain, and provides a voltage output on line 54 and a current output on line 52.
- a suitable detailed design for such a THA. is provided in U.S. Patent Application Serial No. 07/412,412, titled “CURRENT-MODE SAMPLE-AND-HOLD AMPLIFIER", filed on even date herewith in the names of David Robertson et al and commonly assigned (Attorney's Docket No. A0312/7106), the disclosure of which is hereby incorporated by reference.
- the current output of THA 42 is supplied to a second, similar THA 44
- the voltage output of THA 42 is supplied to a four-bit flash converter 46.
- the digital output of flash converter 46 is supplied to a register 82A, which is part of a pipeline arrangement. (Since there are three stages in this converter, the pipeline must be three layers deep. Accordingly, the first stage of the converter feeds a register chain 82A, 82B, 82C which is three registers in length; the second stage of the converter feeds a chain 84A, 84B, which is two registers in length; and the third stage of the converter feeds a chain 86A which is only one register in length.)
- the digital output from converter 46 is only approximate. An error, or residue signal, is thus generated, for use in refining the digital
- the output of flash converter 46 is converted back to analog form by a current mode DAC 48.
- the first stage residue output is supplied to the second stage as its input; specifically, the current I out1 is supplied to the input of a THA 62 of the same type as THA 42.
- converter 64 generates four bits of digital output from the voltage output of THA 62, representing digitally the error of the first stage's analog-to- digital conversion.
- the digital code is both
- analog output current l ana ⁇ og2 from THA 62 is
- the second stage output is supplied to flash converter 72 as the third stage input.
- the output code from that flash converter is the third stage output and is supplied directly to pipeline register 86A.
- quanitizer are combined in correction logic 90 to produce, e.g., a ten-bit representation of the analog input signal.
- Overrange and underrange indicators are set should the input signal be beyond the specified input range.
- the input to the first stage flash converter is taken from the output of the front-end THA 42.
- THA 44 goes into tracking mode.
- the flash converter 46 looks at the input of that THA. This gives the flash converter more time to settle to the correct answer, and provides a speed improvement over the prior art.
- Fig. 5 shows the operation of a prior art converter of the Fig. 1 type.
- the first stage flash converter 46 has a "transfer function" as illustrated in part A of the figure.
- a three-bit resolution is shown for the stage.
- steps 102 - 112 are LSB in span, while step 100 is 1/2 LSB in span and step 114 is 3/2 LSB in span.
- the flash converter of the second stage operates on the first stage's residue and has the same transfer function, shown at part B.
- the potential residue range is mapped onto only a portion of the full scale of the next stage.
- the residue should be less than 1 LSB and can thus be mapped to a value lying between one- fourth and three-fourths the full scale range of the next stage.
- This approach is taken because the flash converter of the previous stage may give an erroneous output code. For example, it may give the next higher or the next lower code than the "correct" conversion value. When that happens, the residue will fall outside the intended range. This condition can be detected and the information can be utilized to appropriately correct the residue from the second stage, so that the third stage will, in part C, generate the correct coder
- the steps 100 and 114 (and the corresponding first and last steps for subsequent stages) present a problem. For example, since step 114 is 3/2 LSB wide, there may be insufficient range in the next stage to accommodate the residue. An erroneous output will result.
- Fig. 6 The solution according to the present invention is shown in Fig. 6.
- another step 130 is added at the top of the range of the flash converter in each stage. This, of course, requires the use of a flash converter having an additional comparator and an additional bit of resolution.
- the top step 130 is now 1/2 LSB wide, while the next lower step (the prior art top step) 114A is reduced to being one LSB wide. An overrange condition can be corrected even for the top step.
- bit to the flash converters 46, 64 also requires the use of DAC's 48, 66, and pipeline stages 82, 84, and 86, capable of handling the additional bit (e.g., 5-bits total, instead of 4-bits).
Landscapes
- Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Analogue/Digital Conversion (AREA)
Abstract
Description
Claims
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US41241489A | 1989-09-26 | 1989-09-26 | |
US412,414 | 1989-09-26 | ||
US555,657 | 1990-07-18 | ||
US07/555,657 US5043732A (en) | 1989-09-26 | 1990-07-18 | Analog-to-digital converter employing a pipeline multi-stage architecture |
Publications (2)
Publication Number | Publication Date |
---|---|
WO1991005409A2 true WO1991005409A2 (en) | 1991-04-18 |
WO1991005409A3 WO1991005409A3 (en) | 1991-05-16 |
Family
ID=27021770
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/US1990/005472 WO1991005409A2 (en) | 1989-09-26 | 1990-09-26 | Analog-to-digital converter employing a pipelined multi-stage architecture |
Country Status (4)
Country | Link |
---|---|
US (1) | US5043732A (en) |
EP (1) | EP0541540A1 (en) |
JP (1) | JPH05502560A (en) |
WO (1) | WO1991005409A2 (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2012177059A3 (en) * | 2011-06-21 | 2013-04-11 | Samsung Electronics Co., Ltd. | Analog/digital modulation apparatus and method for controlling the same |
JP2013255229A (en) * | 2012-06-07 | 2013-12-19 | Analog Devices Inc | Background adjustment techniques for comparator |
Families Citing this family (39)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP3153271B2 (en) * | 1991-07-05 | 2001-04-03 | 株式会社日立製作所 | AD converter |
US5353027A (en) * | 1991-11-01 | 1994-10-04 | U.S. Philips Corporation | Multistep analog-to-digital converter with error correction |
US5412385A (en) * | 1993-02-22 | 1995-05-02 | Analog Devices, Inc. | Error correction testing system and method for a multistage A/D converter |
US5387914A (en) * | 1993-02-22 | 1995-02-07 | Analog Devices, Incorporated | Correction range technique for multi-range A/D converter |
KR970005828B1 (en) * | 1993-12-31 | 1997-04-21 | 김정덕 | Multiple analog/digital converter for pipeline structure |
US5389929A (en) * | 1994-02-03 | 1995-02-14 | Raytheon Company | Two-step subranging analog-to-digital converter |
WO1995030279A1 (en) * | 1994-04-29 | 1995-11-09 | Analog Devices, Inc. | Charge redistribution analog-to-digital converter with system calibration |
US5600322A (en) * | 1994-04-29 | 1997-02-04 | Analog Devices, Inc. | Low-voltage CMOS analog-to-digital converter |
US5600275A (en) * | 1994-04-29 | 1997-02-04 | Analog Devices, Inc. | Low-voltage CMOS comparator with offset cancellation |
US5668551A (en) * | 1995-01-18 | 1997-09-16 | Analog Devices, Inc. | Power-up calibration of charge redistribution analog-to-digital converter |
US5621409A (en) * | 1995-02-15 | 1997-04-15 | Analog Devices, Inc. | Analog-to-digital conversion with multiple charge balance conversions |
US5541602A (en) * | 1995-05-26 | 1996-07-30 | National Semiconductor Corporation | Multi-phased pipeland analog to digital converter |
US5682163A (en) * | 1996-03-06 | 1997-10-28 | Industrial Technology Research Institute | Semi-pipelined analog-to-digital converter |
SE516675C2 (en) * | 1996-05-07 | 2002-02-12 | Ericsson Telefon Ab L M | Method and apparatus for converting an analog current to a digital signal |
US5929796A (en) * | 1997-04-29 | 1999-07-27 | National Semiconductor Corporation | Self-calibrating reversible pipeline analog to digital and digital to analog converter |
US5929799A (en) * | 1997-07-15 | 1999-07-27 | Exar Corporation | Out-of-range detector for pipeline ADC |
US6124820A (en) * | 1997-11-20 | 2000-09-26 | National Semiconductor Corporation | Error correction architecture for pipeline analog to digital converters |
US6133864A (en) * | 1998-04-01 | 2000-10-17 | Stmicroelectronics, Inc. | Analog-to-digital converter for processing analog signals from a large array of detectors |
GB9821091D0 (en) * | 1998-09-30 | 1998-11-18 | Koninkl Philips Electronics Nv | Analogue to digital converter |
US6396429B2 (en) * | 2000-01-07 | 2002-05-28 | Analog Devices, Inc. | Front-end sampling for analog-to-digital conversion |
US6337651B1 (en) | 2000-02-17 | 2002-01-08 | Advanced Micro Devices, Inc. | Pipeline analog to digital (A/D) converter with relaxed accuracy requirement for sample and hold stage |
US6359579B1 (en) | 2000-02-17 | 2002-03-19 | Advanced Micro Devices, Inc. | Digital logic correction circuit for a pipeline analog to digital (A/D) converter |
US6323800B1 (en) | 2000-02-17 | 2001-11-27 | Advanced Micro Devices, Inc. | Pipeline analog to digital (a/d) converter with lengthened hold operation of a first stage |
FR2809247A1 (en) * | 2000-05-16 | 2001-11-23 | France Telecom | PIPELINE ANALOG-TO-DIGITAL CONVERTER WITH NOISE SHAPING |
US6489904B1 (en) * | 2001-07-27 | 2002-12-03 | Fairchild Semiconductor Corporation | Pipeline analog-to-digital converter with on-chip digital calibration |
CN100471069C (en) * | 2001-10-03 | 2009-03-18 | Nxp股份有限公司 | Analogue to digital converter |
US6864820B2 (en) * | 2002-02-28 | 2005-03-08 | Analog Devices, Inc. | Analog-to-digital conversion using an increased input range |
US6965332B2 (en) * | 2002-02-28 | 2005-11-15 | Analog Devices, Inc. | Methods and apparatus for digital offset correction using an ADC with an increased input range |
JP2003298418A (en) * | 2002-03-29 | 2003-10-17 | Fujitsu Ltd | Analog/digital converter with automatic error calibration function |
US6611222B1 (en) | 2002-06-03 | 2003-08-26 | Charles Douglas Murphy | Low-complexity high-speed analog-to-digital converters |
US6744395B1 (en) | 2002-11-27 | 2004-06-01 | International Business Machines Corporation | Power-scalable asynchronous architecture for a wave-pipelined analog to digital converter |
US6741194B1 (en) * | 2002-12-23 | 2004-05-25 | Motorola, Inc. | Methods and apparatus for detecting out-of-range signals in an analog-to-digital converter |
US6894631B1 (en) | 2004-03-31 | 2005-05-17 | Analog Devices, Inc. | Pipeline ADC digital dithering for increased digital calibration resolution |
US6965337B1 (en) * | 2004-07-26 | 2005-11-15 | Scintera Networks, Inc. | Reference generator |
US8242946B2 (en) * | 2006-11-17 | 2012-08-14 | Crest Semiconductors, Inc. | Pipelined analog-to-digital converter |
US7839318B2 (en) * | 2006-11-17 | 2010-11-23 | Siflare, Inc | Current mode pipelined analog-to-digital converter |
US7733254B2 (en) * | 2007-06-28 | 2010-06-08 | Slicex, Inc. | Sample and hold circuit for a current mode pipelined analog-to-digital converter |
US7602324B1 (en) * | 2009-01-20 | 2009-10-13 | Himax Media Solutions, Inc. | A/D converter and method for converting analog signals into digital signals |
US10256834B1 (en) * | 2017-09-29 | 2019-04-09 | Taiwan Semiconductor Manufacturing Company, Ltd. | Analog to digital converter |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3721975A (en) * | 1971-10-07 | 1973-03-20 | Singer Co | High speed analog-to-digital converter |
US3846786A (en) * | 1973-01-10 | 1974-11-05 | Westinghouse Electric Corp | High speed parallel-cascaded analog to digital connector |
Family Cites Families (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4535319A (en) * | 1983-04-08 | 1985-08-13 | Tektronix, Inc. | Method and circuit for measuring nonlinearity in dual-flash analog-to-digital converter |
US4763107A (en) * | 1985-08-23 | 1988-08-09 | Burr-Brown Corporation | Subranging analog-to-digital converter with multiplexed input amplifier isolation circuit between subtraction node and LSB encoder |
JPH0810830B2 (en) * | 1987-03-04 | 1996-01-31 | 株式会社東芝 | Analog-digital converter |
US4908621A (en) * | 1988-07-06 | 1990-03-13 | Tektronix, Inc. | Autocalibrated multistage A/D converter |
-
1990
- 1990-07-18 US US07/555,657 patent/US5043732A/en not_active Expired - Fee Related
- 1990-09-26 JP JP2513823A patent/JPH05502560A/en active Pending
- 1990-09-26 EP EP90914811A patent/EP0541540A1/en not_active Withdrawn
- 1990-09-26 WO PCT/US1990/005472 patent/WO1991005409A2/en not_active Application Discontinuation
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US3721975A (en) * | 1971-10-07 | 1973-03-20 | Singer Co | High speed analog-to-digital converter |
US3846786A (en) * | 1973-01-10 | 1974-11-05 | Westinghouse Electric Corp | High speed parallel-cascaded analog to digital connector |
Non-Patent Citations (1)
Title |
---|
1985 International Symposium on Circuits and Systems, Proceedings, 5-7 June 1985, Kyoto, Japan, vol. 1 or 3, IEEE, F. Beck et al.:"A monolithic 6 bit subconverter for high speed, high resolution sequential flash A/D conversion systems", pages 327-330 * |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2012177059A3 (en) * | 2011-06-21 | 2013-04-11 | Samsung Electronics Co., Ltd. | Analog/digital modulation apparatus and method for controlling the same |
US9083397B2 (en) | 2011-06-21 | 2015-07-14 | Samsung Electronics Co., Ltd. | Analog/digital modulation apparatus and method for controlling the same |
JP2013255229A (en) * | 2012-06-07 | 2013-12-19 | Analog Devices Inc | Background adjustment techniques for comparator |
US8773294B2 (en) | 2012-06-07 | 2014-07-08 | Analog Devices, Inc. | Background techniques for comparator calibration |
Also Published As
Publication number | Publication date |
---|---|
EP0541540A1 (en) | 1993-05-19 |
WO1991005409A3 (en) | 1991-05-16 |
US5043732A (en) | 1991-08-27 |
JPH05502560A (en) | 1993-04-28 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US5043732A (en) | Analog-to-digital converter employing a pipeline multi-stage architecture | |
US8531323B2 (en) | Pipelined analog-to-digital converter and its single redundancy bit digital correction technique | |
KR970005828B1 (en) | Multiple analog/digital converter for pipeline structure | |
US7280064B2 (en) | Pipeline ADC with minimum overhead digital error correction | |
US7233276B1 (en) | Pipelined analog to digital converter with capacitor mismatch compensation | |
KR101140349B1 (en) | The multi-stage successive approximation register analog digital converter | |
KR100332243B1 (en) | Pipeline analog-to-digital converter vessel number 2 Architecture and calibration techniques | |
US7170436B2 (en) | Current mode analog-to-digital converter using parallel, time-interleaved successive approximation subcircuits | |
US7893859B2 (en) | Converter circuit, analog/digital converter, and method for generating digital signals corresponding to analog signals | |
US9059730B2 (en) | Pipelined successive approximation analog-to-digital converter | |
US5463395A (en) | Semi-flash type A/D converter employing a correction encoder for eliminating errors in the output signals due to noise, and a corresponding method therefor | |
US7847720B2 (en) | Pipelined analog-to-digital converter | |
US6404364B1 (en) | Multistage converter employing digital dither | |
US6825783B2 (en) | Multi-stage analog-to-digital converter with pipeline structure and method for coding the same | |
US7821436B2 (en) | System and method for reducing power dissipation in an analog to digital converter | |
US6239734B1 (en) | Apparatus and a method for analog to digital conversion using plural reference signals and comparators | |
US5739781A (en) | Sub-ranging analog-to-digital converter with open-loop differential amplifiers | |
US6504500B1 (en) | A/D converter and A/D converting method | |
US5084701A (en) | Digital-to-analog converter using cyclical current source switching | |
Chen | A 16b 5MSPS two-stage pipeline ADC with self-calibrated technology | |
US20040189504A1 (en) | Semi-flash A/D converter with minimal comparator count | |
US10938399B1 (en) | Digital corrected two-step SAR ADC | |
Lin et al. | Analog-to-digital conversion | |
KR20110090669A (en) | Analog-to-digital converter with successive approximation register | |
KR950004642B1 (en) | Two step analog/digital converter |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
AK | Designated states |
Kind code of ref document: A2 Designated state(s): JP |
|
AL | Designated countries for regional patents |
Kind code of ref document: A2 Designated state(s): AT BE CH DE DK ES FR GB IT LU NL SE |
|
AK | Designated states |
Kind code of ref document: A3 Designated state(s): JP |
|
AL | Designated countries for regional patents |
Kind code of ref document: A3 Designated state(s): AT BE CH DE DK ES FR GB IT LU NL SE |
|
WWE | Wipo information: entry into national phase |
Ref document number: 1990914811 Country of ref document: EP |
|
WWP | Wipo information: published in national office |
Ref document number: 1990914811 Country of ref document: EP |
|
WWW | Wipo information: withdrawn in national office |
Ref document number: 1990914811 Country of ref document: EP |