ADC/DAC performance __"ABC soup "
ADC = A nalog to Digital Converter | DAC = D igital to Analog Converter
(A2D: Analog to Digital) (D2A: Digital to Analog)
DC = quasi-static parameters | AC = dynamic parameters
(DC : "direct - current") (AC: "alternating - current")Standards:
IEEE IM TC-10 Technical Committee on Waveform Measurement and AnalysisBasic parameters:
http://grouper.ieee.org/groups/1057
IEEE 1057 - Standard for Digitizing Waveform Recorders
This working group is currently updating Std. 1057- 1994. The goal is to update the standard to make it consistent with the analog to digital converter standard and to make it more user frien dly.
IEEE 1241 - Standard for Terminology and Test Methods for Analog-to-Digital Converters
This working group completed IEEE standard 1241 in late 2000. The group is currently working towards incorporating much of this standard into an IEC standard on dynamic testing of ADCs.
IEEE 1658 - Standard for Terminology and Test Methods for Digital-to-AnalogConverters
In preparation. This working group was officially started in the Spring of 2004 . The group is currently working towards writing a standard on the static and dynamic testing of DACs .
Methods and draft standards for the DYNamic characterization and testing of
Analogue to Digital Converters. European Project DYNAD
http://www.fe.up.pt/~hsm/dynad/index.htmlIMEKO TC-4 Working Group on
Analogue-to-Digital & Digital-to-Analogue Converter Metrology
http://lesim1.ing.unisannio.it/tc4/ADCAndDACMetrology.htm
EUPAS: EUropean Project for ADC-based devices Standardization,
IMEKO TC-4 Working Group on A/D Converters
http://elve.le.ttu.ee/mesel_www_home/R&D/ADC/EUPAS.HTM
IEC 62008 Ed. 1.0 b: 2005
Performance characteristics and calibration methods for digital data acquisition systems and relevant software
http://domino.iec.ch/preview/info_iec62008%7Bed1.0%7Db.pdf
S. W. Smith : " The Scientist & Engineer's Guide to DSP "
Ch. 2 - Statistics, Probability and Noise | Ch. 3 - ADC and DAC
Understanding Data Converter | Data Converter Terminology
ADC and DAC Glossary
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"[What's important to note is that] while differential non-linearity is found in all DACs as well as ADCs, it has no counterpart in the analog domain. Differential non-linearity, like jitter, is a uniquely digital form of non-linear distortion" [D. Rife]
"It is also known that of the [above-mentioned] ADC test techniques only histogram analysis can give localized information about converter's errors (e.g., non-linearity parameters like differential (DNL) and integral non-linearities (INL)). The effect of an error on a particular bit of the ADC is dissolved within the RMS error in the sine wave fitting, or into the noise power of the discrete Fourier transform ." [Mendonça et al: ADC testing using joint time-frequency analysis, Computer Standards & Inerfaces, Vol.23, May 2001, pp 129-135]
DC performance ___"transfer function (linearity); intrinsic parameters"J. Horn: "DC Specifications of ADC s and DACs": Part1 · Part2 · Part3 · Part4
- OE: offset error
- GE: gain error
- DNL: Differential Non-Linearity (DLE: Differential Linearity error)
- monotonicity (DAC ), NMC: non missing code (ADC)
- INL: Integral Non-Linearity (ILE: Integral Linearity Error)
- equivalent RMS input noise
- PSRR: Power Supply Rejection Ratio
"The Relationship between Harmonic Distortion and Integral Non-Linearity "
INLandSFDR
ADC definitions and specifications
The ABCs of ADCs : Understanding How ADC Errors Affect System Performance
The Wild West of Data Acquisition Performance Specifications
AC performance ___ "noise and distortions; transmission parameters"
- SNR: Signal-to-Noise Ratio (without harmonics)
SNHR: signal to non-harmonic ratio | SRNR: signal to random noise ratio
- THD: Total Harmonic Distortion
SDR : signal-to-distortion-ratio
SNR and THD Pictorial in Selecting an Amplifier for Data Converter
NOTE: Amplifiers and Bits: An Introduction to Selecting
Amplifiers for Data Converters, Rev.B - Dec. 2001
- SINAD: SIgnal to Noise And Distortion ratio
SNDR : signal-to-noise-and-distortion ratio
SNR / THD / SINAD Calculator , pdf | Data conversion calc2 / calc3
- SFDR: Spurious-Free Dynamic Range
UCFDR: unwanted-component-free dynamic range | SFSR: spurious-free signal range
SFDR and NPR Pictorial in Designing with Hi-Speed ADCs - ENOB: Effective Number Of Bits
NOEB: number of effective bits
EB: effective (equivalent) bits
Understanding ENOB
Overall accuracy = ENOB
- IMD: InterModulation Distortion
twotone IMD
multitone IMD
- NPR: Noise Power Ratio
- MTPR: MultiTone Power Ratio
J. Horn: "A Basic Guide to the AC Specifications of ADC s ": Part1 · Part2 · Part3 · Part4
- ERBW: Effective Resolution BandWidth
- FPBW: Full-Power BandWidth
- SSBW: Small Signal BandWidth
"The Relationship between Harmonic Distortion and Integral Non-Linearity "
INLandSFDR | SQNR vs. SFDR
T. C. Hofner: "Defining And Testing Dynamic ADC Parameters": Part1 · Part2
Defining and Testing Dynamic Parameters in High-Speed ADCs
Analog Acquisition Sub-System Testing in the Frequency Domain
Understanding data converter frequency domain specifications
Understanding high speed ADC testing and evaluation
Understanding and comparing datasheest for high-speed ADCs
A reproducibile procedure for ADC testing
ADC_Jitter | FoM
Analog Devices · Live data sheets!
ADC Analyzer™ incorporates ADIsimADC™ in conjunction with product model files.
Using ADIsimADC both streamlines and improves system design evaluation. It enables the designer to observe detailed performance data for a 'simulated' ADC design within minutes. Product model files are used in conjunction with the simulator engine to produce datasheet-like ADC performance results given a specified operating condition. Data output can be extracted for further analysis.
ADIsimADC WEB based version: http://designtools.analog.com/dtSimADCWeb/dtSimADCMain.aspx
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National offers for sale demonstration kits which includes fully loaded and tested evaluation board that is ready to help you evaluate the performance of the various A/D Converters.
Many of these converters can be evaluated with the aid of our WaveVision® software , which is supplied with the evaluation board. To evalute many of these ADCs with the WaveVision® software, it is necessary to connect the evaluation board to our Digital Interface Board.
ADC Channel Design process: Signal-Path Designer Webench
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Intersil · Test Drive our CommLink™ ADCs!
DACs/ADCs Test Drive · We Test - You Drive!
Use this form to request spectral testing on any of the listed CommLink converters . We will email you the test results! This service is provided free of charge by Intersil to assist you in the product selection process.*
Texas · Digital Data Capture and Analysis for High Speed, High Resolution ADCs
TSW1100 - This tool works with ADC hardware-evaluation boards to provide instant datacapture, processing, and graphics on a design engineer's desktop computer.
ADCPro (TM) Analog-to-Digital Converter Evaluation Software
*
ADC Test Data Evaluation Program for MATLAB
Standard framework for IEEE-STD-1241 in MATLAB
Design-to-test (D2T ) and design-for-test (D4T) of mixed-signal devices:
HABIST case studyEDN Hands-On Project: Demystifying ADCs · Remystifying ADC
"Before getting into our test results, it might be useful to define the following terms. High SNR is crucial in Doppler-radar applications, and radar designers are willing to accept relatively low SFDR figures to obtain high SNR.
- SNR is a measure of the broadband noise introduced into the signal from the ADC and the sampling process. SNR compares the magnitude of the input sine wave to the sum of all other frequencies, except those representing harmonics of the fundamental.
- Total harmonic distortion (THD) is the ratio of the fundamental to the sum of the harmonics.
- SNR and distortion (SINAD) is the ratio of the power in the fundamental frequency bin to that in all other bins, including harmonics .
- Spurious-free dynamic range (SFDR) is the difference in magnitudes of the fundamental and the highest spur.
- Static noise is the number of bits of instability in the output code with the analog input held at a constant dc level.
Conversely, high SFDR is of prime importance in communications applications. Digital wireless systems can falsely recognize spurs as channels. The way to obtain high SFDR at the expense of SNR is to restrict the full-scale input range.
Designers of data-acquisition and automatic test systems are principally interested in THD, because it's a measure of the integral linearity of the transfer function.
High SINAD is important in medical systems and automatic test equipment."
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Selecting The Optimal DAC Means Knowing How To Interpret Converter Specifications And Their Effect On System Performance
Intersil · Test Drive our CommLink™ DACs!
DAC Test Drive · We Test - You Drive!
Simply fill out a on-line form to request your customized test for Intersil's CommLink TM family of DACs.Practical Telecom DAC Testing
Selecting mixed-signal components - aliases, images, and spurs
"Several specifications can be used to measure the dynamic performance of D/A converters in the frequency domain (see Figure 4):
Spurious-free dynamic range (SFDR)—the difference in signal strength (dB) between the desired signal (could be single tone or multi-tone) and the highest spurious signal in the band being measured (Figure 4). Often, the strongest spurious response is one of the harmonics of the desired output signal. In some applications, the SFDR may be specified over a very narrow range that does not include any harmonics. For narrowband transmitters, where the DAC is processing a signal that looks similar to a single strong tone, SFDR is often the primary spec of interest.These specifications, or others derived from them, represent the primary measures of a DAC’s performance in signal-synthesis applications. Besides these, there are a number of conventional DAC specifications, many associated with video DACs or other applications, that are still prevalent on DAC data sheets. These include integral nonlinearity (INL ), differential nonlinearity ( DNL ), glitch energy (more accurately, glitch impulse), settling time , differential gain ( DG ) and differential phase (DP ). While there may be some correlation between these time-domain specifications and the true dynamic measures, the time-domain specs aren’t as good at predicting dynamic performance."
Total harmonic distortion (THD)—while SFDR indicates the strength of the highest single spur in a measured band, THD adds the energy of all the harmonic spurs (say, the first 8).
Two-tone intermodulation distortion(IMD) —if the D/A converter has nonlinearities, it will produce a mixing action between synthesized signals. For example, if a nonlinear DAC tries to synthesize signals at 1.1 and 1.2 MHz, second-order intermodulation products will be generated at 100 kHz (difference frequency) and 2.3 MHz (sum frequency). Third-order intermodulation products will be generated at 1.3 MHz (2 ´ 1.2 – 1.1) and 1.0 MHz (2 ´ 1.1 – 1.2). The application determines which intermodulation products present the greatest problems, but the third-order products are generally more troublesome, because their frequencies tend to be very close to those of the original signals.
Signal-to-noise-plus-distortion (SINAD)—THD measures just the unwanted harmonic energy. SINAD measures all the non-signal based energy in the specified portion of the spectrum, including thermal noise, quantization noise, harmonic spurs, and non-harmonically related spurious signals. CDMA (code-division, multiple-access) systems, for example, are concerned with the total noise energy in a specified bandwidth: SINAD is a more-accurate figure of merit for these applications. SINAD is probably the most difficult measurement to make, since many spectrum analyzers don’t have low-enough input noise. The most straightforward way to measure a DAC’s SINAD is with an ADC of significantly superior performance.Fundamentals of modern audio measurements
HpW-Works
Read the fine print or suffer the consequences | How to read a semiconductor data sheet
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http://www.acronymfinder.com/
...
ADC Airborne Digital Computer
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DAC Digital-to-Analog Converter
DAC Data Access Component
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DAC Data Analysis Console
DAC Data Authentication Code
DAC Days After Contract (award)
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