下载
SamplingSARADC
Oversampling
Delta-SigmaADC
Single
sampleper
conversion
Multiplesamples,
averaged
SignalNoise
1 2
3 4
Data
Out
PipelineADC
1 2
3 4
Data
Out
1 2
3 4
Data
Out
1
2
1
2
Application Report
SBAA147B–August 2006–Revised October 2011
A Glossary of Analog-to-Digital Specifications and
Performance Characteristics
Bonnie Baker ................................................................................................ Data Acquisition Products
ABSTRACT
This glossary is a collection of the definitions of Texas Instruments' Delta-Sigma (ΔΣ), successive
approximation register (SAR), and pipeline analog-to-digital (A/D) Converter specifications and
performance characteristics. Although there is a considerable amount of detail in this document, the
product data sheet for a particular product specification is the best and final reference. To download or
view a specific data converter product data sheet, see the Texas Instruments web site at www.ti.com/.
Glossary of Terms
Acquisition Time:
Refer to Figure 1 when comparing SAR, Pipeline, and Delta-Sigma converter acquisition time.
Figure 1. SAR vs Pipeline vs ΔΣ A/D Converters Sampling Algorithms Comparison
• Acquisition time, Delta-Sigma A/D Converters–
The Delta-Sigma (ΔΣ) converter averages multiple samples for each conversion result. The averaging
performed by the converter usually occurs in the form of a Finite Impulse Response (FIR) or Infinite
Impulse Response (IIR) digital filter. Consequently, the acquisition time is longer than it is with a SAR
or pipeline converter, which only samples the signal once for each conversion. Figure 1 illustrates one
of the differences between the sampling mechanism of a SAR, a Pipeline and a ΔΣ converter. If the
I
2
C is a trademark of Koninklijke Philips Electronics N.V.
SPI is a trademark of Motorola, Inc.
All other trademarks are the property of their respective owners.
1
SBAA147B–August 2006–Revised October 2011 A Glossary of Analog-to-Digital Specifications and Performance Characteristics
Submit Documentation Feedback
Copyright © 2006–2011, Texas Instruments Incorporated
