DocumentCode :
1520873
Title :
Stochastic Flash Analog-to-Digital Conversion
Author :
Weaver, Skyler ; Hershberg, Benjamin ; Kurahashi, Peter ; Knierim, Daniel ; Moon, Un-Ku
Author_Institution :
Oregon State Univ., Corvallis, OR, USA
Volume :
57
Issue :
11
fYear :
2010
Firstpage :
2825
Lastpage :
2833
Abstract :
A stochastic flash analog-to-digital converter (ADC) is presented. A standard flash uses a resistor string to set individual comparator trip points. A stochastic flash ADC uses random comparator offset to set the trip points. Since the comparators are no longer sized for small offset, they can be shrunk down into digital cells. Using comparators that are implemented as digital cells produces a large variation of comparator offset. Typically, this is considered a disadvantage, but in our case, this large standard deviation of offset is used to set the input signal range. By designing an ADC that is made up entirely of digital cells, it is a natural candidate for a synthesizable ADC. Comparator trip points follow the nonlinear transfer function described by a Gaussian cumulative distribution function, and a technique is presented that reduces this nonlinearity by changing the overall transfer function of the stochastic flash ADC. A test chip is fabricated in 0.18- CMOS to demonstrate the concept.
Keywords :
Gaussian distribution; analogue-digital conversion; comparators (circuits); Gaussian cumulative distribution function; comparator offset; comparator trip points; digital cell; nonlinear transfer function; resistor string; stochastic flash analog-to-digital conversion; Analog-digital conversion; Calibration; Costs; Distribution functions; Moon; Resistors; Signal synthesis; Stochastic processes; Transfer functions; Voltage; Analog–digital conversion; comparators; statistical analysis; stochastic systems;
fLanguage :
English
Journal_Title :
Circuits and Systems I: Regular Papers, IEEE Transactions on
Publisher :
ieee
ISSN :
1549-8328
Type :
jour
DOI :
10.1109/TCSI.2010.2050225
Filename :
5491110
Link To Document :
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