Lydia Lee

EECS Department, University of California, Berkeley

Technical Report No. UCB/EECS-2023-227

August 14, 2023

http://www2.eecs.berkeley.edu/Pubs/TechRpts/2023/EECS-2023-227.pdf

The conversion of trigger events to their digital equivalent is a central component of any timing-based front end, with applications found in mass spectrometry, single channel analyzers, and a huge variety of 3D mapping and ranging systems. At the same time, ever- tightening size, weight, and power budgets for space launches with a skyrocketing (no pun intended) number of launches in the last decade have made application-specific integrated circuit solutions increasingly appealing. However, conventional analog methods of pulse discrimination introduce timing walk or are limited to a narrow range of pulse shapes, while early-stage digitization requires impractically high sample rates for the events in question. This work presents the analysis, design, and measurement of an integrated constant frac- tion discriminator with theoretically zero timing walk and a programmable, constant trigger fraction which does not depend on input pulse shape. The specific silicon presented here was designed for the Solar Probe Analyzer for Ions as part of its time-of-flight mass spectrometer to determine the ion composition of space plasmas. This dissertation discusses the front end requirements for a radiation hardened pulse discriminator in the context of SPAN-Ion. We then address the architectural modifications used to achieve a pulse shape-independent constant trigger fraction, as well as the analog and digital hardening techniques required to detect, correct, and/or mitigate radiation-induced effects. Finally, this work presents the first attempt at an integrated pulse-shaping front end for SPAN-Ion, concluding with sim- ulation results from a more recent chip and a discussion of future work both for SPAN-Ion and for further code base development.

Advisors: Kristofer Pister

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BibTeX citation:

@phdthesis{Lee:EECS-2023-227,
    Author= {Lee, Lydia},
    Title= {Precise Pulse Discrimination for Space-Based Timing Front Ends},
    School= {EECS Department, University of California, Berkeley},
    Year= {2023},
    Month= {Aug},
    Url= {http://www2.eecs.berkeley.edu/Pubs/TechRpts/2023/EECS-2023-227.html},
    Number= {UCB/EECS-2023-227},
    Abstract= {The conversion of trigger events to their digital equivalent is a central component of
any timing-based front end, with applications found in mass spectrometry, single channel
analyzers, and a huge variety of 3D mapping and ranging systems. At the same time, ever-
tightening size, weight, and power budgets for space launches with a skyrocketing (no pun
intended) number of launches in the last decade have made application-specific integrated
circuit solutions increasingly appealing. However, conventional analog methods of pulse
discrimination introduce timing walk or are limited to a narrow range of pulse shapes, while
early-stage digitization requires impractically high sample rates for the events in question.
This work presents the analysis, design, and measurement of an integrated constant frac-
tion discriminator with theoretically zero timing walk and a programmable, constant trigger
fraction which does not depend on input pulse shape. The specific silicon presented here was
designed for the Solar Probe Analyzer for Ions as part of its time-of-flight mass spectrometer
to determine the ion composition of space plasmas. This dissertation discusses the front
end requirements for a radiation hardened pulse discriminator in the context of SPAN-Ion.
We then address the architectural modifications used to achieve a pulse shape-independent
constant trigger fraction, as well as the analog and digital hardening techniques required to
detect, correct, and/or mitigate radiation-induced effects. Finally, this work presents the
first attempt at an integrated pulse-shaping front end for SPAN-Ion, concluding with sim-
ulation results from a more recent chip and a discussion of future work both for SPAN-Ion
and for further code base development.},
}

EndNote citation:

%0 Thesis
%A Lee, Lydia 
%T Precise Pulse Discrimination for Space-Based Timing Front Ends
%I EECS Department, University of California, Berkeley
%D 2023
%8 August 14
%@ UCB/EECS-2023-227
%U http://www2.eecs.berkeley.edu/Pubs/TechRpts/2023/EECS-2023-227.html
%F Lee:EECS-2023-227