Design of Front-End Low-Noise and
Radiation Tolerant Readout Systems
José Pedro Cardoso
Overview
Introduction
Training
Project
Milestones
Conclusions
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Design of Front-End Low-Noise and 01-10-2009
Radiation Tolerant Readout Systems
Introduction
“The “GBT Project” is part of the “Radiation Hard Optical Link Project”
which aims at developing a radiation hard bi-directional optical link for use
in the LHC upgrade programs” ( http://cern.ch/proj-gbt ).
There is the need to develop new building blocks to meet the
requirements of the Front-End electronics of the future experiments.
The goal of the project is to design one or more low-noise, radiation
tolerant circuits, either in 90 nm or 130 nm CMOS technologies.
In the framework of GBT project, a PLL with a very low phase noise will
be designed, with built-in self-test blocks.
Tape-out of this circuit is foreseen for May 2010
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Design of Front-End Low-Noise and 01-10-2009
Radiation Tolerant Readout Systems
Introduction
Training
• On-job training
• Technical Courses
Education
• Doctoral Programme
at FEUP
Project
• Low-noise Radiation
Tolerant PLL
Milestones
• Important dates for
the project
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Dissemination
• Conferences
Design of Front-End Low-Noise and 01-10-2009
Radiation Tolerant Readout Systems
Training
Training
Training
Self-training
Interaction with experts
On-Job training
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Design of Front-End Low-Noise and 01-10-2009
Radiation Tolerant Readout Systems
Training
EPLF Course – “PLLs, VCOs and Frequency Synthesizers“
Ali Hajimiri
Modelling and Design of High-Speed VCOs
Jitter and Phase Noise in PLLs
Michiel Steyaert
Low-Power Crystal Oscillators
Basic Concepts of PLL Topologies
CMOS Prescalers & Advanced Loop Filters
Integrated VCOs and Synthesizers
Ian Galton
Fractional-N PLLs
John Cowles
High Speed Synthesizers for Communications
ESSCIRC 2009 Conference
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Design of Front-End Low-Noise and 01-10-2009
Radiation Tolerant Readout Systems
Education
Training
PhD in Electrical and Computer Engineering
Design of Front-End Low-Noise and Radiation Tolerant Readout Systems
1st semester (2009/2010)
Microelectronic and Micro-electro-Mechanical Technologies
Test and Design for Testability
Digital Communication Systems
Seminars
2nd semester (2011/2012)
Advanced Microelectronic Systems Design
Instrumentation and Systems Testing
Measure Theory and Stochastic Processes
Individual Topics
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Design of Front-End Low-Noise and 01-10-2009
Radiation Tolerant Readout Systems
Project
Project
Top-level
analisys using
MatLab
IC Design Using
Cadence
Radiation/
performace
tests
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Design of Front-End Low-Noise and 01-10-2009
Radiation Tolerant Readout Systems
Project
Phase Locked Loop – PLL
Digital communication of data is affected by noise
There is the need to develop circuit that does data recovering
The PLL will act as a Jitter-filter, as well as a clock multiplier and can be
used in CDR applications.
Is a feedback system that generates an output frequency according to a
reference.
Compares the output and the input phase of two signals
Main blocks:
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Phase-Detector (PD or PFD)
Voltage Controlled Oscillator (VCO)
Low-Pass Filter (LPF)
Divider or Pre-scaler
Design of Front-End Low-Noise and 01-10-2009
Radiation Tolerant Readout Systems
Project
Phase Locked Loop – PLL
Based on QPLL characteristics
Crystal frequency = 80.1572 MHz
Locking range = 40.0786 MHz ± 8 kHz
Output Jitter < 15 ps
130 nm CMOS Technology
One frequency multiplication mode: × 2
Power voltage: 1.2 V
10 GHz VCO for High-Speed Transceiver
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Very low-phase noise characteristics
Design of Front-End Low-Noise and 01-10-2009
Radiation Tolerant Readout Systems
Project
130 nm CMOS Technology
Main focus of this period was the VCO
First approach to oscillator design was done with a
Colpitts oscillator. Later the cross-coupled pair and a
mixture of both.
First oscillator designed at schematics level @ 1 GHz
Single-ended oscillator @ 10 GHz
Differential oscillator @ 10 GHz
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Design of Front-End Low-Noise and 01-10-2009
Radiation Tolerant Readout Systems
Project
Main concerns for the VCO designer
How can the above effects be minimized ?
Phase-noise
Phase noise in the 1/f and 1/f2 regions can be upconverted to close-in regions.
Symmetry has a tremendous impact on how AM is converted into PM noise, and
can be used by designers.
A proper choice of the oscillator’s topology leads us to a better response in
terms of phase-noise.
Spurs
Phase-noise
Spurs
Variability
Proper design of charge-pump and filter
Variability
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Tank circuit designed with extra capacitors which can be enabled/disable
according to the desired center frequency.
Design of Front-End Low-Noise and 01-10-2009
Radiation Tolerant Readout Systems
Project
Main challenges and novelty
Design of the VCO
Low phase noise
Low parasitics
Insensitive to process variations
Sensitive choice of VCO’s topology
Design of several test blocks, that will perform selftest/auto-calibration of the PLL during functioning
Determination of the parameters that can be controlled
by the test mechanism
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Design of Front-End Low-Noise and 01-10-2009
Radiation Tolerant Readout Systems
Project
What to expect from the circuit ?
A low noise PLL
Embedded Built-in self-test
system
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Jitter Measuring circuit
Automatic Amplitude Control/
Automatic Gain Control
Automatic Frequency Control
Memory to save the settings of the
PLL
Design of Front-End Low-Noise and 01-10-2009
Radiation Tolerant Readout Systems
Milestones
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Milestones
Design of Front-End Low-Noise and 01-10-2009
Radiation Tolerant Readout Systems
Dissemination
Conferences
Targeted conferences:
2010
PRIME 2010 – July 2010
TWEPP 2010 – September 2010
DCIS 2010 – November 2010
2011
IM3STW 2011– June 2011
DATE 2011– March 2011
ITC 2011– October 2011
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Design of Front-End Low-Noise and 01-10-2009
Radiation Tolerant Readout Systems
Conclusions
A top-level modelling is being used to analyse and specify
the system, prior to design
There are two circuits to be developed:
Crystal PLL
LC VCO for a 10 GHz PLL
The final versions will include self-test building blocks
Tape-out of the first circuit should be done during May
2010
By September 2010 at least one paper should have been
published in one of the conferences
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Design of Front-End Low-Noise and 01-10-2009
Radiation Tolerant Readout Systems
Thank you for your attention.
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Design of Front-End Low-Noise and 01-10-2009
Radiation Tolerant Readout Systems