Design of Front-End Low-Noise and Radiation Tolerant Readout Systems José Pedro Cardoso

Overview Design of Front-End Low-Noise and Radiation Tolerant Readout Systems 2  Introduction  Training  Project  Milestones  Conclusions

Introduction Design of Front-End Low-Noise and Radiation Tolerant Readout Systems 3  “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” ( ).  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

Introduction Design of Front-End Low-Noise and Radiation Tolerant Readout Systems 4 Training On-job training Technical Courses Education Doctoral Programme at FEUP Project Low-noise Radiation Tolerant PLL Dissemination Conferences Milestones Important dates for the project

Training Design of Front-End Low-Noise and Radiation Tolerant Readout Systems 5 Training Self-training On-Job training Interaction with experts Training

Design of Front-End Low-Noise and Radiation Tolerant Readout Systems 6  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

Training Design of Front-End Low-Noise and Radiation Tolerant Readout Systems 7  PhD in Electrical and Computer Engineering Design of Front-End Low-Noise and Radiation Tolerant Readout Systems 1 st semester (2009/2010)  Microelectronic and Micro-electro-Mechanical Technologies  Test and Design for Testability  Digital Communication Systems  Seminars 2 nd semester (2011/2012)  Advanced Microelectronic Systems Design  Instrumentation and Systems Testing  Measure Theory and Stochastic Processes  Individual Topics Education

Project Design of Front-End Low-Noise and Radiation Tolerant Readout Systems 8 Top-level analisys using MatLab IC Design Using Cadence Radiation/ performace tests Project

Design of Front-End Low-Noise and Radiation Tolerant Readout Systems 9 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: Phase-Detector (PD or PFD) Voltage Controlled Oscillator (VCO) Low-Pass Filter (LPF) Divider or Pre-scaler

Project Design of Front-End Low-Noise and Radiation Tolerant Readout Systems 10  Phase Locked Loop – PLL  Based on QPLL characteristics  Crystal frequency = MHz  Locking range = 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  Very low-phase noise characteristics

Project Design of Front-End Low-Noise and Radiation Tolerant Readout Systems 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 1 GHz  Single-ended 10 GHz  Differential 10 GHz

Project  Main concerns for the VCO designer  Phase-noise  Spurs  Variability  How can the above effects be minimized ?  Phase-noise  Phase noise in the 1/f and 1/f 2 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  Proper design of charge-pump and filter  Variability  Tank circuit designed with extra capacitors which can be enabled/disable according to the desired center frequency Design of Front-End Low-Noise and Radiation Tolerant Readout Systems 12

Project Design of Front-End Low-Noise and Radiation Tolerant Readout Systems 13 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 self- test/auto-calibration of the PLL during functioning  Determination of the parameters that can be controlled by the test mechanism

Project Design of Front-End Low-Noise and Radiation Tolerant Readout Systems 14 What to expect from the circuit ?  A low noise PLL  Embedded Built-in self-test system  Jitter Measuring circuit  Automatic Amplitude Control/ Automatic Gain Control  Automatic Frequency Control  Memory to save the settings of the PLL

Milestones Design of Front-End Low-Noise and Radiation Tolerant Readout Systems 15 Milestones

Conferences Design of Front-End Low-Noise and Radiation Tolerant Readout Systems 16  Targeted conferences: 2010  PRIME 2010 – July 2010  TWEPP 2010 – September 2010  DCIS 2010 – November  IM3STW 2011– June 2011  DATE 2011– March 2011  ITC 2011– October 2011 Dissemination

Conclusions Design of Front-End Low-Noise and Radiation Tolerant Readout Systems 17  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

Design of Front-End Low-Noise and Radiation Tolerant Readout Systems 18 Thank you for your attention.