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Scuola di Dottorato di Scienze – Corso di Dottorato in Fisica e Astronomia Ciclo XXVIII. GEMMA ( GEM M ixed- signal A sic ): Design & Developing. Second Year Ph.D . Activity Report. Alessandro PEZZOTTA 26 September 2013. Tutor: Prof. A. Baschirotto.
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Scuola di Dottorato di Scienze – Corso di Dottorato in Fisica e Astronomia Ciclo XXVIII GEMMA (GEMMixed-signalAsic): Design & Developing Second YearPh.D. Activity Report Alessandro PEZZOTTA 26 September 2013 Tutor: Prof. A. Baschirotto Emails: a.pezzotta1@campus.unimib.it, alessandro.pezzotta@mib.infn.it
Outline • The application: Triple-GEM detector • Project Time Evolution • Main Design Features • Layout and Post-Layout Simulations • GEMMA Overall Performance • Future perspectives Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
Outline • The application: Triple-GEM detector • Project Time Evolution • Main Design Features • Layout and Post-Layout Simulations • GEMMA Overall Performance • Future perspectives Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
The Application • The GEM detector • Belonging to MPGC family • Employed for tracking, time-of-flight, counting, beam monitoring measurements • Main features • High count rate: > 106 cps • Low-cost • Adaptability • Portability Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
Existing Read-Out Systems • All the systems now in use have been re-adapted from other applications: • CCDs • Semiconductor Detectors • Multi-Wire Chambers • Not exploiting the full GEM detector potential • Uniquely analog or digital systems • Limited number of detecting channels included on a single chip Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
The MainIssue • The Pixellated Output • It can be adapted according to measurement necessities • Variable Pixel Parasitic Capacitance • Issues for read-out • Adaptability • Efficiency • Speed Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
Outline • The application: Triple-GEM detector • Project Time Evolution • Main Design Features • Layout and Post-Layout Simulations • GEMMA Overall Performance • Future perspectives Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
First Attempt: GEMINI v1 Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
GEMINI v1 Problem Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
Why GEMMA? • Problems faced in the first version tests • Decision to make a second version, GEMMA • CMOS technology changed (and related software) to 180nm AMS IBM, more stable and reliable • Re-adjustment of specifications • Complying with updated detector performance • Channel number increased to 16 (instead of 8) • LVDS digital outputs and analog output for each channel Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
Updated System Requirements Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
Outline • The application: Triple-GEM detector • Project Time Evolution • Main Design Features • Layout and Post-Layout Simulations • GEMMA Overall Performance • Future perspectives Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
GEMMA Channel Scheme Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
GEMMA MainBlocks • Charge-Sensitive Preamplifier • Two-Stage Miller OTA • 65 dB DC-Gain • 320 MHz UGBW • 100 V/µs SR • 4.3 nV/√Hz IRN • 1.5 mWPower • Comparator • Single EndedMirrored • 0.9 mV offset • 700 uWPower • R-2R Resistive Ladder DAC • 9-bit resolution • 500 mV full scale • 1.2 mV LSB • Sets the comparatorthreshold • Tuning machine for CFcap • 5-bit resolution • Switched-off duringmeasure • 5% MaxCapacitanceerror • Reset switches • High speed • Lowchargeinjection • Low on-resistance • A2D & D2A Level Shifters • Interface elements • Digital Supply 1.8 V to 0 V • Analog Supply 1 V to -1 V • Negligiblesignal time delay • I2C Interface • Setting the DAC input words Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
GEMMA Digital Layout • The digital blocks substrate has been isolated for strongly reducing coupling with the analog, implementing a Triple-Well structure Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
Outline • The application: Triple-GEM detector • Project Time Evolution • Main Design Features • Layout and Post-Layout Simulations • GEMMA Overall Performance • Future perspectives Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
GEMMA Layout Area = 6.89 mm2 Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
GEMMA SimulationsSettings • ParasiticExtractionafter Layout Procedure • Simulationincludingthoseparasitics • Input Parameters for 100 Monte-Carlo iterations • Pixel Capacitance 40 pF • Chain of Minimum (30 fC) and Maximum Input SignalPulses(500 fC) • Detector first 2 e-threshold(-2.5 mV with 0 mV Input Signal common mode) Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
GEMMA SimulationsResults • 30 fCsimulation Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
GEMMA SimulationsResults • 500 fCsimulation Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
Outline • The application: Triple-GEM detector • Project Time Evolution • Main Design Features • Layout and Post-Layout Simulations • GEMMA Overall Performance • Future perspectives Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
GEMINI v1 vs GEMMA Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
Outline • The application: Triple-GEM detector • Project Time Evolution • Main Design Features • Layout and Post-Layout Simulations • GEMMA Overall Performance • Future perspectives Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"
Future Perspectives • The design hasbeensent to the foundry last weeks • Expected to come back in January 2015 • 40 packagedsamples(CeramicQFP 144 pins) • In the meanwhile • Designing a GEMMA compliantread-out system (Detector Chip Modulesand Motherboard) • Setting up an irradiation test to verify the GEMMA under-radiation performance • The first version (GEMINI v1) hasbeencorrected and re-sent to the foundry • Expected to come back in a fewdays • Tests on first prototypeshouldnow be possible! (finger crossed) Alessandro PEZZOTTA "GEMMA (GEM Mixed-signal Asic): Design & Developing"