Status of front-end electronics for the OPERA Target Tracker Ludovic RAUX Oscillation Project with Emulsion-tRacking Apparatus Status of front-end electronics for the OPERA Target Tracker LAL Orsay S.BONDIL, J. BOUCROT, J.E.CAMPAGNE, A.CAZES, C. de LA TAILLE, A. LUCOTTE, G. MARTIN-CHASSARD, L. RAUX, J.P. REPELLIN BERN University K.BORER, M.HESS Tuesday, 20 May 2003 OPERA Collaboration Meeting - Gran Sasso

OPERA Collaboration Meeting - Gran Sasso Contents Version 2 chip prototype (Reminder) Chip characteristics Measurements (made in collaboration with Bern) Version 3 chip prototype – OPERA-ROC (ReadOut Chip) Conclusion and perspectives Comparison: Version 2 vs version 3 Production schedule Production cost Tuesday, 20 May 2003 OPERA Collaboration Meeting - Gran Sasso

Version 2 prototype front-end chip Ludovic RAUX Version 2 prototype front-end chip 32 inputs (Ch1-Ch32), trigger output + 1 multiplexed charge output Variable gain preamplifier : range 1-3, resolution = 4 bits (1, 0.5, 0.25, 0.125) Fast shaper (tp = 20 ns, G ~ 20) for auto-trigger (1/3 pe) Slow shaper (tp = 100 ns, G ~ 1) for charge measurement On chip track & hold and output multiplexer – Submitted in September 2002 – Received in March 2003 – Validated in April 2003 Technology: AMS 0.8 m BiCMOS Chip area : 10 mm2 Package : QFP100 Power consumption : 250 mW Tuesday, 20 May 2003 OPERA Collaboration Meeting - Gran Sasso

Version 2 chip Tests: summary 32-channel chip (version 2) Preamplifier: Gain correction Input impedance Operational (4 bits): Effective range [0-2.8] 1.5-2k Ohms Auto-Trigger : Fast Shaper tP Fast Shaper Gain Pedestal spread Noise RMS Comparator tP = 20 ns 800mV/pC ( 130 mV/pe) ~ 0.1 pe ~ 1 mV ( ~ 0.01 pe) Operational:  =100 % down to 1/4 pe Charge measurement : Slow Shaper tP Slow Shaper Gain Dynamic range Cross-talk tP = 100 ns 140 mV/pC ( 22 mV/pe) [0-75] pe ~ 40 mV ( ~1.5 pe) 0.5 mV ( ~0.02 pe) ~ 1% 1 p.e. = 160 fC @ 106 The version 2 chip performance suits the Target Tracker requirements Validation procedure is reported in OPERA note 40 Tuesday, 20 May 2003 OPERA Collaboration Meeting - Gran Sasso

Version 3 chip (Reminder) Version 3 chip – OPERA ROC(ReadOut Chip) Significant improvements Reduced cross-talk (decreased preamplifier input impedance) Reduced pedestal spread in charge measurement and autotrigger Main new features included: (tested in a previous test chip: « meccano chip ») New preamplifier architecture with low input impedance and increased gain correction range (on 6 bits) : from 0 to ~ 4 New Fast Shaper structure (differential configuration amplifier) : low offset New Slow Shaper structure (Sallen-Key structure and differential configuration amplifier): low offset Improved Track & Hold based on Widlar structure Register to identify the triggered channel – Submitted in November 2002 – Received in March 2003 – Validated in May 2003 Technology: AMS BiCMOS 0.8 m Chip area : 10 mm2 Package : QFP100 Power consumption : 185 mW Tuesday, 20 May 2003 OPERA Collaboration Meeting - Gran Sasso

Version 3 chip test: Preamplifier Preamplifier performance Preamlifier Gain (G=1) : 95 mV/pC (15 mV/pe) (1 pe=160 fC @ 106) Gain Correction : Operational : 6 bits => 64 levels of corrections (2,1,1/2,1/4,1/8,1/16) Effective range: from 0 to 3.5 (0 to ~ 4 expected) Possibility to switch OFF/ON any individual channel Noise : < 0.01 pe @ 10 ns and 200 ns Input Impedance : Zin~110 Ohms (1.5k-2k Ohms in Version 2) iin iout Slow shaper 0.01 pe Fast shaper Tuesday, 20 May 2003 OPERA Collaboration Meeting - Gran Sasso

Version 3 chip tests: Auto-trigger (I) Fast Shaper : Fast Shaper Gain: ~ 4.5V/pC (~800 mV/pe) Fast Shaper Peaking time: tP ~ 15 ns Noise RMS: ~ 1 mV (~ 0.01 pe) Comparator : Efficiency:  =100 % down to 1/10 pe (goal: 1/3) Offset spread: ~  0.02 pe : 2 sources => Fast shaper (main contribution) and Comparator (negligible) 0.02pe Fast Shaper Vout vs Qin Vout (V) 0.12 p.e. 12 p.e. 1.2 p.e. Gain 2:1 Time (ms) Gain 3 Gain 1 0.02pe Tuesday, 20 May 2003 OPERA Collaboration Meeting - Gran Sasso

Version 3 chip tests: Auto-trigger (II) Comparator : Time walk : Δt~15 ns 15 ns Hit Register : Allows to Identify the triggered channel : Operational Crosstalk sensitive for Qinj>20pe Tuesday, 20 May 2003 OPERA Collaboration Meeting - Gran Sasso

Version 3 chip tests: Charge measurement (I) Slow Shaper Vout vs Qin Time (s) Measured Performance: Dynamic Range: Linearity: < 1% [0-20] pC  [0-125] pe Slow shaper Gain (G=1): ~125 mV/pC (20 mV/pe) Slow shaper peaking time: tp~160 ns Dynamic range [0-75] pe Dynamic range [0-125] pe Version 2 Version 3 Tuesday, 20 May 2003 OPERA Collaboration Meeting - Gran Sasso

Version 3 chip tests: Charge measurement (II) Measured Performance: Track & Hold: Fully Operational : Widlar Structure: OK Noise RMS : ~ 1.5 mV (0.07 pe) Pedestal spread :  6 mV ( ~ 0.3 pe) peak-to-peak (~ 1 mV expected) Version 2 20 mV Version 3 6 mV Tuesday, 20 May 2003 OPERA Collaboration Meeting - Gran Sasso

Version 3 chip tests: Cross-talk Channel-to-Channel cross-talk : 2 contributions : Capacitive coupling between neighboring channels: less than 0.3% (low input impedance) Systematic injection in all channels (comes from power supplies): less than 0.5% Trigger-Charge cross-talk Cross talk Trigger measurements negligible  1/100 sampling time Neihgboring channels Qinj=1/3 pe Tuesday, 20 May 2003 OPERA Collaboration Meeting - Gran Sasso

Comparison :Version 2 vs Version 3 185 mW 250 mW Consumption QFP 100 Package Range 0-3.5 , 6-bit resolution : 0 + (2, 1, 1/2, 1/4, 1/8, 1/16) Zin ~ 110  3 pF alternate Range 1-2.8 , 4-bit resolution : 1 + (1, 1/2, 1/4, 1/8, 1/16) Zin ~ 1.5 to 2 k  None Gain correction Input impedance Input for test pulse tP=15 ns 4.5 V/pC (700 mV/pe) ~ 0.03 pe ~ 1 mV (~1/1000 pe) Operational:  =100 % down to 1/10 pe 15 ns Operational tP=20 ns 800 mV/pC (130 mV/pe) ~ 0.1 pe ~ 1 mV ( ~0.01 pe) Operational:  =100 % down to 1/4 pe Fast Shaper tP Fast Shaper Gain Pedestal spread Noise RMS Comparator Time walk Hit register OPERA-ROC (version 3 chip) Version 2 chip [0-12pC] ([0-75pe]) ±20 mV (± 1 pe) ~ 0.5 mV (~0.02 pe) tP=110 ns 140 mV/pC (22 mV/pe) ~1% [0-20pC] ([0-125pe]) ±6 mV (±0.3 pe) ~ 1.5 mV (~0.07 pe) tP=160 ns 125 mV/pC (20 mV/pe) <1% Dynamic range Slow Shaper tP Slow Shaper Gain Cross-talk 1 p.e. = 160 fC @ 106 Preamplifier Auto-trigger Charge measurement Tuesday, 20 May 2003 OPERA Collaboration Meeting - Gran Sasso

Conclusion: Version 2 vs Version 3 Both versions suit the Target Tracker requirements and are validated Both versions can be used without any new iteration But version 3 improves significantely version 2 The chip must to be tested with the Bern Front-end board Prototype Proposal : OPERA ROC (Version 3) is considered as the baseline chip Tuesday, 20 May 2003 OPERA Collaboration Meeting - Gran Sasso

OPERA Collaboration Meeting - Gran Sasso Production schedule Production could start in July 2003 Delivery expected in Orsay in October 2003 Test of the mass-produced chips will take place in Orsay in November 2003: Bench-test set-up has started Chips available for the collaboration by January 2004 Tuesday, 20 May 2003 OPERA Collaboration Meeting - Gran Sasso

Production cost estimation Both versions are cost equivalent (same area: ~10mm²) Silicon : 2800 dies (assuming 80% yield and 200 spares) : 48 k Euros Package : PQFP-100 : 7 k Euros Total : 55 k Euros (~ 0.7 Euros per channel) Tuesday, 20 May 2003 OPERA Collaboration Meeting - Gran Sasso

Version 3 chip tests: Auto-trigger (I) Fast Shaper : Fast Shaper Gain: ~ 4.5V/pC (~800 mV/pe) Fast Shaper Peaking time: tP ~ 15 ns Noise RMS: ~ 1 mV (~ 0.01 pe) Comparator : Efficiency:  =100 % down to 1/10 pe (goal: 1/3) Offset spread: ~ 0.05 pe : 2 sources => Fast shaper (main contribution) and Comparator (negligible) Fast Shaper Vout vs Qin Vout (V) 0.12 p.e. 12 p.e. 1.2 p.e. Gain 2:1 Time (ms) Tuesday, 20 May 2003 OPERA Collaboration Meeting - Gran Sasso