Radiation-Hard Optical Hybrid Board for the ATLAS Pixel Detector

Radiation-Hard Optical Hybrid Board for the ATLAS Pixel Detector

K.K. Gan, H.P. Kagan, R.D. Kass, H. Merritt, J. Moore, A. Nagarkar, D. Pignotti, S. Smith, M. Strang The Ohio State University P. Buchholz, A. Wiese, M. Ziolkowski Universitt Siegen OUTLINE Introduction Result on 4-channel Driver/Receiver with Redundancy Design of new 12-channel Driver/Receiver with Redundancy Summary/Conclusions R. Kass DPF 2011 1 Optical data transmission preferred over copper wire links: optical fibers are lower in mass than copper

higher data transmission rate over long distances (80m) no ground loop between front and back end electronics Optical Transmitter: VCSEL (vertical cavity surface-emitting laser) Optical Receiver: PIN diode Several systems in ATLAS using optical Can be detector packaged in one, four,transmit twelve data channels links. in the radiation environment of the LHC Work ~80m (e.g. pixel & SCT)

~1m R. Kass ~1.85m VCSEL: VDC: PIN: DORIC: DPF 2011 optoboard Vertical Cavity Surface Emitting Laser diode VCSEL Driver Circuit PiN diode Digital Optical Receiver Integrated Circuit 2

Array solution has several major advantages over a single fiber system: compact: more channels in less space obust: 12-fiber ribbon stronger than individual fiber efficient: can reserve 1 in 12 channels for redundancy instead of doubling the number of fibers for a single fiber system VCSEL/PIN array based links are commercially available: 2-fiber ribbon, 12 channel VCSEL/PIN array, 10 Gb/s each 120 GB/s ! 12-channel VCSEL & PIN arrays available from several vendor endors provide reliability and qualification info. ituation better than in 2003 when implementing array based n-detector links for ATLAS pixel detector: We only had to fabricate 272 array-based opto-boards for 1744 pixel modules. R. Kass

DPF 2011 3 We designed an updated version of the VCSEL driver and PIN receiver used in the current ATLAS pixel detector. Added redundancy Possible applications include current ATLAS pixel detector and its upgrade IBL (insertable B-Layer) in 2013-14 Experience gained from the development/testing of new chips could help the development of on-detector array-based opto-links for high luminosity up grades to the LHC Submitted 1st prototype chip in Feb. 2010 process: 130 nm CMOS R. Kass DPF 2011

4 Chip Content VCSEL: Vertical Cavity Surface Emitting Laser diode PIN: PiN diode The Decoder decodes bi-phase mark encoded clock & commands Design Photo VCSEL Driver (spare) VCSEL Driver VCSEL Driver with pre-emphasis VCSEL Driver with pre-emphasis CML Driver with pre-emphasis Decoder (40Mb/s) Decoder (40Mb/s) Decoder (40Mb/s) Decoder (40/80/160/320 Mb/s,

spare) R. Kass DPF 2011 1.5 mm 5 PIN Receiver/Decoder PIN Prototype chip only. R. Kass DPF 2011 6 Command Decoder

Interface Courtesy of FE-I4 of IBL Prototype: majority voting, 3 command decoders Production: majority voting, up to 11 command decoders In prototype chip only R. Kass DPF 2011 7 VCSEL Driver Section Channel Select (3:0)

Set DAC Command Write DAC Bits (7:0)Write Enable (3:0) VCSEL pre-emphasis input added for prototype chip only. main amplitude R. Kass DPF 2011 8 Irradiation Results

2 chips were packaged for irradiation with 24 GeV/c protons at CERN in August 2010 Each chip contains 4 channels of drivers and receivers Total dose: 1.7 x 1015 protons/cm2 Included purely electrical tests to avoid complications from degradation of optical components Long cables limited testing to low speed Observe little degradation of the devices Test card R. Kass chip PIN opto-pack ULM 5 Gb/s DPF 2011

9 Single Event Upset Rate SEU hardend latches or DAC could be upset by traversing charged particles 40 latches per 4-channel chip SEU tracked by monitoring the amplitude of the VDC drive current 13 instances (errors) of a channel steered to a wrong channel in 71 hours for chip #1 Similar upset rate in chip #2 Estimate SEU rate: = 3x10-16 cm2 particle flux ~3x109 cm-2/year @ opto-link location SEU rate ~10-6/year/link R. Kass

DPF 2011 10 Summary 0f 2010 Prototype Chip rototyped 4-channel VCSEL driver & PIN receiver/decoder: ncorporated experience from current opto-links by adding: redundancy to bypass broken PIN or VCSEL channel individual VCSEL current control power-on reset to set VCSEL current to ~ 10mA on power u esults of tests: CSEL driver can operate up to ~ 5 Gb/s with BER < 5x10-13 IN receiver/decoder works even at low threshold radiation with 24 GeV protons to 1.7x1015 p/cm2 Very low SEU rate in latches ~3x10-7/year/link small decrease in VCSEL driver output current R. Kass

DPF 2011 11 2011 PIN Receiver Decoder Chip Decodes 40 Mb/s bi-phase mark (BPM) signal 4 spare PIN receivers for redundancy 8 FE-I4 command decoders Allows remote control by voting between commands received by the 8 FE-I4 command decoders If one of the 8 inner PIN diodes fail signal from one of the 4 redundant channel amplifier outputs can be steered to the digital portion of the failed channel Majority voting of the command decoder values determines the command to be executed Allows working control if only 2 PIN channels are alive R. Kass

DPF 2011 12 2011 PIN Receiver Decoder Chip Spare PIN amplifiers Submitted May 2011 size: 6.5 mm x 1.6 mm 600 m x 900 m control logic 8X DORIC Spare PIN amplifiers R. Kass

DLL + command decoder + LVDS driver 600 m x 900 m voltage regulator 2.5 V 1.5 V DPF 2011 13 2011 PIN Receiver Decoder Chip K.K. Gan R. Kass RD11 DPF 2011 14 14

2011 VCSEL Driver Chip Designed for 8 channel operation up to 5 Gb/s 4 spare VCSEL driver outputs Receives serial data from PIN receiver/decoder (command decoder vote) for configuration If one of the 8 inner VCSELs fail the data signal from the detector can be steered to any of the spare VCSELs 8 bit DAC for remote control of individual VCSEL current Submitted May 2011 size: 1.5 mm x 4.5 mm 15 R. Kass DPF 2011 15

2011 VCSEL Driver Chip R. Kass DPF 2011 16 Summary/ Conclusions Our 2010 4-channel driver/receiver chips with redundancy and other improvements work well 12-channel driver/receiver chips with redundancy submitte in May 2011 Will irradiate chips with 24 GeV protons in September 201 Will Submit 4-channel driver/receiver compatible with high luminosity-LHC in 2012

R. Kass DPF 2011 17 Extra Slides R. Kass DPF 2011 18 VCSEL Driver with PreEmphasis 160 Mb/s Main amplitude Pre-emphasis

Pre-emphasis working with tunable width and height R. Kass DPF 2011 19 Recovered Clock/Data Decoder recovers clock & data from bi-phase mark input stream Decoded clock 320 Mb/s Decoded data R. Kass DPF 2011

20 2010 VDC Results Power-on reset circuit n the present pixel detector an open control line disables 6 opto-links Prototype chip has a power-on reset circuit chips will power up with several mA of VCSEL current Test port can steer signal received to spare VDC/VCSEL can set DAC to control individual VCSEL currents All 4 channels run error free at 5 Gb/s ncludes the spare with signal routed from the other inputs R. Kass

DPF 2011 21

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