Digital Control Links Status and Plans

Digital Control Links Status and Plans K. Gill 5/11/03 http://cms-tk-opto.web.cern.ch/cms-tk-opto/control/esr/

Outline Overview of system Functional requirements Specifications Components Power budget and margins Integration QA/Reliability System tests Radiation resistance Pre-production qualification Lot acceptance Procurement Status Production Flow Delivery schedules

System Overview

System overview Detector Hybrid APV amplifiers pi pelines 128:1 MUX MUX 2:1 optical link boundary TTC Control PLL Delay DCU 4 CCU CCU DOH (a) (f) (e) (d) (b) (c) (g) (h) 8/12 (i) (j) 64/ 96 (l) FEC TRx Module (k) TTCRx processing buffe ring CCU CCU Front-End Back-End Tracker 352 rings (includes 32 new TEC rings) ECAL 368 Preshower 52 Pixels 66 All with redundancy Ref: LECC 2002 cms-tk-opto.web.cern.ch/

Functionality Digital link transmits On clock line (@80Mbit/s) 40MHz clock Trigger Resynch Cal-request Data Clock On data line (@40Mbit/s) 10 missing 1 s Slow control data and tokens Reset signal for front-end Data Reset

Digital Link System Specifications Specification Min Typ Max Notes Wavelength (nm) 1310 Same as analogue links Speed (Mbits/s) 2 80 AC coupled Bit-error-rate 10-12 Jitter (ns) 0.5 rms Skew (ns) 2 Between fibres to/from same digital optohybrids TRx Input/Output ±600mV LVPECL input CML output into 100Ω DOH Input/Output Voltage ranges ±400mV LVDS, differential referred to Vss. Input impedence 100Ω, output should be terminated with 100Ω Reset output from DOH Active low Reset output when no signal detected on DOH input data line for 10 clock cycles

Development Not so many optical channels in this system ~7000 c.f. ~40000 analogue readout channels Aim to minimize indirect costs of development and procurement effort re-use analogue link components where possible laser (low effic.), Laser Driver ASIC (LLD), Fibre, Cables and Connectors Only a few unique parts for digital control link Front-end: photodiodes, Receiver ASIC (RX40), digital optohybrid (DOH) Back-end: Transceiver Benefit from a lot of earlier work on analogue links: component development, qualification (functionality and radiation hardness), procurement DOH also to be made at Kapsch, Vienna Benefit from their experience with Analogue Optohybrid (AOH)

Components Cables/connectors same as readout links 1 12 96 12

Functional reliability: Optical power budget CERN D-OH Optobahn TRx 64/96 8/12 Factors affecting power levels DOH to TRx DC offset I2C dc bias setting (and laser threshold) Laser driver dc gain Laser efficiency Insertion loss + Attenuation Modulation (signal) Input voltage amplitude I2C dc bias setting (and laser threshold) Laser driver gain Laser efficiency Insertion loss + Attenuation TRx to DOH DC offset TRx laser efficiency Insertion loss + Attenuation Modulation (signal) TRx laser efficiency Insertion loss + Attenuation karl.gill@cern.ch 5-11-2003

Power budget detail: DOH to TRx links DOH Tx signal amplitude (dbm) -5-10 -15-20 -25-15 -10-5 0 0 Tx min OMA DOH Tx average launched power (dbm) DOH to TRx links DOH Tx with 16uW/mA MU-sMU and MFS patch panels good margin expected large margin -30-15 -10-5 0 TRx saturation Tx max ave launch power TRx Rx saturation (dbm) TRx responsivity 0-5 -10-15 -20-25 -30 TRx Rx sensitivity (dbm) To avoid saturating TRx-Rx input, we have reduced laser efficiency (16uW/mA in place of 40uW/mA)

Power budget detail: TRx to DOH links TRx Tx signal amplitude (dbm) -5-10 -15-20 -25 TRx Tx average launched power (dbm) -15-10 -5 0 0 TRx with MFS and MU-sMU patch-panels TRx min OMA good margin expected TRx to DOH links -30-15 -10-5 0 Rx40 saturation TRx max ave launch power DOH Rx saturation (dbm) OK margin Rx40 sensitivity 0-5 -10-15 -20-25 -30 DOH Rx sensitivity (dbm) No problems from TRx to DOH

Integration - cabling Control cable will be integrated along with analogue readout cabling E.g. TOB

Plans TOB cabling continued

QA/Reliability Tests

QA/Reliability Active components Lasers Qualification and AVT Done already for analogue links will not cover Photodiodes Qualification and AVT Will present Transceivers Qualification Will present Passive components Fibres Qualification and AVT Done already for analogue links will not cover Cables and Connectors Qualification and AVT Ongoing for analogue links will not cover System (Will present) Eye patterns Bit error rate (BER)

Qualification procedure - PINs Visual Inspection Electrical and Optical Tests Any failures are discussed with the manufacturer Non-destructive pull-test Electrical and optical test Magnetic field test Destructive pull-test

PIN photodiode qualification optical/electrical Dark current b/a 20V Capacitance - voltage Dark Current @ 5V (na) 1.2 0.8 0.4 0.0 0 20 Before After -20V applied 40 60 Device Number 80 100 Capacitance (pf) 2.0 1.6 1.2 0.8 0 100 devices 1 2 3 4 Reverse Bias (V) 5 Dark current b/a 2mA Response speed Dark Current @ 5V (na) 1.2 0.8 0.4 0.0 0 20 Before After 2mA forward current 40 60 Device Number 80 100 Amplitude (a.u.) 1.2 0.8 0.4 0.0 0 10 20 Time (ns) Bias = -2V 10 diodes 30 40

PINs with new gluing process First delivery for pre-production not strong enough Fermionics has changed their assembly process essentially using more epoxy to provide tensile resistance >7N Re-supplied 50 devices 40 pulled with 700g. Only 1 failure 30 parts destructively tested Only 1 fails <7N I pin [µa] @ ~280 µw Responsivity before/after 700g pull test 600 400 200 0 0 10 20 Diode Number 30 Before After 700g 40 These devices considered acceptable Will test non-destructively samples from future series production

PIN AVT procedure for radiation resistance Sampling 3 pin wafers needed for 3800 pins, sample @ 30/wafer Repeat test 10 PINs Procure new wafer 20 PINS 100kGy Gamma 5x10 14 neutrons/cm 2 (room T, biased) Radiation damage Annealing Accelerated ageing (A) Received AVT batch end of July Irrad gamma 25/8, neutrons 28/8 Annealing monitored until 16/9 Interact with manufacturer Failure analysis No Success? >95% pass tests so far? Started aging step 10/10 unirradiated samples No Yes Accelerated ageing (B) Success? Advance clearance 20 irradiated PINs Will stop mid-november Yes Final clearance >95% pass ALL tests?

PIN AVT Neutron data 2V end of irrad 5V end of irrad Effects similar to those seen in past. Some variation between wafers. Fluence estimated to be in range of 0.7-1.4x10 15 n/cm 2 Devices probably sufficiently radiation resistant for CMS Tracker.

Digital Opto-Hybrid Pin photodiodes RX40 receiver chip Optical signals to/from FEC RX TX 26-way NAIS Electrical Connector: - CK/DA to/from CCUMs - Reset to CCUM -I 2 C to/from CCUM Laser diodes Linear laser driver chip

New laser characteristics on v.4 DOH Baseline [Avg] Amp. Laser Output [uw] 2000 1500 1000 500 0 TRx spec Default start-up @ 48 Previous DOH versions Current DOH version 0 20 40 60 80 100 120 LLD Bias Setting Laser Output Amplitude [uw] 350 300 250 200 150 100 50 0 0 Spec Current DOH version 20 40 60 80 LLD Bias Setting Previous DOH versions 100 120 Default is highest gain Saturation of TRx at startup now unlikely with lower laser efficiency

DOH Test System, CERN In Tx A S Datalogger Ref DOH A S I2C PC + LabVIEW Pattern Gen. (Sony) Oscilloscope 1 Level Translator Var. gain in out Reset O-heads DOH under test Tx Rx Oscilloscope 2 O-heads

DOH Test setup Labview output

NGK Optobahn 4-way Backend transceiver module Transceiver pre-production 25 pieces Received end August Test Procedure and setup/software in place 4TRx module m-fec

transceiver test-setup Transceiver test-setup Datalogger DAC+I/O 2 x DOH I2C interface LVDS looped back resets disconnected TX 4 channel var(a) RX TX Pattern generator Level translator TRX under test PC + Labview Oscilloscope 1 (on modified OFEC) RX Power supply Oscilloscope 2 Optical head

4TRx measurement setup Transceiver test-bench very similar to DOH test-setup Measured Electrical output levels Optical levels Jitter and skew Power consumption Effect of variations in power supply ALL PARTS PASSED TESTS Transceiver temporarily mounted on jig attached to modified O-FEC card

4TRx optical properties Example of data from pre-production (25 pieces) -2 ALP Spec. -18 Saturation Spec. Signal Amplitude [dbm] -4-6 -8-10 -12 O.M.A Spec. Sensitivity [dbm] -20-22 -24-26 Sensitivity Spec. -14-12 -8-4 Average Launched Power [dbm] -28-5.0-4.0-3.0-2.0 Saturation [dbm]

System signals Eye patterns Data Clock Reset generation 10 missing 1 s Data Reset

Full link measurements Full link made with DOH, TRX, 100m cable + 3 patch-panels A D MPO-12 out BERT in CK D CK Tx NGK- Optobahn TRx Rx FC/PC Rx Tx CERN DOH Electrical connections 100m optical fibre ribbon Optical power margins measured in each channel optical attenuation increased to point where errors occur or link fails - From DOH to TRx - From TRx to DOH - Clock: ~17.5dB - Clock: ~9.5dB - Data: ~17.5dB - Data: ~10dB Tested for 15 hours without any errors - BER < 3x10-13

Illustration of Sensitivity & Saturation To illustrate the power budget and margins consider BER vs average launched power Typ. DOH data (only cut-off seen) BER 10-2 10-5 10-8 Typ. TRx data Sensitivity spec TRx Sensitivity spec DOH Typical OMA DOH TRx Saturation spec TRx Saturation spec DOH 10-11 -35-30 -25-20 -15-10 -5 Average Launched Power [dbm] Optical modulation amplitude [dbm] BER lower limit due to short measurement period (3 minutes with 40MHz, PRS-7)

Production Status

Production flow Derived from analogue component flow + PINs, TRx, DOH. Fermionics US Buffered Fibre, Rugged. Ribbon Sumitomo JP F428 Jumpers ST IT F451 Lasers Photodiodes Kapsch AT + G&A IT Ericsson SE F416 M-Ribbon Cable QA Buffered Fibre QA Rugged. Ribbon Jumpers Harnesses QA J&H CERN Meyrin Prevessin QA Photodiodes QA Lasers M-Ribbon Cable Harnesses Diamond CH F473 Terminated Fanout Terminated Cable TRx Modules Digital Opto Hybrid Prevessin CERN/CMS Meyrin Amplifier chips Amplifier chips Helix CH NGK JP F469

Production status DOH pre-production Order now in place at Kapsch Met 29/11 in Vienna 40 hybrids to be delivered end January All tested during assemblyusing CERN supplied setup before/after mounting lasers and pins Full qualification at CERN Feb-March If sucessful, DOH series production starts in April 04. Will irradiate v4 CERN hybrids in November/December 2003. TRx series production will start soon. New TRx modules for ECAL order will be re-qualified. PIN series production will start soon. AVT aging step almost finished. All test procedures prepared

Delivery schedule DOH 250 200 150 PRESHOWER PIXEL ECAL TRACKER 900 800 700 600 500 Cumulative ordered for TK Cumulative ordered for Ecal Cumulative ordered for Pixels Cumulative ordered for EE and ES 100 400 300 50 200 100 0 Dec-03 Feb-04 Apr-04 Jun-04 Aug-04 Oct-04 Dec-04 Feb-05 0 Dec-03 Feb-04 Apr-04 Jun-04 Aug-04 Oct-04 Dec-04 Feb-05 4-TRx 180 160 140 120 100 80 60 40 20 0 PRESHOWER PIXEL ECAL TRACKER Jul-03 Sep-03 Nov-03 Jan-04 Mar-04 May-04 450 400 350 300 250 200 150 100 50 0 Cumulative ordered for TK Cumulative ordered for Ecal Cumulative ordered for Pixels Cumulative ordered for Preshower Jul-03 Sep-03 Nov-03 Jan-04 Mar-04 May-04

Conclusions Control link specs frozen earlier in 2003 PINs, DOH, TRx Available on EDMS Shares many parts/procedures with analogue readout links QA/test procedures and schedules written, test-equipment ready Cabling/integration/traceability in parallel with analogue readout links Procurement started for all parts specific to the digital control links PIN photodiodes (Fermionics, USA) Pre-Production Qualification complete Advance validation test (AVT) almost complete Lasers (ST, Milan) Low efficiency lasers integrated into schedule. 100 parts made. DOH (Kapsch, Vienna) CERN Prototype Version 4 (Narrow Pixel request) delivered/tested Kapsch Order finalized. TRx (NGK Insulators, Japan) Pre-Production Qualification almost complete Integration of TRX onto mfec done Small number of final links (~10) available now if needed for test-systems