versatile link plus project - twepp2016

Tips to implement the VL+ in your detector

Francois Vasey

Outline

● VTRx+ front-end module

● Back-end Tx, Rx and TRx modules

● Passives

● System

ATLAS, 14 Nov 2019 [email protected] 2

FPGA

TRX

BackendVTRx+

SERDES

SERDES

SERDES

SERDES

Passives

Front-end Back-end

Useful references from TWEPP-19

P. Moreira

S. Biereigel

S. Kulis L. Olantera


F. Vasey

TWEPP-2019 talks: https://indico.cern.ch/event/799025/timetable/#20190902

https://indico.cern.ch/event/799025/timetable/#20190902

1. VTRx+ Front-End Module


● Back-end Tx, Rx modules

● Passives

● System


FPGA

TRX

BackendVTRx+

SERDES

SERDES

SERDES

SERDES

Passives

Reference:

[1] “Versatile Link Plus VTRx+ Specification”, EDMS Document 1719329

[2] “Versatile Link Plus Application note”, EDMS Document 2149674

1.1 VTRx+ Assembly on Host Board

● VTRx+ is mounted upside-down on host board

● Mechanical fixing and fiber strain relief depend on application and environment● The users decide

● Example from CMS OT


1.2 VTRx+ Pigtail

● Pigtail being finalized● Rad hard fibre

● 5 individual fibres in loose tube

● MT termination

● Not dismountable

● Connection with MT Spring Clamp● Dense connectivity at expense of handleability

● Or with MT to MPO adapter● if you have space

ATLAS, 14 Nov 2019 [email protected]

2. Back-End Tx, Rx Modules



● Passives

● System


FPGA

TRX

BackendVTRx+

SERDES

SERDES

SERDES

SERDES

Passives

Reference:

[1] “Versatile Link Plus Backend Array Specification”, EDMS Document 1762899

2.1 Backend Modules with Tightened Specs

● Link power budget is insufficient at end-of-life if using COTS backend components

● VL+ backend modules must have reasonably non-standard specs to close power budget

● Agreement reached with Samtec Inc.● VL+ system must use custom Firefly module at backend

● CERN-specific reference: CERN-B-XXX-XXX-X-X-X-X (see next slide)

● Choice of pigtail length, ribbon type, heatsink type, Tx Rx or Y-module etc.

● Fixed prices irrespective of purchase origin and order volume, 10pcs MOQ

● First 50pcs of each unique configuration (ribbon, heatsink, performance grade, except pigtail length) are more

expensive

● Letter of Authorization from CERN required to link institute to VL+ project

● Prices valid until June 2024, directly through Samtec (not through distributors)

● Expect to release parts for use in VL+ system in Jan-2020

● Preparing list of authorized institutes in the meantime (Q4-2019)

● Electronics coordinator have contacted users to get quantity forecasts (Q4-2019)

● Prices will be communicated to all authorized institutes

● Until end-2019● Users to procure standard Firefly ECUO 14G parts at local market prices

● ECUO and CERN-B parts are pin-compatible

● CERN-B parts provide necessary margin for experiment lifetime and radiation-induced degradation of front-end, but

ECUO parts will work fine for prototypes


2.2 Firefly CERN-B reference code


• VL+ trunk cable will be

terminated with female MTP

connectors at backend (TBC)

• Either MTP12 or MTP24

*

References:

[1] Samtec product brief and engineering drawings: FireFly™ CERN-B https://edms.cern.ch/ui/#!master/navigator/document?P:1930058715:1947672741:subDocs

[2] Samtec datasheet: FireFly™ CERN-B, under NDA. Contact [email protected]

*

https://edms.cern.ch/ui/#!master/navigator/document?P:1930058715:1947672741:subDocs

mailto:[email protected]

3. Passives



● Passives

● System


FPGA

TRX

BackendVTRx+

SERDES

SERDES

SERDES

SERDES

Passives

Reference:

[1] “Versatile Link Plus Passive Optical Components Specification”, EDMS Document 1762900

3.1 Cabling plant

● VTRx+ interface (4Tx 1Rx) and Backend interface (12Tx 12Rx) are fixed by VL+ project

● Link length and number of breakpoints are specified by detector● Up to 150m, up to 5 breakpoints

● The shorter the length and the fewer the breakpoints, the better the power margin

● Need aggregation (fan-out) and reshuffling (shuffle) functions in the cabling plant● Keep diversity low and manageable

● Select from «catalogue» three types of cables

● Fanout (naked or rugged)

● Shuffle

● Trunk


Frozen, see part 2Frozen, see part 1

with two types of fibre

• Standard Rad Tolerant

• Rad Hard

3.2 Design example (1/2)

● CMS Outer Tracker


PP0 PP1 PPShelf

Naked fan-out Fan-out patch cord Trunk cable

24 24

12

24

PPVTRx+

12

12

PPVTRx+

12

12

PPVTRx+

12

12

PPVTRx+

12

12TO F

RO

NT-E

ND

TR

AN

SCE

IVE

RS

TO B

AC

K-E

ND

TR

AN

SCE

IVE

RS

TRx+

VTRx+ Rad Hard Fibre Standard Rad Tol Fibre

3.2 Design example (2/2)

● CMS ECal


Fan-out patch cord Trunk cable

TO F

RO

NT-E

ND

TR

AN

SCE

IVE

RS

TO B

AC

K-E

ND

TR

AN

SCE

IVE

RS24

12

12

12

12

24

24

24

24

24

12

PP1 PPShelf

24 24

24 24

TRx+

TRx+

TRx+

Shuffle patch cord

PPVTRX+

VTRx+

PP0

Standard Rad Tol Fibre

3.3 Passive Plant: Next Steps


● Rad Hard fibre on order● 800km

● Will eventually have to complement this first order to match total needed length (will require user input !)

● Market Survey for supply of patch cords and assemblies launched (MS-4530/EN/EL)● Fanouts

● Shuffles

● Samples can/must be ordered within MS framework. Users should profit from this opportunity to test their designs

● Expect to freeze portfolio and specs by mid-2020● Preparing list of requirements from all detectors in the meantime (Q4-2019)

● Flavours, parameters, quantities

● Electronics coordinator have contacted detectors to get forecasts (Q4-2019)

● Samples to be ordered in Q1-Q2-2020

● Please participate and fill in survey

● Your last chance to tune the portfolio of parts

● Converge on a shortlist of flavours by Q2-2020

● Expect to launch IT by Q3-2020

● Trunk cables are covered by a more general

Market Survey (MS-4537/EN/EL)

4. System



● Passives

● System


FPGA

TRX

BackendVTRx+

SERDES

SERDES

SERDES

SERDES

Passives

References:

[1] “Versatile Link Plus System Specification”, EDMS Document 1719328

4.1 Power Budget: Two Grades of Links


● Upstream Power Budget is tight. Depending on link length and radiation environment, extended

grade components must be used.

● Best margin achieved for short links with few breakpoints

4.2 Standard or Extended Grade ?

1. Consider VTRx+ environment

If fluences at VTRx+ position are:a. above standard grade levels > select Extended Grade

b. at/ or below standard grade levels: move to step 2

2. Consider Fibre environmentcalculate Radiation Induced Attenuation (RIA) in fibre (choice of standard and rad hard fibre types)

a. If RIA is below 0.5dB > select Standard Grade

b. If RIA is above 0.5dB > select Extended Grade


Tolerance level Dose and fluence (1Mev neutron equivalent)

Standard Grade1 MGy

1 x 1014 neutrons/cm2

1 x 1014 hadrons/cm2

Extended Grade1 MGy

1 x 1015 neutrons/cm2

1 x 1015 hadrons/cm2

3. If unsure, contact VL+ team with:- detector ionising radiation map

- fibre route and patch panel locations

- Position of Cold / Warm transition (if applicable)

To determine fibre type(s), calculate total RIA, and select VL+ grade

5 Conclusion

● VL+ gearing towards production

Users to clarify their needs● Electronics Coordinators have distributed three questionnaires for VTRx+, Firefly, passive plant

● Please indicate:

● For Prototypes: desired quantities

● For Production: estimated quantities,flavours, timescales

● Will be an iterative process

● VTRx+ Preprod Q2-2020, prod starting Q4-2020

● Schedule: https://ep-ese.web.cern.ch/content/lpgbt-vl-dcdc-schedule


https://ep-ese.web.cern.ch/content/lpgbt-vl-dcdc-schedule

versatile link plus project - twepp2016

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