E.Hazen Slides on faraday cage, PC boards, cabling Mezz Boards, - - PDF document

E.Hazen Slides on faraday cage, PC boards, cabling

Mezz Boards, Cabling, Faraday Cage (general) mezz_evo.pdf Evolution of Mezzanine PCB Design ext_cables.pdf External Cable Proposal JO1.pdf Noise Coupling (J.Oliver) Module 0 JO2.pdf Shield Plane in F-Cage mezz_conn_mod0_ec.pdf Mod 0 Endcap Faraday Cage with Shield and connector endcap_mod0_exp.pdf Mod 0 Endcap Faraday Cage Exploded endcap_shield.pdf Mod 0 Endcap Faraday Cage Shield Plate HH_MEZZG.pdf Rev G (3x8) Mezzanine Lite Board Dimensions

1 of 3 9/29/00 3:38 PM Atlas Week October 2000 http://ohm.bu.edu/bmc/slides/atwoct00/

HH_MEZZH.pdf Rev H (3x8) Mezzanine Lite Board Dimensions csm_adapter.pdf CSM Adapter Board mod0_cables.pdf 36-Pin Cables Production Proposals fig_cprime.pdf "2 Box" Shielding Concept new_fcage.pdf Endcap F-Cage for Production - Proposed new_fcage2.pdf Endcap F-Cage for Production - Proposed barrel_prod_1.pdf Barrel F-Cage for Production - Ideas mezz_conn_prod.pdf 36 Pin Connector Details

2 of 3 9/29/00 3:38 PM Atlas Week October 2000 http://ohm.bu.edu/bmc/slides/atwoct00/

ship_box.pdf Hedgehog PCB Shipping Box

3 of 3 9/29/00 3:38 PM Atlas Week October 2000 http://ohm.bu.edu/bmc/slides/atwoct00/

• RJ-45 connectors for JTAG and TDC
• 2mm header connectors
• Board shrunk 8mm to fit inside patch panel
• 10 produced in June 2000

No Photo

• Change from 4-6 layers, 2 ground planes
• Noise now limited by clock pickup on hedgehog
• Worked pretty well but noise levels high
• All external signals moved to 36-pin connector
• 4 boards produced in Sept 2000
• 3 boards under test on chamber at Harvard-
• Switch to AMT-1 TDC
• Shorten board and move connector for

compatibility with endcap chamber faraday cage

• Now being tested!

Rev D - Oct 99

• 10 produced

Rev E - June 00 Rev F - July 00 Rev H - Sep 00 Rev G - Aug 00 works well but AMT-0 locking is problematic

ATLAS

MDT Electronics

ATLAS Week, October 2000 - E. Hazen

Mezzanine Lite Evolution

Optical Fibres DC Power Chamber Service Module

Latest mezzanine board layout Connector close-ups We propose to eliminate the patch panel and mount a single interface connector on each mezzanine board, with one cable per board to the CSM. We have prototyped and tested this scheme (report by J.Guimaraes/J.Oliver) Current Status: Electrical concept proven. Connectors found - some mechanical issues on chambers Halogen-free cables found require further study ATLAS

MDT Electronics

External Cable Connections to MDT

ATLAS Week, August 2000 - E. Hazen

Noise coupling from TDC (digit al) t o analog input s

TDC TDC ASDs ASDs

• Dominant frequency range

5 MHz - 8 0 MHz (and beyond)

• Magnet ic (induct ive) coupling :

Current loops due t o common mode component of LVDS signals int o cable capacit ance Digit al power/ground current loop

• Elect ric (capacit ive) coupling :

Volt age noise on digit al power/gnd planes, common mode LVDS volt age.

• Noise coupling is predominant ly down

down t o MDTs and Hedgehogs

TDC TDC ASDs ASDs

c) Aluminum shield plane at t ached t o faraday cage

Hedgehog PCB Mezz PCB Connector to CSM F-Cage Cover (Cover not shown) Hole in Cover New Shield

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ATLAS Week, October 2000 - E. Hazen

Module 0 Modifications (endcap)

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ATLAS Week, October 2000 - E. Hazen

MDT Electronics

Module 0 Endcap Faraday Cage - Exploded View

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MDT Electronics

ATLAS Week, October 2000 - E. Hazen

Endcap Faraday Cage (mod 0) Shield Plate

Adapter box needed to test chambers before final CSMs installed

• Convert 36-pin cables to RJ-45 for CSM-0
• Connect JTAG daisy-chain
• Digital and Analog Power Distribution

Prototype for 4 Mezzanine Boards built and tested Final version for 18 Mezzanine Boards - design underway JTAG in JTAG out Mezz 1 Mezz 2 Mezz 3 Mezz 4 TDC 1 TDC 2 TDC 3 TDC 4 DC Power

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MDT Electronics

ATLAS Week, October 2000 - E. Hazen

"CSM Adapter" for Testing

Lab Testing - use IEEE-1284 (parallel printer) type "CC" cables: Cheap, shielded twisted pair cable with reasonable performance. For production, we need a flat, shielded, zero-halogen cable.

Amphenol Spectra-Strip has quoted 15/pair halogen-free, shielded and jacketed US$ 346.19/CFT ($ 11.36/m) (quote was for 5000 ft; our total is about 30k ft) Connectors and labor add about $7 per cable. Estimated total is about $200k for 15k cables, total 10km length Original scheme with patch panel was about $180k (excluding design).

So, up to the CSM the price is comparable.

IEEE-1284 std cable construction http://www.connectpro.com/pccables.html

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MDT Electronics

ATLAS Week, October 2000 - E. Hazen

36-Conductor Cables/Connectors

TDC TDC ASDs ASDs

c ‘) Faraday cage enclosing hedgehog - Mezz card in individual box (G.Hert en)

Box 1 - shield over hedgehog PCB shield over mezzanine PCB Box 2 - This is the "2 box" idea some of you may have heard about... 36-pin connector One box covers the hedgehog PCB Second box covers the mezzanine PCB

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MDT Electronics

ATLAS Week, October 2000 - E. Hazen

Endcap Faraday Cage Proposal

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MDT Electronics

ATLAS Week, October 2000 - E. Hazen

Endcap Faraday Cage Proposal

What about Barrel Chambers? Propose to use same "2 box" scheme.

Mezz board shield Hedgehog board shield Cable Exit Options:

• 1. End of Mezz shield
• 2. Over spacer (top view)

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MDT Electronics

ATLAS Week, October 2000 - E. Hazen

Barrel Chamber Faraday Cage

The IEEE-1284 std connector ("mini-centronics") is an attrative choice. The problem is that it isn’t infinitely small! Only 34mm is available for the "top exit" idea on the endcape chambers Worst case for endcap: 4x6 8.5 degree chamber 10mm is left for cable exit. This is okay, but: No strain relief for cable is provided No latching mechanism for connector is provided (we can easily design a small sheet metal retainer)

Envelope Limit Clearance 34.0 mm Mezz Shield PCB 11.0 mm 13.0 mm 10.0 mm Mezzanine PCB Shield

Barrel Chambers: Right-angle exit between mezzanine boards?

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MDT Electronics

ATLAS Week, October 2000 - E. Hazen

Mezz-CSM Connector: Mezzanine End

Each box holds two PCBs Connectors protected with cardboard tubes Folds up then slips inside sleeve Size: 6 x 24 x 36 cm Cost (100) US $4.37

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MDT Electronics

ATLAS Week, October 2000 - E. Hazen

Hedgehog Board Shipping Boxes