VITA 48 aka VPXREDI

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VITA 48 (aka VPX-REDI)
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Agenda

• What is VITA 48?
• Two Level Maintenance VITA 48
• VITA 48 Card Pitches and Dimensions
• PWB Commonality
• VITA 48.2 Wedgelock locations
• VITA 48.3 In-board Liquid Connectors
• VITA 48 Status and Issues
• CWCEC Plans for VITA 48 use

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What is VITA 48 ?

• Complementary mechanical standard to VITA 46
  (which is based on IEEE 1101.1 and .2 form
  factors)
• Title is Mechanical Specification using
  Ruggedized Enhanced Design Implementation (REDI)
• V48.0 (base), V48.1 (air cooled), V48.2
  (conduction), V48.3 (liquid cooled)
• Primary objectives
• Increase useable PWB area PWB thickness
• Improve thermal management (AC, CC, LFT)
• Enable functional density increase
• Include two level maintenance (2LM) features
• Mechanical interchangeability of cards
• Sponsors Boeing, Curtiss-Wright, Mercury (Chair
  Randy Banton, Editor Mike Gust)

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Two Level Maintenance (2LM)

• Traditional Three-Level Maintenance
• Chassis (LRU) removal replacement (RR) at
  Organizational level (O-level)
• Requires ESD/Handling protection at box interface
• Fault isolation to box
• Requires sparing boxes
• RR cards at Intermediate level (I-level) shop
• I-level shop is expensive, vulnerable and hard to
  transport
• Card repair at Depot level

• Two Level Maintenance
• LRM (line replaceable module/card) RR at the
  O-level
• Requires ESD/Handling protection at the
  module/card level
• Fault isolation to the module/card
• Requires sparing modules/cards
• I-level shop not required
• LRM repair at Depot level
• Estimated 50-70 less costly operation support
  (OS) than 3LM, plus reduced weight and volume
  (logistics footprint)
• 2LM is not without issues, e.g. LRM connectors
  and conduction thermal interfaces are relatively
  fragile

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Two Level Maintenance (2LM)

• Traditional Three-Level Maintenance

Two-Level Maintenance
Courtesy Jim Robles (Boeing)
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VITA 46/48 2LM Features
ESD-protected Module Connector (from VITA 46)
Meets ESD requirement from ANSI/VITA 47 (15 kV
air discharge with lt20 V on any signal contact)
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VITA 48 2LM Features
VITA 48 adds covers over Electronics for ESD and
handling protection (Note that using covers for
air cooled cards may require licensing Mercury
patents)
Safety Ground (provided via alignment modules)
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What is VITA 48 ?
Air cooled 3U
2LM LFT 6U
2LM Conduction cooled 6U
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VITA 48 Module Envelopes
Compared to 0.7 in IEEE 1101.1 and .2

• 0.03 card-to-card separation (with covers)

• gt0.03 card-to-card separation

• 0.1 card-to-card separation

Type 1 Two level maintenance compatible, i.e.
full covers on both sides Type 2 One or more
covers absent, therefore not fully two level
maintenance compatible
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VITA 48 Card to Card Distances

• 0.8, 0.85, and 1 pitch cards can be mixed in
  same chassis/ backplane
• Depending on backplane pitch, cards may take up
  gt1 slot, e.g. 1 pitch cards in 0.8 pitch
  backplane.
• Card to card distance varies with backplane
  pitch, card thickness, and presence/absence of
  covers.

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VITA 48 1 Pitch

• 1 pitch allows more space on primary side for
  cooling
• Also allows more space on secondary side for
  thicker PWBs, taller parts, and cooling

Section view see next slide (rotated 180)
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1 Pitch Allocation
0.660 primary side
2 mm (0.08) increase
0.18 PMC height restrictions
1.0 pitch
0.310 secondary side
0.97 module thickness

• Additional 0.27 module thickness over 0.8
  pitch (or 0.7 module thickness)
• 0.15 on secondary side - for increased PWB
  thickness, higher components and cover, if
  required
• 0.12 on primary side - for increased PWB area,
  improved thermal management and cover, if
  required
• 5-6 sq. in. additional PWB area (topside near
  front panel, low height parts lt 0.08)
• Allows up to 40 increase in CC power
  dissipation and 10 in power density over 0.8
  (mainly due to improved cooling from secondary
  side cover)
• Needs higher XMC connector on basecard (2mm
  higher) Samtec has committed to using an
  interposer board to increase the height.

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Front Panel Keep-out
1 pitch offers 5-6 sq. in. additional PWB area
for low height parts
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0.85 Pitch Allocation
0.54 primary side (1101.1/.2)
0.85 pitch w/covers
0.8 pitch (1101.1/.2)
0.58 primary side
0.18 PMC height
0.7 module thickness (1101.1/.2)
0.82 module thickness w/covers
0.16 secondary side (1101.1/.2)
0.24 secondary side

• 0.85 pitch leverages 0.8 pitch designs and
  adds covers for 2LM
• 0.8 pitch for non-2LM versions (VITA 46) 0.85
  pitch for 2LM (VITA 48)
• Thicker cover on secondary side for improved CC
  thermal management
• 0.8 and 0.85 pitch cards fit into 1 pitch
  slots
• Why have 0.85 pitch ? Increased functional
  density compared to 1 pitch

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PWB Commonality Goals
Existing CWCEC approach for 1101.x
0.85 pitch LFT (2LM)
0.8 pitch Air cooled
0.8 pitch Conduction cooled
0.85 pitch CC (2LM)
Common slot mechanics
1 pitch LFT (2LM)
1 pitch Air cooled
1 pitch Conduction cooled
1 pitch CC (2LM)
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VITA 48.2 Wedgelock Locations
Primary side wedgelock (same as 0.8 and 0.85
pitch formats)
Secondary side wedgelocks
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VITA 48.3 In-Board QD Location
Outer alignment blocks removed to accommodate
liquid QD connectors (to fit in ATR chassis).
Concerns raised Increased tolerances for
connector mating, no connector support during
wedgelock expansion.
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VITA 48 Status

• VITA 48.0 (base) and 48.1 (air cooling applied to
  V46) have completed several ballots approved,
  but some issues left to resolve.
• VITA 48.2 (conduction cooling applied to V46)
  completed 1 ballot not approved yet.
• VITA 48.3 (liquid cooling applied to V46) still
  being developed.
• Outstanding Issues
• Rule requiring electrically conductive card edge
  interface (disallows anodized aluminum at card
  edge).
• Interposer required for 12 mm stand-off height of
  XMC connectors on 1 pitch
• In-board QD impacts
• Sub-rack requirements for combination of CC and
  LFT modules.

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CWCEC Plans for VITA 48 Use

• VITA 46/48 products to have 2LM designed in, e.g.
  no PWB layout/routing impact for covers.
• If AC covers used, need to obtain patent licenses
  from Mercury.
• VITA 46 DSP products using V48 1 pitch for
  increased useable PWB area
• LFT designs to follow V48.3 (incl. ANSI/VITA 47)

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Different Backside Heights (0.8)
Less backside height (than V48 CC or LFT) due to
desire to use 1101.10 handles
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Different Backside Heights (0.85)
Less backside height (than V48 CC or LFT) due to
desire to use 1101.10 handles