DOM MB Rev 4'2 to Rev 5'0 Changes

1
DOM MBRev 4.2 to Rev 5.0 Changes

• April 26, 2004
• Gerald Przybylski
• Lawerence Berkeley National Laboratory

2
History

• Rev 1, January 3, 2003, Translation from OrCAD
• Rev 2, April 9, 2003, Booting Memory troubles
• Rev 3, September 2, 2003, Clamping troubles
• Rev 4.1, February 3, 2004, 110 changes
  incorporated
• Rev 4.2, March 15, 2004, 12 more changes

3
Status Requirements

• Rev 4.2 Meets Performance Requirements
• BOM Mature, Minimized, Qualified
• Last batch 20 cards not loading errors, 1
  solder bridge, 1 cold solder, 1 tombstone.
• Mechanical Tweaks
• Little Time Left for Improvements
• Changes Carry Risk

4
Circuitry

• Shield between DOMMB and delay for PS noise-
  Reduce EMI pick-up
• Shield over 7W DC-DC converter- Reduce EMI
  pick-up
• Add Bypass capacitors at ATWD for PS noise-
  Filter noise
• Add 1.8V SDRAM Memory Power Option- One 0603
  Jumper Footprint
• Add enhancement for LC Tx Idle Restoration- Two
  0603 Resistor Footprints Traces

5
Design for Manufacturability for Integration

• Move/Modify Signal Connections- Twisted Pair
  Attachments Become Posts- Relocate RA SMB PMT
  Signal Connector
• DNL (do not load) TP25- Resolve Interference
  with RA SMB
• 0.005 trace/space feasibility- Toward Full
  IPC 6012 Class 3 Compliance
• Serial number relocation- Enable inspection for
  sealed DOM

6
Reliability Related

• Delete (?) Panasonic CM Inductor
• Eliminate Capacitors with Pure Tin Leads- by
  Footprint Changes, 0603 ? 0805
• Miscellaneous
• No-Load hard and soft reboot push buttons
• Various loading clarifications in schematic

7
Remaining Issues

• Communications Balun(s)
• Shielding/Moving DC-DC Converter to Suppress EMI
  consistently below ¼ SPE
• Timely Delivery of Corning Oscillators
• Tin on Corning Oscillator Components
• Undiscovered Integration Issues

8
Conclusion

• Significant progress in the last year.
• Converging (or converged?)
• The performance is there.
• Small worries remain