DC-DC converter R

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DC-DC converter RD US ATLAS Upgrade

• UCSC
• May 2007

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Credits

• FY07 P. Denes, R. P. Ely, M. Garcia-Sciveres, M.
  Gilchriese, J. Alonso.
• FY08 same.

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Progress in FY07

• Irradiation of FY06 test chip at LBNL 88
  cyclotron
• Design and submission of new realistic size test
  chip
• Multi-project run submission in Feb.
• Chips have been already received April 17, 2007.
• Initial basic testing with probes in progress
• PCB test board in fabrication
• If test boards results as expected, produce strip
  stave compatible power card that can be used in
  place of serial power adapter.

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Top level schematic
Charge to gate drivers
Clock inputs (same freq. with varying delays)
1mF pump capacitors
These components could be internal eventually
Load
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Simulation results 1
Charge lost in switch parasitics
Dominated by switch resistance
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Simulation results 2
Startup circuit
1MHz, 1mF pump caps
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Plans for FY08

• Collaborate with CERN for testing and irradiation
  of FY07 test chip
• In 2006/7 CERN has started an aggressive DC-DC
  RD program already funded at the 1.5 FTE level
• gt300K additional Europe-only funding for DC-DC
  is being sought by CERN in the form of an FP7_CNI
  proposal to be submitted in May 07.
• CERN IC group now working on a switching chip for
  an inductive converter along similar lines as the
  LBNL DC-DC work (with a different foundry)
• They Plan to explore piezo-electric converter
  options as well and establish a test program to
  compare all 3 approaches (inductive, capacitive,
  piezo).
• They have X-ray irradiation equipment for total
  ionizing dose characterization.
• Work on design and submit next version of
  switched capacitor DC-DC chip
• Aim of this next chip would be miniaturization
  for production of a stand-alone device.
• Main challenges of miniaturization
• Reduction of external components
• Control circuitry to internally produce required
  switching signals

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FY09

• Depends on success of FY08 effort
• To be conservative assume a new chip iteration
• An important possibility if FY07 and F708 chips
  are successful is to shift to improving radiation
  hardness, which may require migrating working
  design to a different switch technology
• Complete miniaturization work by producing a
  ceramic hybrid to achieve the smallest possible
  package
• Produce parts that can be used like off the
  shelf components

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DC-DC Cost breakdown FY08-09