GLAST Large Area Telescope

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GLAST Large Area Telescope
GLAST Large Area Telescope
LAT Level Requirement Sell-off Package
for LVP159/LPS598 DC Voltage
Tolerance Requirement Owner David
Nelson Approval Date Approved By LAT Docs
No LAT-MD-08398
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LVP159/LPS598 DC Voltage Tolerance

• Requirement
• The LAT shall tolerate without damage or
  degradation DC voltages greater than 15.0 volts
  and less than 40.0 volts.
• Verification Method A5
• Verification Plan
• 1) This requirement has a waiver submitted to
  NASA. This analysis sets the minimum voltage to
  18.5 volts. The CCR number is 433-0357.
• 2) Analysis will show that all of the components
  are rated for 40 volt operation.
• Test Script Run Info
• Worst Case Measured Data N/A
• Margin N/A
• Test/Analysis Summary Analysis shows that the
  minimum voltage is 18.5 volts. All subsystem
  assemblies are rated to 40 volts.

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LVP159/LPS598 DC Voltage Tolerance

• Analysis Report/Test Report Doc (s)
• CCR 433-0357 is the analysis for 18.5 volt
  operation.
• The 40 volt operation was successfully tested on
  each of the following subassemblies
• Tower Power Supply, LAT-DS-01482
• The test procedure for the Tower Power Supply is
  LAT-TD-01652 paragraph 5.5.2-6
• Crate Power Supply, LAT-DS-02390
• The test procedure for the Crate Power Supply is
  LAT-TD_01673 paragraph 5.4.1-35
• GASU Power Supply, LAT-DS-02413
• The test procedure for the GASU/ACD Power Supply
  is LAT-TD_01727 paragraph 5.4.1-36
• The PDU 40 volt compliance is by analysis.
• The PDU Assembly schematic diagram is
  LAT-DS-01696.
• The PDU CCA schematic is LAT-DS-02127.
• LAT-DS-02127 sheet 6 of 66, PDU_3_3_V_PS is the
  schematic of the 28V to 3.3V power converter.
• There is a series of capacitors, C42-C47 C49
  which is rated at 50V
• An input filter, ARF461 which is rated at 80
  volts.
• http//www.irf.com/product-info/datasheets/hirel/a
  rf461.pdf
• A DC-DC converter, MAX-724, rated at maximum of
  45 volts
• http//pdfserv.maxim-ic.com/en/ds/MAX724-MAX726.pd
  f

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LVP159/LPS598 DC Voltage Tolerance

• Compliance Statement LAT Complies
• NCRs/JIRAs None