1. GLAST Large Area Telescope GLAST Large Area Telescope
Gamma-ray Large Area Space Telescope
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

2. 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
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.

3. LVP159/LPS598 – DC Voltage Tolerance
Analysis Report/Test Report Doc #(s):
CCR # 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 paragraph
Crate Power Supply, LAT-DS-02390
The test procedure for the Crate Power Supply is LAT-TD_01673 paragraph
GASU Power Supply, LAT-DS-02413
The test procedure for the GASU/ACD Power Supply is LAT-TD_01727 paragraph
The PDU 40 volt compliance is by analysis.
The PDU Assembly schematic diagram is LAT-DS
The PDU CCA schematic is LAT-DS
LAT-DS 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.
A DC-DC converter, MAX-724, rated at maximum of 45 volts
Two power FETs are used to switch spacecraft power to loads are rated at 60V
All wire used is MIL-W rated at 600V

4. LVP159/LPS598 – DC Voltage Tolerance
Compliance Statement: LAT Complies
NCRs/JIRAs: None