Three LM1117T-3.3 and two LM2931 low-voltage dropout (LVDO) linear regulators were tested with protons. The intent of the test was to do an intial evaluation of these devices, not a comprehansive qualification run. All tests were performed at room temperature and annealling effects were not looked at. Input voltage for all runs was +5 VDC and the proton energy was 63 MeV. No significant changes in input current or output voltage were detected. Data on dropout voltage is not available.
The DUT test card can be seen at: Regulator_3volt.PDF
The following table summarizes these test runs:
| Device | DUT S/N | IIN Initial |
IIN Final |
VOut Initial |
VOut Final |
Dose krad (Si) |
| LM2931CT | 1 | 48.9 | 50.1 | 3.18 | 3.19 | 50 |
| LM2931CT | 2 | 48.9 | 50.9 | 3.18 | 3.20 | 100 |
| LM2931CT | 3 | 49.5 | 51.1 | 3.21 | 3.17 | 150 |
| LM1117T | 1 | 54.9 | 55.1 | 3.31 | 3.32 | 150 |
| LM1117T | 2 | 55.1 | 55.1 | 3.31 | 3.32 | 150 |
Acknowledgements: Testing conduction and data reduction courtesy of Dr. Robert Reed, NASA Goddard Space Flight Center.
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Last Revised: January 09, 2002
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