Coilcraft Failure Rate (FIT) Calculation
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Failure Rate Calculation

FIT View PDF data sheet

The steady-state FITs is calculated = λGπQπSπT (failures / billion hours) per Telcordia Technologies Special Report SR-332, Issue 1, May 2001.

λG = chosen from Telcordia SR-332, Table 7-1 (90% upper confidence level)
πQ = 1.0 (from from Telcordia SR-332, Table 7-4 for Quality Level II)
πS = 1.0 (from from Telcordia SR-332, Table 7-6, assuming 50% electrical stress level)
πT = 2.0 (calculated for +85°C per Table 7-7 with Ea activation energy = 0.15 eV)

Steady state FITs
(failures/billion hours)
RF Magnetics
Chip inductors (all sizes) 1.0 1,000,000,000
Air core "Spring" inductors (all sizes) 1.0 1,000,000,000
90 Series axial lead inductors 1.0 1,000,000,000
RFID transponder coils 1.0 1,000,000,000
Tunable inductors (Unicoils, Slot Series) 2.0 500,000,000
Conical broadband inductors 38 26,315,789
Wideband RF transformers, chip transformers, baluns, directional couplers 60 16,666,667
Power Magnetics
Power chip inductors (PS, FS – all sizes) 38 26,315,789
SMT inductors (DH, DO, DS, DT, EPL, LPD, LPO, LPS, ME, MLC,
38 26,315,789
Coupled power inductors (LPD, MSD, PFD) 38 26,315,789
Fixed inductors (PCH, PCV, DMT, Mag Amps, etc.) 38 26,315,789
Transformers (including base/gate drive, power factor controller, planar
and CCFL)
38 26,315,789
Current sensors 38 26,315,789
EMI Magnetics and LC Filters
Filter coils (including PDLF, PTRF, CCDLF, TTDLF, DLF) 38 26,315,789
Common mode chokes (including DLF, PDLF, CCDLF, TTDLF, TRF,
PTRF, TTTRF, P32xx, BU, USB Series)
38 26,315,789
Filtered connectors (including TRFRJ, PCRJ) 38 26,315,789
Filter assemblies (including PxLP and SxxP) 12 83,333,333
xDSL Magnetics
xDSL transformers 38 26,315,789

* Calculated from FITs (MTBF=109 (hours) / FITs)

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Updated: April 16, 2018