The prediction of the steady-state failure rate for a device is based on a generic steady-state failure rate for the type of device per Telcordia Technologies Special Report SR-332 Issue 3. This generic value is then modified for quality, stress, and temperature. The mean black box steady-state failure rate, λBBi , is:

λBBi = λGiπQiπSiπTi

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Where:

λGi = Mean generic steady-state failure rate for device i (Section 8).   

πQi = 1.0; Quality Factor for device i (Section 9.3).

πSi =
 1.0; Electrical Stress Factor for device i (Section 9.2) based on the percent electrical stress.

If stress is unknown, use 1, which assumes 50% electrical stress.

πTi = 2.0; Temperature Factor for device i at 85°C; Ea = 0.15eV (Section 9.1).

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Hall-Effect Current Sensors Steady-State FITs (Failures/Billion Hours) MTBF* (Hours)
ISB Series (Connector/Lead-Wire) 94.2 10,618,736
ISC Series (Connector/Lead-Wire) 94.2 10,618,736
ISE Series (PCB Mounting) 94.2 10,618,736
Magnetic Components Steady-State FITs (Failures/Billion Hours) MTBF* (Hours)
Gate Drive Transformers (GT and XT Series) 19.7 50,731,486
Current Sense Transformers (CT Series) 6.0 165,722,855
Fixed Inductors (Class D and High Current Power Inductors) 1.8 552,409,518
High Current Inductors (LP Series and Non-Standard Inductors) 1.8 552,409,518
  • MTBF: Calculated from FITs (MTBF=10^9 (hours) / FITs)
  • Hall-Effect Current Sensors FITs : πTi = 1.0; @ 40°C; (Section 9.1)
  • Magnetic Components FITs : πTi= 2.0; @ 85°C; Ea = 0.15eV