FXO-LC52 Datasheet, PDF (14/15 Pages) Fox Electronics – LVDS 5 x 3.2mm 2.5V Oscillator

FXO-LC52 Series
MTTF / FITS Calculations
Products are grouped together by process for MTTF calculations.
(All XpressO output and package types are manufactured with the same process)
Number of Parts Tested: 360 (120 of each output type: HCMOS, LVDS, LVPECL)
Number of Failures: 0
Test Temperature: 125°C
Number of Hours: 2000
MTTF was calculated using the following formulas:
[1.] Device Hours (devhrs) = (number of devices) x (hours at elevated temperature in °K)
[2.]
MTTF
=
devhrs × af
χ²
×2
[3.] FITS =
Where:
Label
1
* 10⁹
MTTF
Name
af
Acceleration Factor
eV
Activation Energy
k
Bolzman’s Constant
Formula/Value
e( eV )×( 1 − 1 )
k t₁ t₂
0.40 V
8.62 X 10^-5 eV/°K
t₁
t₂
Θ
Theta
Operating Temperature (°K)
Accelerated Temperature (°K)
Confidence Level (60% industry standard)
r
Failures
χ²
Chi-Square
Number of failed devices
statistical significance for bivariate tabular analysis [table look-
up] based on assumed Θ (Theta – confidence) and number of
failures (r) For zero failures (60% Confidence): χ² = 1.830
DEVICE-HOURS = 360 x 2000 HOURS = 720,000
e ^{ACCELERATION FACTOR =}
( ^0.40 )×( ¹ − ¹ )
8.625 298 398 _{= 49.91009}
MTTF = ^{720,000 × 49.91009 × 2} = 39,209,238 Hours
1.833
Failure Rate =
1.833
= 2.55E-8
720,000 × 49.91009 × 2
FITS = Failure Rate *1E9 = 26
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