FVXO-PC72 Series

Page 14 of 15

© 2008 FOX ELECTRONICS | ISO9001:2000 Certified

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.]

2

2

χ

×

×

=

af

devhrs

MTTF

[3.] FITS =

MTTF

1

* 10

9

Where:

Label

Name

Formula/Value

af

Acceleration Factor

e

t

t

k

eV

)

1

1

(

)

(

2

1

−

×

eV

Activation Energy

0.40 V

k

Bolzman’s Constant

8.62 X 10

Operating Temperature (°K)

Accelerated Temperature (°K)

Θ

Theta

Confidence Level (60% industry standard)

r

Failures

Number of failed devices

χ

2

Chi-Square

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):

χ

DEVICE-HOURS = 360 x 2000 HOURS = 720,000

ACCELERATION FACTOR =

e

)

398

1

298

1

(

)

625

.

8

40

.

0

(

−

×

= 49.91009

MTTF =

833

.

1

2

91009

.

49

000

,

720

×

×

= 39,209,238 Hours

Failure Rate =

2

91009

.

49

000

,

720

833

.

1

×

×

= 2.55E-8

FITS = Failure Rate *1E9 = 26

MTTF / FITS Calculations