How TI calculate MTBF?

Andrey Karutin

Other Parts Discussed in Thread: TPS763

First i use TI information about MTBF for

	MTBF	FIT	lambda	T	P
TXB0108PWR	966100000	1,03509	1,04E-09	30000	0,999969
TPS76301DBVT	2,46E+09	0,406504	4,07E-10	30000	0,999988
SN65LVDT33PW	349000000	2,86533	2,87E-09	30000	0,999914

where T - time in hours, P - faultness probability.

But then i used MIL-HDBK-217F2 for this elements

	Temp C	C1	Еа	Nt	P	θjc	Tj
TXB0108PWR	40	0,02	0,65	298	0,001	10	40,01
TPS76301DBVT	40	0,01	0,65	298	0,3	20	46
SN65LVDT33PW	40	0,01	0,65	298	0,0759	10	40,759

P_t	N	C2	P_e	P_q	lambda	T	P
0,336641	14	0,006225	0,5	10	9,85E-08	30000	0,997051
0,529288	5	0,002047	0,5	10	6,32E-08	30000	0,998107
0,356575	16	0,00719	0,5	10	7,16E-08	30000	0,997854

and my results worse that TI.

Can smbd tell me where is my mistake?

over 12 years ago

0 Texas Instruments2 over 12 years ago

TI__Intellectual 2350 points

Hi Andrey,

What technology, or product line, are you using this for? It will help me place your question into the correct forum so it will be answered more quickly.

0 Andrey Karutin over 12 years ago in reply to Texas Instruments2

Prodigy 30 points

Justin,

i use it to find MTBF of my device, tps76301 - for DAC powering, txb and sn65lvdt - at the input. Whole device is a part of high speed transmitter.

0 Texas Instruments2 over 12 years ago in reply to Andrey Karutin

TI__Intellectual 2350 points

Thanks Andrey.

0 Darwin Fernandez over 12 years ago in reply to Texas Instruments2

TI__Mastermind 40720 points

Aubrey,

The reliability data on the web is commercial data, not military. This is also stated on page 25 of the TPS763 datasheet. TI follows standard Jedec calculations for MTBF/FIT which may not follow the standards of MIL-HBK-217 and therefore is not a direct correlation.

Regards,

Darwin

0 Andrey Karutin over 12 years ago in reply to Darwin Fernandez

Prodigy 30 points

Darvin,

i am making not military device, i just want create reliable product and in mil-hnbk-217 there is also technique for ground use.

what exacly JEDEC standard TI use?

0 Darwin Fernandez over 12 years ago in reply to Andrey Karutin

TI__Mastermind 40720 points

Hi Audrey,

Searching for the JEDEC standards and MTBF yields the following results.

http://www.jedec.org/standards-documents/dictionary/terms/mean-time-between-failures-mtbf

You might have to register to view the documents. You may want to compare your end results with the reliability information shown in the product page.

Regards,

Darwin

Power management

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How TI calculate MTBF?