LM61460-Q1: FIT/MTBF information between safety document and FIT estimator

Roy Chou1

Genius 13525 points

Part Number: LM61460-Q1

Hi Team,

As title, I used below website to get FIT.

https://www.ti.com/quality/docs/estimator.tsp?partType=tiPartNumber&partNumber=LM61460AANQRJRRQ1#resultstable

It's different from functional safety document. May you let me know your idea?

https://www.ti.com/lit/fs/snva920b/snva920b.pdf?ts=1668089401292&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FLM61460-Q1

Also, may you share when will we use MTBF information? Thank you.

Regards,

Roy

Regards,

Roy

over 1 year ago

0 Jimmy Hua over 1 year ago

TI__Guru 50120 points

Hi Roy,

Let me look into this and get back to you after I get more details from the systems team.

Regards,

Jimmy

0 Jimmy Hua over 1 year ago in reply to Jimmy Hua

TI__Guru 50120 points

Hi Roy,

I just got further explanation of the difference in the MTBF/FIT estimator and the actual functional safety information document.

I quote , " The MTBF/FIT calculator open to the customers shows the typical “Bath Tub” device mortality which is based on reliability data and customer returns. For functional safety purposes the FIT rate that needs to be used has to come from standards such as IEC62380 and SN29500. These calculate FIT rates based on transistor count, package size, power dissipation."

Regards,

Jimmy

0 Roy Chou1 over 1 year ago in reply to Jimmy Hua

TI__Genius 13525 points

Hi Jimmy,

Thank you for your information.

Can I say if we want to calculate the system total FIT to meet ASIL level, we may follow ISO26262 standard. So I need to use LM614xx-Q1 Functional Safety, FIT Rate, Failure Mode Distribution and Pin FMA (Rev. B)

May you share the scenario that we can use MTBF/FIT calculator?

Regards,

Roy

0 Jimmy Hua over 1 year ago in reply to Roy Chou1

TI__Guru 50120 points

Hi Roy,

I think the customer can use the MTFB results since it is based on reliability data and customer returns to get a understanding of the susceptibility of the device. However when talking about FIT rate values, it must follow the standards as previously mentioned so customer should simply reference the functional safety document for all questions related to that.

Regards,

Jimmy

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LM61460-Q1: FIT/MTBF information between safety document and FIT estimator