UCC21222: UCC21222QDQ1 IC technology

Hi,

Thanks for your reply.

In the derating Tool, What does qualification temperature mean? What value should i mention?

What is the DPPM for this part: UCC21222QDQ1? Where does this value come from, when base FIT is given for zero failures. Should this value be in millions when FIT is given for 10^9 hours?

Thanks,

Suresh.

Hi John,

Thanks for your reply!

Could you please clarify below points.

1) I just tried to check the application FIT for UCC21222QDQ1 at 55degC in the de-rating tool (refer belwo image). I dont know the DPPM value. So derived from sample sizes and failures mentioned in link below.

I am getting 0.2 FIT for 0.7eV which is lower than the base FIT value given in link below.

https://www.ti.com/quality/docs/estimator.tsp?OPN=UCC21222QDQ1&CPN=&partNumber=ucc21222#resultstable

Could you please clarify how this DPPM value is derived? What values should i use for sample size? and no of failures?  Is this a kind of estimated field failure data we need to use based on past experience??

2) Also, here only temperature is considered for de-rating the FIT value.

I am using MIL-HDBK-217E std for deriving the application FIT from the Base FIT given by TI. In that, i am considering below factors for UCC21222QDQ1 to calculate the application FIT from the base FIT.

Screening factor

temperature factor

Packaging factor

Family Factor (MOS,BJT.,)

Please clarify whether i can use MIL standard (as described above) to calculate application FIT for TI parts or, i should refer to only JEDEC test standard and derating tool?

Thank you for your support.

Regards,

Suresh

Hi Suresh,

For point 1, I have reached out to our quality team to check on this question and will update you by end of Wednesday.

For point 2, can you please clarify the application for UCC21222-Q1? Is this to support functional safety assessment for an automotive application, or is it something else. We do not typically see MIL standards used for automotive applications. Do you have a mission profile? This might help me with communication in our internal teams.

Thanks and best regards,

John

Hi John,

Yes.UCC21222QDQ1 is used for automotive application only, for BSG (Belt starter generator) with functional safety requirement of ASIL B. MIL standard is part of customer requirement. 

Regards,

Suresh

Hi John,

I dont have a mission profile at present. Only having the product life time for which iam checking whether it meets. 

Regards,

Suresh

Hi Suresh,

We typically see our other customers use the Siemens or IEC standards for calculating FIT for functional safety. I've reached out to another internal team and I am waiting on a response from them. I will try to follow up on this post by Friday. 

For your questions on the TI.com tools, please see response from our expert below:

---

-          We use HTOL de-rating with a combination of Chi-squared model for our FIT estimations.
I cannot comment too much on MIL-HDBK-217E it seems they use some type of transistor count based estimation with some additional factors, which seems outdated and is not our approach.

• Please note that our estimator is based solely on technology grouping (which is composed of data all devices in the same technology group) and is not specific to any device:
  TI.com page: “TI’s DPPM/FIT/MTBF estimator search tool allows you to find generic data based on technology groupings to estimate these typical questions and shows conditions under which the rates were derived.”

-          DPPM is derived using the Chi-squared fail estimation method (used in zero-fail circumstances). Sample size is can be found on estimator page for the product.

• Also caution must be exercised when using the Temperature change FIT page, this page is not compatible for devices that are in multi-chip module (MCM) format. We are investigating updating the calculator to make it compatible, but for now it only shows results for single die devices.

---

Thanks,

John

Hi,

In SAE 870050, asks for screening factor (refer below) for IC for calculating the FIT. Can i get those those details for ucc21222.

Screening Factors:

1) Electrical and Environmental

2) Electrical

3) No screening

Can anyone tell what this screening factor means?

 

Regards,

Suresh.

 

 

Hello Suresh,

I work with John in the High Power Drivers group. 

He is currently out of office so I want to make sure that we've addressed your questions.

Do you have any additional gate drivers applications related questions? If so, please further post on this thread. 

Regards,

-Mamadou

Hi,

I am working on the reliability analysis for BSG project, and getting some queries regarding the Component FIT values. It would be great if you could support for some of the queries I come across.

In the FIT report,  I see the Junction temperature is 55degC and Test temperature Can you tell how you maintain the Junction temperature at 55degC when test temperature is 125degC?

Thanks & Regards,

Suresh.

Hi, Suresh,

The FIT report is based on 55C junction temperature during operation. 125C is the temperature we use for our acceleration factor. So, they are not being applied at the same time.

Hi Don,

Thanks for your reply. Could you please let me know what is the use temperature (i.e., ambient for 55C junction temperature) i should consider?

Thanks & Regards,

Suresh

Hi Don,

Could you also comment on the screening factor for part no:  UCC21222QDQ1

Which one it belongs to from the below:

1) Electrical and Environmental

2) Electrical

3) No Screening

Thanks & Regards,

Suresh.

Hi Suresh,

My colleague will be reaching out to you via email to answer this question for you.

Suresh R said:

Hi Don,

Thanks for your reply. Could you please let me know what is the use temperature (i.e., ambient for 55C junction temperature) i should consider?

Thanks & Regards,

Suresh

Hi Don,

Can you answer for above question?

Regards,

Suresh.

Hi, Suresh, The junction temperature will depend on the conditions you are using the part under. For example, load, gate resistor, switching frequency, etc. Let’s move this conversation to email for further questions. I believe my colleague has already reached out to you.