Non-operating time in Mission profile

[kiminkim]

Hello, team

I have a general question about our mission profile in terms of all devices like MCU, MMIC and PMIC.

Where can I find the mission profile of the non-operating time(e.g. 119,400h) especially in the view point of temperature?

If I refer to the mission profile sheet in "FailureRateBasis_IEC_TR62380_S32R27R_rev_1_0.xlsx", we don't see this kind of information.

BR

Justin

[nxf64307]

Hello Justin,

In the same sheet(Mission Profile), Ton and Toff time is mentioned in Col ‘AJ’ and Col ‘AK’ respectively. This is mentioned in terms of % to Tlifetime. The mission profile is provided depending on application type which lists temperature factor for varied range of ambient temperature per working time ratio. This working time is summed in col ‘AJ’ and used to calculate non-operating time in col ‘AK’.

For eg. If expected lifetime is 15years and Toff is calculated as 90.8% then the non-operating time= 15*365*24*0.908 which will come nearly 119,300h.

Regards,

Rupesh

[kiminkim]

Hello, Rupesh

Thanks for your kind response.

May I ask a few following questions?

Q1. Who can decide and enter Life Time in Mission profile sheet? For example, we have 10 years as a default in "FailureRateBasis_IEC_TR62380_S32R27R_rev_1_0.xlsx".

Q2. User can alter the data in "User mission profile III" and User mission profile V" both. Is it correct? If so, can we just leave as a default in "Thermal Cycles N" if user doesn't have specific data?

BR

Justin

[nxf64307]

Hello Justin,

I would also like to elaborate on Q2 for the second on half i.e.,

If so, can we just leave as a default in "Thermal Cycles N" if user doesn't have specific data?

Ans. Yes, if the customer has not provided specific Thermal Cycle then we can calculate the failure rate using the mission profile with standard thermal cycle phases mentioned in IEC TR 62380.  

Phase 1: 2 night starts;

Phase 2: 4 day light starts.

Phase 3: Non-used vehicle, dormant mode 30 days per year.

Regards,

Rupesh

[kiminkim]

Hello, Rupesh

Thanks for your kind explanation.

Now I understand well.

Let me close this case.

BR

Justin

[nxf64307 · Accepted solution]

Hello Justin,

Please find my answers below:

Q1. Who can decide and enter Life Time in Mission profile sheet? For example, we have 10 years as a default in "FailureRateBasis_IEC_TR62380_S32R27R_rev_1_0.xlsx".

Ans. The Lifetime of the device is based on mission profile supported based on qualification of device. Quality Team must be contacted to find the lifetime supported for the device.

Q2. User can alter the data in "User mission profile III" and User mission profile V" both. Is it correct? If so, can we just leave as a default in "Thermal Cycles N" if user doesn't have specific data?

Ans. Yes, the mission profile can be selectable by User. It will depend on the placement of the Item under development, suppose if the item is placed under the trunk then the ambient temperature profile will be different as compared to the item placed near the engine where the item will be exposed to higher temperature for longer time during the operation of the vehicle. Hence, this effects the failure rate of our IC. Therefore, it is an selectable feature under ‘Integrated Circuits’ sheet on Cell ‘B10’ which can be suitably selected depending on the placement of the Item in vehicle.

I hope this helps.

Regards,

Rupesh