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TPS745-Q1: life span estimation

Elec Cheng
Expert 7055 points
Part Number: TPS745-Q1

Hi Expert,

Please help to estimate TPS74501-Q1 life span with below working condition. The OEM requires 15years /300k km life span. Please help evaluate if we can meet this requirement. Thanks.

ITEM

TIME(HOUR)

Engine on

8000

Charging

13350

Self-checking

3000

Total Lifetime

24350

Temperature(℃)

Distribution(%)

Engine on

Charging

Self-Checking

-40

6

6

6

23

20

64

64

42

65

25

25

80

8

4

4

85

1

1

1

 BR,

Elec Cheng

  • 0
    TI__Genius 13085 points

    Hey Elec Cheng, 

    If what the customer has provided is the junction temperature (Tj=Ta+Rja*Pd) then the answer is yes it will support this mission profile. 

    If what the customer provided was the ambient temperature, then they will need to estimate thee junction temperature. It may support this mission profile depending on the power dissipation (Pd) and what package they choose since the thermal resistance (Rja) will depend on which package.

    I've attached the worksheet that can be used to assess this for each package, all they need to do is enter their power dissipation (I've entered the maximum we can support assuming their board dissipates heat at least as wellto the JEDEC High-K board which is used for the Rja values in our datasheets). If they make changes to the values to better align with their use case (power dissipation, thermal resistance, etc...) then make sure that cell L10 is still green, if L10 is red then the mission profile and conditions are not supported. 

    We have an App Note which shows how the thermal dissipation (θja) can be affected by board layout and it shows that with an optimized PCB layout the Rja listed in our datasheets can be reduced by 35%-55%. https://www.ti.com/lit/an/slvae85/slvae85.pdf

    Mission Profile vs AECQ100 Grade 1 HTOL.xlsx