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TLV766-Q1: Thermal resistance compared with TLV767-Q1

Scarlett Cao
Expert 4160 points
Part Number: TLV766-Q1
Other Parts Discussed in Thread: TLV767-Q1, , TPS7B86-Q1

Hi team,

Customer is choosing LDO for transmission control unit and has high ambient temperature VIN=14V,VOUT=5V,Iout=150mA；(Ta=115℃);

 I'm promoting TLV766-Q1 but customer think the thermal resistance is too large, when I check TLV767-Q1 I found the thermal information chart is exactly the same. I don't understand why a 1A rating LDO has the same thermal performance with it's p2p 0.5A version? Previously I though larger curretn rating LDO should have smaller thermal resistance. If not, how can it support larger load current?

Thank you

Scarlett

  • 0
    TI__Mastermind 18466 points

    Hey Scarlett, 

    I have messaged the marketing team recommended TPS7B86-Q1, if it works for your application. 

    The two LDOs [-77 and -67] are on a similar process flow and have a similar die size. From our thermal modelling team:

    "Rja only depend on physical dimensions and material property.  Not current."

    Current rating has an effect on power dissipation.

    However, how you layout the board is critical to thermal metrics. On some of out newer datasheets we are including the thermal metrics seen on our EVMs compared to thermal metrics using the JEDEC standard; sometimes we see an improvement of a 50% decrease on the Theta-ja value. 

    We have this white paper that goes into greater detail: An empirical analysis of the impact of board layout on LDO thermal performance

    Examples of datasheet with EVM thermals included: TPS7A94 

    Best,

    Juliette