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Junction-to-case thermal resistance data (Rjc) for various parts

Other Parts Discussed in Thread: CSD18541F5, SN74LVC138A, SN74LV393A

Please provide junction-to-case thermal resistance data (Rjc) for the following parts to assist with thermal modelling:

1 CD74HC4067SM96
2 CSD18541F5T
3 LMK1D1204RGTT
4 SN74LVC2G74MDCUTEP
5 SN74LVC138AQDREP
6 SN74LV393ATPWREP
  • Hi Kiran,

    We will have to submit thermal requests for these devices. The turn around time will be around 2 weeks.

    I will respond back on this when we have the thermal information back. 

  • Hi Kiran,

    I will assign this to MUX for now while I wait for the thermals to come back for SN74LVC138AQDREP and SN74LV393ATPWREP.

    For now, I have SN74LVC2G74MDCUTEP thermals below. 

    SN74LVC2G74MDCUTEP Thermals:

    Result- Theta JA-High K (standard datasheet value) 199.5
    Result-Theta JC, top (standard datasheet value) 74.6
    Result-Theta JB (standard datasheet value) 78.2
    Result- Psi JT (standard datasheet value) 6.3
    Result- Psi JB (standard datasheet value) 77.8
    Result-Theta JC, bottom (standard datasheet value)

    n/a

  • Hi Kiran,

    See below for info on CD74HC4067SM96. Kicking over to HVP-FET now. 

    Result- Theta JA-High K (standard datasheet value) 74.2
    Result-Theta JC, top (standard datasheet value) 33.4
    Result-Theta JB (standard datasheet value) 32.5
    Result- Psi JT (standard datasheet value) 5
    Result- Psi JB (standard datasheet value) 32.1
    Result-Theta JC, bottom (standard datasheet value) N/A N/A

    Thanks!

    Alex

  • Hello Kiran,

    Thanks again for your interest in TI FETs. The CSD18541F5T is a chip scale device. Essentially, a silicon chip with solderable, metallized LGA pads. There is no lead frame, bond wires or plastic overmolding. Therefore, we do not spec Rθjc in datasheet since case and junction are very nearly the same temperature. There should be very little difference in temperature measured on the surface of the device and the junction temperature. Please let me know if you have any additional questions. FYI, the CSD18541F5T and CSD18541F5 are the same device with the only difference being reel size and quantity per reel. The CSD18541F5T is in a small reel with 250 pieces per reel and the CSD18541F5 is in a large reel with 3000 pieces per reel.

    Thanks,

    John

  • Thanks for your responses. I am still waiting for thermal data for

    SN74LVC138AQDREP,
    SN74LV393ATPWREP and
    LMK1D1204RGTT

    Appreciate your response as soon as possible.

  • Thanks for your responses. I am still waiting for thermal data for

    SN74LVC138AQDREP,
    SN74LV393ATPWREP and
    LMK1D1204RGTT

    Appreciate your response as soon as possible.

  • Hi Kiran,

    Regarding: SN74LVC138AQDREP, SN74LV393ATPWREP

    I just checked and it has not been updated yet, but in work. 2 weeks is on this Thurday, 7/20, so I will check back then. Generally the thermal information comes back exactly on time.

  • Hi Kiran, 

    SN74LVC138A:

    Result- Theta JA-High K (standard datasheet value) 92.3
    Result-Theta JC, top (standard datasheet value) 53.3
    Result-Theta JB (standard datasheet value) 50.6
    Result- Psi JT (standard datasheet value) 16.6
    Result- Psi JB (standard datasheet value) 50.3
    Result-Theta JC, bottom (standard datasheet value) n/a

    SN74LV393A:

    Result- Theta JA-High K (standard datasheet value) 124.3
    Result-Theta JC, top (standard datasheet value) 52.2
    Result-Theta JB (standard datasheet value) 67.5
    Result- Psi JT (standard datasheet value) 7.4
    Result- Psi JB (standard datasheet value) 66.9
    Result-Theta JC, bottom (standard datasheet value) n/a
  • Thanks

    Only one more left now (LMK1D1204RGTT). Will someone be looking into this?

    Regards

    Kiran

  • Hi Kiran,

    Below are values for LMK1D1204RGTT.

    Result- Theta JA-High K (standard datasheet value) 48.7
    Result-Theta JC, top (standard datasheet value) 56.4
    Result-Theta JB (standard datasheet value) 23.6
    Result- Psi JT (standard datasheet value) 1.6
    Result- Psi JB (standard datasheet value) 23.6
    Result-Theta JC, bottom (standard datasheet value) 8.6

    Best,

    Asim