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LMT87: What was the VDD value used to create the data in Table 3 ("LMT87 Transfer Table") in LMT87.pdf ?

Part Number: LMT87

Hello everyone,

What was the VDD value used to create the data in Table 3 ("LMT87 Transfer Table") in LMT87.pdf?

I do not see the value of VDD used to create the data in Table 3 ("LMT87 Transfer Table") in https://www.ti.com/lit/ds/symlink/lmt87.pdf.

Does anyone know what that value of VDD is or where I can find it? 

Thank you!

joe.flowers@nofreewill.com

LMT87LPG (TO-92S package)

  • Hi Joe,

    The supply voltage is irrelevant, because the output is absolute. The LMT87 should ideally output 2298mV at 25C regardless of supply voltage.

    thanks,

    ren

  • "The supply voltage is irrelevant"

    Sigh. If this were true, then Figure 9 would be flat, and VDD would not show up in equation (7).

  • Table 3 describes intended operation of the device, and is already quite verbose in its description. The output is also described by a function.

    When I look at Figure 9, I see the minimum supply voltage needed to operate the device. Any behavior in the operating range on the right side of the chart is defined by the Line Regulation spec in the EC table. You should apply the Line Regulation spec to the output function to estimate worst case variation, if that is your wish.

    Equation 7 defines thermal dissipation, and wouldn't seem to be related to the output voltage discussion at hand. At least, it is only indirectly related in the sense that a temperature sensor should indicate it's temperature. Vout and VDD are used here to estimate power; it's not used to estimate the indirect impact on Vout.

    thanks,

    ren

  • I do not have time to keep wasting on a strawman argument and a hijacked thread. I asked a question: 

    What was the VDD value used to create the data in Table 3 ("LMT87 Transfer Table") in LMT87.pdf?

    I do not care about any "answers" to any other questions. The unit of the acceptable answer is Volts, along with the reference.

  • Dear Joseph - 

    Thanks for the comments - as was responded previously  - the answer here is what you find in Figures 7 and 9. These directly represent the characterization data, where the output data was taken at 2.7VDC, 3.5VDC. 5VDC and 5.5VDC to produce those graphs.