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LP38693: Ven for Vin = 5V

Part Number: LP38693

Hi Team,

In the figure in the post below, there seems to be a relatively linear relationship between Vin and Ven:

https://e2e.ti.com/support/power-management/f/196/p/632570/2334128?tisearch=e2e-quicksearch&keymatch=lp38693%20enable#2334128

However, this same linearity does not seem to apply to the Electrical Characteristics section that describes the Ven threshold voltage at 4V and 6V when temperature and process variation are taken into consideration. 

I am ultimately seeking to understand what the Ven threshold votlage should be across temperature and process variation for Vin = 5V, but I cannot extract this information reasonably from the datasheet. Would it be possible to provide a minimum specification for Ven when Vin =5V? 

Thank you,

Jared

  • Hi Jared,

    The previous post shows the typical characteristics for how Ven changes with Vin. As you note, this is a linear relationship. While the Electrical Characteristics Table limits are not perfectly linear should you plot the 3, R^2 for a linear regression is 0.9423 and the trend is still the same with the limits rising with Vin. As such providing a minimum of 3 V for Ven will ensure that the regulator is enabled for an Vin 6 V and lower.

    Very Respectfully,
    Ryan
  • Hi Ryan,

    While I agree with you that 3V will ensure the regulator is on at Vin = 5V, I need to know how low the Ven can be to guarantee operations b/c the input voltage to my enable pin is only guaranteed to 2.7V. Therefore, based upon the trend with respect to input voltage and enable voltage, as input voltage decreases, so should the enable voltage, but I need to know by how much. If you can give me a precise minimum for Vin =5V, that would be greatly appreciated.

    Thank you,
    Jared
  • Hi Jared,

    We do not measure the enable threshold at every Vin during our test procedure during our final test program. As such, we can only provide the typical data already provided for an input voltage of 5 V. Our tested parameters show that providing a minimum of 3 V for Ven will ensure that the regulator is enabled for an Vin 6 V and lower.

    Very Respectfully,
    Ryan