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TPS561201: EN Threshold

Andrew5821
Genius 4565 points
Part Number: TPS561201
Other Parts Discussed in Thread: TPS62135, TPS62125

Is the enable high threshold reasonably repeatable from device to device?  My application requires I implement a low battery cutoff and I would like to use the EN pin of the TPS561201 with a zener diode and resistor as a crude low battery shutdown circuit.

  • 0
    TI__Expert 4875 points
    Hi Andrew,

    The 1.6V and 0.8V EN threshold value are the extreme value that considered the variation of device to device. The real actual power up voltage should be lower than 1.6V and the real shut down voltage should be higher than 0.8V. I am not quite understand your application. Could you send a rough schematic for me?
  • 0
    TI__Guru**** 150880 points
    Hi Andrew,

    Does this app note help explain this? www.ti.com/.../slyt730.pdf

    We have TPS62135/6 (and the lower current TPS62125) which can disable at a precise Vin level with their precise EN pin.
  • 0 in reply to Anthony Lang
    Genius 4565 points
    Hi Anthony,

    I basically want to use the EN pin for an UVLO, either using a resistor divider or a zener diode from Vin to the EN pin, with a bias resistor to ground from the EN pin. Just wondering if the threshold tolerances on this device would realistically allow for that.
  • 0 in reply to Andrew5821
    TI__Expert 4875 points
    Hi Andrew,

    Like I mentioned, if considering device variation, there will be a range for both the EN high and low level. It is not a precise or fixed value. You could use a resistor divider to control the UVLO but it is not like the device UVLO which is very accurate. Do you need the distribution(max and min) of EN threshold for this device? I could check on our ATE data for you.
  • 0 in reply to Anthony Lang
    Genius 4565 points

    It doesn't have to be all that accurate. Mainly I'm putting in a last line of defense trying to prevent accidental deep discharging a 12V lead acid battery. So if it would turn off anywhere from 11V - 9.5V, that would be fine.  If you have some ATE data that might help.

  • 0 in reply to Andrew5821
    TI__Expert 4875 points
    Hi Andrew,

    using EN resistor divider may be challenge for your case since your on and off EN voltage is close. Using a zener diode voltage rating at around 9.5V could be a good idea. When Vin drops to 10.3V, all device will be turned off. When Vin rise above 11.1V, all the device will be turned on.