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TLV62085: suitable enable dealy to wait stabilized VIN

Diego Perez17
Prodigy 130 points
Part Number: TLV62085

Hi,

I would like to confirm if it is suitable to perform a EN delay through a RC filter at EN pin. The target is enable output voltage when the VIN voltage reaches at least 95%, VIN has a slow start (10ms 0V to 3,3V). I read the datasheet to check if EN pin has schmitt trigger input but, datahseet don't say if it has.

The question is: Is it suitable to set a RC filter at EN pin?, considering that EN signal will be a very slow edge.

BR

  • 0
    TI__Expert 8420 points

    Hi Diego,

    As far as I know it is a normal comparator with the threshold between 0.4V and 1V. I can also double check with the designer.

    In the electrical specification table of the datasheet it is specified in this way .

    You should read it this way: to make sure the device is  enabled Ven should be above 1V . But some IC's may already be enabled at 0.6V, 0.8V or 0.9V for example.

    Regards,

    Sabrina

  • 0 in reply to Sabrina
    Prodigy 130 points

    Hi Sabrina,

    I need to delay output from inpunt. so, I will add an RC at EN pin as in schematic is sohwed.


    As you say, the inpunt is a normal comparator, the EN signal will reach 3.3V but it will do as a RC slow signal. I think it could be a problem when the signal will be arround of enable point, becasuse it could be enable several times due to noise.


    Are there any timing restriction on the edge of EN signal?


    I send a capture of my IN, OUT and EN signal.

    Thanks, BR.

  • 0 in reply to Diego Perez17
    TI__Expert 8420 points
    Hi Diego ,

    the EN pin is a logic gate input with a hysteresis, there are no state where a DC value can enable and disable the device at the same time. I don't see noise being a problem as it would be itself filtered by the RC circuit. It is common to use a RC enable delay circuit on the EN pin as on your schematic, I have seen often other customer doing so. The only thing is, the enable delay time cannot be precisely set for this device.

    If you need a precise enable delay time you can take look at the TPS62810

    Regards
    Sabrina