• State TI Thinks Resolved
  • Locked Locked
  • Replies 3 replies
  • Answers 1 answer
  • Subscribers 63 subscribers
  • Views 70 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

Original question:

TLV809E: Strange behaviour

TLV809E: TLV809E always driven low at when connected to load.

Shiyamsundar Chandrabose
Prodigy 10 points
Part Number: TLV809E

Tool/software:

HI All, I have simple circuit, with (High & low) issue.

I am using TLV809E (2.6V) to monitor the voltage

If Voltage at 12V, i should get high to trigger the N-Mosfet

If voltage below 10V, then i should get low. 

But in my case, i am always getting low from TLV809E.   

If device isolated from MOSFET, it works fine. When i connect to FET, its always driven low.

What's really goes wrong on this?

  • 0
    TI__Intellectual 780 points

    Hello Shiyamsundar,

    I would need some more information before I can proceed.

    When you say that you are getting low from the TLV809E, where are you reading this low value from?

    When you say the device is isolated from the MOSFET, is the MOSFET being removed or is there another way that the device is being isolated?

    If the TLV809E is swapped with another TLV809E, is the same behavior being observed?

    If the N-MOSFET is swapped out with another N-MOSFET, is the same behavior being observed?

    Regards,

    Anusha

  • 0 in reply to Anusha Adira
    Prodigy 10 points

    By removing R400, TLV809E isolated from load. 

    Then we are receiving proper response from TLV chip

    1. high (2.8V at 12V)

    2. Low (below 2.54V)

    > if we populate R400, then TLV809E chip always in 0V position.

    > few times we are observing pulsed output  like below image.

    Probing U21.2 pin.

    NMOS and TLV809E, both separately working fine by removing R400.

    While we connect TLV with load, then observing always low, even at constant 12V.

  • 0 in reply to Shiyamsundar Chandrabose
    TI__Intellectual 780 points

    Hi Shiyamsundar,

    It seems that the input is lacking enough charge to power the entire system. By adding a bypass capacitor of 1µF should ensure that there is enough charge. Please note that by adding a bypass capacitor, it will add a delay in how quickly a change in the 12V rail will be reflected on the VDD pin. If the 1µF is not enough, try increasing the capacitance. 

    Regards,

    Anusha