• State TI Thinks Resolved
  • Locked Locked
  • Replies 1 reply
  • Answers 1 answer
  • Subscribers 62 subscribers
  • Views 160 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

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.

TPS3840: >10V input

Adam Daluga
Expert 5680 points
Part Number: TPS3840
Other Parts Discussed in Thread: TPS3808

Hello,

I need to use the TPS3840 with more than 10V of power rail input to monitor (to detect ~5V of that), but the max input voltage of the TPS6840 is 10V. Is it okay to use voltage divider circuit with very high resistance(to reduce current consumption) for VDD? How much current should be needed in order to operate TPS3840 without any issues?

Or would you advise a different device with similar parameters to the TPS3840?

Thanks,

Adam

  • 0
    TI__Genius 9375 points

    Hi Adam,

    You can use the TPS3840 with a resistor divider as shown in section 9.2.3 of the datasheet, but be weary that there is a tradeoff between current consumption (resistance values) and accuracy, even to the point of the device not functioning as you mentioned. The rule of thumb is to generally be able to consume 100 times the supply current through the resistor divider (35 uA in the datasheet example) for the monitor accuracy. I understand this is quite high so I would recommend using another device that has a SENSE pin, such as the TPS3808. You can use the app note here to design your circuit accordingly. Using a SENSE pin is important due to the low current going through it (25nA in this case) that allows you to design the divider higher.

    Thanks,
    Abhinav.