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TLV2374-Q1: Negative overvoltage for Vin pin

Yuta Kurimoto
Expert 8780 points
Part Number: TLV2374-Q1

Hello Team,

I just got some questions from customer.

They have been evaluating TLV2374QPWRQ1 and they faced some problem with input voltage spec.

TLV2374-Q1 datasheet specifies the input voltage range as -0.2V ~ Vdd+0.2V. However in customer's case, the input voltage can drop to -1.0V.

Q1. If customer can limit the input current, does TLV2374-Q1 withstand with the -1.0V input voltage? If yes, how much input current does customer need to limit?

Q2. Is there any other method to withstand -1.0V input voltage?

Q3. Is there any other opamp which can withstand -1.0V input voltage? Pin-compatible device is preffered.

Let me know if you have any question,

Thanks,

Yuta Kurimoto

  • 0
    Guru 140200 points
    Hi Yuta,

    in any case you should limit the input current to less than 10mA, as mentioned in the datasheet. This will at least prevent the chip from becoming damaged. A simple resistor in series to the input can do this.

    Another problem is, that the OPAmp can start to work improperly when the input signal exceeds the recommended common mode input voltage range which is 0V...Vdd. Eventually even furtherly limiting the input current can help. But there's no guarantee. Try a current limiting resistor of 10k. This will limit the input current to under 100µA.

    Of course, there are some other remedies. You could introduce a small negative supply voltage. Another cure is to clamp the input voltage by the help of a low leakage Schottky diode. Or you could use a voltage divider to decrease the -1V input signal. Or you could even combine some of these measures.

    Kai
  • 0
    TI__Genius 15410 points

    Hello Kurimoto-san,

    Kai is correct is that limiting the current flowing into the input below 10mA when the ESD diodes turn on will protect the device. The current limitation can be found in the Absolute Maximum Ratings Table in the datasheet. You could also add a clamping diode to the input.

    For more information on protecting the device against an Electrical Overstress event I recommend watching our TI Precision Lab Videos on EOS.

    Thank you,

    Tim Claycomb