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.

OPA2171: Negative Input

Part Number: OPA2171

Dear Team,

Can I connect V+ to ground and V- to 12V for sensing the negative input signal?

I think the answer is yes, right?

BR

Kevin

  • Hi Kevin,

    you can do this, if you don't violate the absolute maximum ratings of OPA2171.

    Kai

  • Hi Kevin,

    No, you CANNOT do this. This will damage the device because the total supply voltage will be -12V.

    Thank you,

    Tim Claycomb

  • Hi Kevin,

    I think you meant to connect V- to -12V??

    Kai

  • Dear Team,

    I would like to connect V+ to ground and V- to 12V, by this I can sense the negative input signal, right?

    Or how can I deal with it?

    So is because the supply voltage min=0, so I can't connect V- to 12 V?

    But the supply voltage below mention can be +-18V

    BR

    Kevin

  • Hi Kevin,

    Connecting V+ to GND and V- to 12V will cause the supplies to be in reverse polarity and damage the device. The total supply voltage of the condition you provided is -12V (0V - 12V).

    When a datasheet says the supply voltage can be 36V (+/-18V) it means that if single supply operation is used you can use up to 36V and GND, if dual supplies are used you can use +/-18V. Where V+ is connnected to +18V and V- is connected to -18V for a total supply voltage of 36V.

    However, you can use any combination of dual supplies as long as V+ - V- does not exceed 36V. For example, +16V and -20V can be used because 16V - (-20V) = 36V.

    Can you please provide the supply voltages available, the input signal amplitude range (-12V to 12V?), and the output voltage range needed? I will try to recommend a circuit to give the desired results based on the info you provide.

    Thank you,

    Tim Claycomb

  • Hi Kevin,

    Its been a while since we have heard anything back from you. Do you have any system voltage levels needed for the design? 

    Thank you,

    Tim Claycomb