AD7667 input question

hi all:

      Looking at the AD7667 datasheet, I have troubles understanding Figure 45. Using the AD7667 in 16-Bit Bipolar and/or Wider Input Ranges.

Why the op amp can convert  ±10V to 0-2.5V. Should U2 connect the analog input signal to R2 and R3? But the gain is not right.

thanks

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  • Hi lzhang791,

    If I understand you correctly, you want understand as this circuit convert +/-10 V input range to 0-2.5 V output. You can derive the transfer function of this circuit:

    General view: Vout=Vin*k+b, where k is input signal gain, b is constant.

    In this case:

     If you don't understand how to do it, I can help you.

    As result, output range

     

    I hope this help you.

    Regards,

    Kirill

Reply
  • Hi lzhang791,

    If I understand you correctly, you want understand as this circuit convert +/-10 V input range to 0-2.5 V output. You can derive the transfer function of this circuit:

    General view: Vout=Vin*k+b, where k is input signal gain, b is constant.

    In this case:

     If you don't understand how to do it, I can help you.

    As result, output range

     

    I hope this help you.

    Regards,

    Kirill

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