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LM2904-Q1

Differential Input Voltage Range Equal to Maximum-Rated Supply Voltage: − Non-V Devices . . . ±26 V − V-Suffix Devices... ±32 V

What do you mean by this  ±26 V?  How do use it?

  • Hi Jeffrey,

    The spec you are looking at is the maximum input differential voltage. This means that the maximum voltage difference between the IN+ and IN- pins of the device can be no more than +26 V (with respect to IN-) or -26 V (with respect to IN-).

    For example, if we hold the voltage at IN- to 0V, then IN+ can go as high as 26V (a Vdiff of +26V). Alternately, if we hold IN- to 26V, IN+ can go as low as 0V (a Vdiff of -26V).

    If you exceed that range, you will possibly damage the device and it will not perform as expected. You use this spec to make sure that the input signal you are applying to this device can be safely handled.


    I hope that is clear.

    Best,
    Paul

  • Clarified my earlier answer - typo and slight error.

    -Paul
  • I still don't quite understand, for example IN- at 0V, IN+ is 0~+26 or -26~+26.
  • Hi Jeffrey,

    The spec is really telling you what the maximum voltage difference between the two input pins can be. There are two conditions which must be met:

    1. Voltages on IN+ and IN- need to be between 0 and 26V.

    2. Using IN- as the reference, Vdiff = (V_IN+ - V_IN-).

    If both of these conditions are satisfied, then the input is safe for the device. Using the example you gave, if you hold V_IN- at 0V, then the acceptable range for V_IN+ is 0 to 26V.

    -Paul