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OPA171: Discrepancy in advertised and recommended supply voltage minimum

Part Number: OPA171
Other Parts Discussed in Thread: OPA320

The OPA171 web page and datasheet description state that the device is capable of operating with supplies as low as 2.7V (+/-1.35V). However, the "Recommended Operating Conditions" state that the minimum supply voltage is 4.5V (+/-2.25V).

Which minimum supply specification is correct? I would like to use this device with a single 3.3V supply.

Thank you,

Nate

  • Hi Nate,

    You can use this device with a single 3.3V supply, the 2.7V minimum spec is correct. I'll take a look at getting this discrepancy fixed, thank you for letting us know.

    Best,
    Paul
  • Nate, Paul,

    OPA171 has recommended 4.5V because some data sheet specifications mention higher supply voltage others are typical from 2.7V to 36V which means that 2.7V is father from typical than 36V would be.

    While the input is rail to rail, check out figure 5 to see what happens if input is > VCC - 1.5V
    While supply works at 2.7V , check out figure 15 to see how ICC and the resulting internal bias currents will be voltage sensitive and lower than at other supply voltages.

    Nevertheless VCC = 3.3V is usable. My question is why pick a 36V device for a 3.3V application? TI has a vast selection of 5V (max) op amps.
  • Ron,

    Thanks for the clarification.; that makes more sense now. As you recommended, I ended up selecting the OPA320 (5V part) for this application instead.

    Nate