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  • TI Thinks Resolved

LM339: LM339 or TL074(Selection)

Prodigy 190 points

Replies: 4

Views: 138

Part Number: LM339

Hi,

I have an application(Solar inverter) where I have to sense AC/DC voltages, current and generate reference voltages (1.65V and 2.5V). I was confused between LM339 and LM074 quad amplifier.

Also, on what parameter I should compare amplifiers when using in a solar application.

Regards,

Archit

  • Hi Archit,

    the LM339 is a comparator, but no OPAmp. And there's no LM074, but only the TL074. This is a FET-OPAmp.

    Is your circuit supplied by a single supply voltage or by a bipolar supply voltage?

    Can you show a schematic?

    Kai
  • In reply to kai klaas69:

    Hi Kai,

    Yes, It is TL074.

    Right now I am following the sensors schematic from the Ti Design Document --TIDM-HV-1PH-DCAC.

    DC Voltage Sensing.

     AC voltage sensing.

    1.65V from 3.3V

    I am open to both types of supply voltages(Unipolar or bipolar) as I haven't selected the IC yet.

    Ti is using OPA4350 in their circuit which utilizes a unipolar supply. Though I have also seen the sensing solution implemented via TL074 also.

    I also wanted to know the role/effects of supply in implementing the sensing part if I am using the above two schematics for AC and DC voltage sensing.

    Regards,

    Archit.

  • In reply to archit khandelwal:

    Hi Archit,

    the TL074 is an OPAmp of the past, almost a dino under the OPAmps. The common mode input voltage range is very limited, which wasn't an issue at the time when OPAmps where powered by a bipolar +/-15V supply voltage. But modern customers need OPAmps which can run at a low single supply voltage. The OPA4350, which is a modern RRIO OPAmp, fullfills this need.

    Another disadvantage of TL074 is its rather high input offset voltage. Because of that I have widely used the TL052/54 for measuring purposes in the past. By the way, the OPA4350 also has a low input offset voltage, even lower than the TL052.

    Kai

  • In reply to kai klaas69:

    Archit
    There has not been any new questions posted on this thread in a while, so I am going to close this post. If you have any additional questions, feel free to hit reply and the post will be re-opened.
    Chuck

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