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OPA544: Supply Voltage to OPA544

Karthik Venkateshaiah
Prodigy 130 points
Part Number: OPA544

Dear team,

I am using OPA544 OP-amp to build gain amplifier. To power-up Op-amp i have positive 60V DC power source.My question is ,

1. To power-up OPA544 should i need both positive and Negative voltage ? or will it work only with positive supply?

2. If it works only with positive supply-voltage and  without negative-supply voltage, What is the minimum and maximum positive supply-voltage at that OPA544 will work ?

For the reference i am attaching the rough schematic.

Thanks and Regards,

Karthik Kumar Venkateshaiah

  • 0
    Guru 297660 points

    If V+ is connected to the 60 V output of the power supply, and if V− is connected to the ground of the power supply, then the OPA will work.

    It does not matter whether you call it "60 V" or "±30 V"; from the point of view of the OPA, these behave the same. What matters is only the voltage difference between the V+ and V− pins.

    The OPA544 needs between 20 V and 70 V.

  • +1 in reply to Clemens Ladisch
    Prodigy 130 points

    Hi Clemens,

    Thank you.

    Regards,

    Karthik Kumar Venkateshaiah

  • +1 in reply to Karthik Venkateshaiah
    TI__Guru* 93105 points

    Hi Karthik,

    When you operate the OPA544 from a single positive supply such as +60 V note that the input common-mode voltage (Vcm) and output voltage (Vo) negative lower limits needs to be slid upward more positive. For example, the OPA544 Common-Mode Negative Input Range for Linear Operation is [(V–) +6 V] min, and [(V–) +4 V] typ. If the negative supply V- is moved up from -35 V to 0 V, then the minimum voltage that can be applied to the non-inverting amplifier circuit you have shown will be [0 V + 4 V ] (typ) for linear operation. If you wanted to take the input voltage down to 0 V, then V- should be a negative supply of -6 V to assure linear operation.

    Similarly, the negative output voltage would have to be slid upward as well. The negative output swing is specified as  ([V–) +4] min and [(V–) +3.1] typ for Io = 0.5 A. It would be best to allow a little extra supply margin to make sure the output remains within its linear range so a -6 V supply would be good.

    Since the OPA544 is rated for a typical supply of +/-35 V (70 V) using a -6 V supply for V- would limit the V+ supply to about +64 V.

    Regards, Thomas

    Precision Amplifiers Applications Engineering

  • +1 in reply to Thomas Kuehl
    Prodigy 130 points

    Hi Thomas,

    Thanks a lot for the detailed explanation.

    Regards,

    Karthik Kumar Venkateshaiah