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OPA2675: Drive more current then expected

Genius 14629 points
Part Number: OPA2675

Hello Experts,

Posting this query on customer's behalf:

We are using OPA2675 in our design to amplify 3.3V to 5V. As per the calculation it supposed to consume 0.04A, but it is driving 480mA. We are applying +6V and -6V supply:

We tried with different feedback resistor.

Case 1 : R2=200 Ohms and R1=150 Ohms
Case 2 : R2=240 Ohms and R1=470 Ohms with load RL=50 Ohms
Case 3 : R2=240 Ohms and R1=470 Ohms

Still, we could see the amplified signal with some noise with greater than expected current.

For your assistance please.

73,
Archie A.

  • Hello Archie,

      For the first and third case, what are the load resistors? 

      How is the customer measuring the output? Is this using an isolation resistor + cabling/probe? If correct, what are these values? Is current consumption measured with their design load or when measuring output?

       Is this the value the amplifier in total is consuming (power supply reading) or amplifier's output current? 

    Thank you,

    Sima