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Original question:

OPA547EVM: using OPA547/OPA 548 Evaluation Module as a current amplifier

OPA547EVM: OPA547EVM

Ahmed Ahmed38
Prodigy 240 points
Part Number: OPA547EVM
Other Parts Discussed in Thread: OPA547

Dear TI engineers

I would like to use the improved Howland circuit using the OPA547EVM PCB. my purpose is to drive a MEMS resistor of a few ohms typically from 10 to up to 500 ohm or even 1k with an AC current. as an input i want to use a voltage function generator at low frequency less than 30Hz. Do you think the OPA547EVM is fit for that purpose and is it plug and play or do i have to solder different components. i was thinking of making the circuit but if the TI PCB is fit i ll just buy it. awaiting your feedbkack.

Thanks for your inputs

Ahmed

  • 0
    TI__Guru* 93105 points

    Hello Ahmed,

    The OPA547 EVM is designed to accommodate the Improved Howland Current Pump components. You will find the information in EVM User's Guide in Section 7, "Improved Howland Current Pump Configuration Setup."

    Since everyone's circuit requirements are different, you will have to remove and add components from/to the EVM board to meet your circuit's design. This does require moderate soldering skills of surface mount components. However, the EVM does provide the quickest path to having an assembled circuit and the heat sink requirement is already taken into consideration.

    Regards, Thomas

    Precision Amplifiers Applications Engineering

  • 0 in reply to Thomas Kuehl
    Prodigy 240 points

    Dear Thomas

    Thanks a lot for the clear feedback. my purpose is for a lab experiment so i need some flexibility having to sold surface mount component my not be straightforward as the AC source will be part of a setup.

    I am going to do it as displayed figure 10 of the datasheet. considering my current requirements say up to a mA at low frequency (not much heat dissipation) do you recommend me to order the OPA 547 or 548?

    Regards

    Ahmed

    PS we can close the other inquiry as suggested

  • 0 in reply to Ahmed Ahmed38
    TI__Guru* 93105 points

    Hello Ahmed,

    If the output current is low, tens or a few hundred milliamperes, the OPA547 is well suited for the application.

    Please close this e2e inquiry from your end.

    Regards, Thomas

    Precision Amplifiers Applications Engineering