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INA332: Recommendation for piezoelectric sensor

Part Number: INA332
Other Parts Discussed in Thread: TLV2771

Hi team,

My customer is considering to use an instrumentation amp for a piezoelectric sensor.

They picked up INA332 because of its high input impedance and high CMRR.

Are there any recommended instrumentation amp or opamp suitable for piezoelectric sensor amplifier?

Other requirements are as follows.

1) Signal frequency range : 1kHz-2kHz

2) Gain : 40dB

3) Vcc = +5V

4) Cost competitive 

Regards,

Saito

  • Hi Takahiro,

    an instrumentation amplifier is typically used when an unwanted common mode signal has to be removed from the wanted signal or if the wanted signal is a true differential signal. Is this the case in your application?

    In most other applications a single OPAmp is sufficient. Two amplifier topologies can be used, the charge ampplifier and the voltage amplifier. The charge amplifier should be chosen when the piezo sensor is connected via a longer shielded cable or when a high bandwidth is intended. In most other cases a simple voltage amplifier is enough. Choose an OPAmp with a very high input impedance, though. The TLV2771 could be used. But there are many other suited OPAmps from TI available.

    You might also want to have a look at these two very nice appnotes:

    sloa033a.pdf

    slyt369.pdf

    Kai

  • Hi Takahiro,

    Agreed with Kai. I would start by taking a look at this app note for some more details, it discusses both charge mode and voltage mode circuits: http://www.ti.com/lit/an/sloa033a/sloa033a.pdf

    If you have any further questions, let me know!

    -Tamara