• State
  • Locked Locked
  • Replies 2 replies
  • Subscribers 46 subscribers
  • Views 1693 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

LPV811/LPV812 Precision 425 nA Nanopower Operational Amplifiers for Piezo sensor Charge Input Signal Conditioning Circuit

user4846798
Prodigy 80 points
Other Parts Discussed in Thread: LPV812, LPV811

Hi, I would like to finding some Amp to replace the AD8608 in the Piezo Charge Input Signal Conditioning Circuit in below link.

Does the LPV811/LPV812 are suitable for Piezo  sensor  Charge Input Signal Conditioning Circuit?

Or do you have any low power suggestion for Piezo sensor Charge Input Signal Conditioning Circuit?

Thank you so much.

  • 0
    TI__Guru 53996 points
    Hello,

    It is possible, but beware that the LPV8xx are nanopower op-amps with a 8kHz bandwidth. The AD8608 is a 10MHz part.

    The LPV's are 1000x slower!! They are also nosier and have less output drive. These are the trade offs for micro-power operation.

    What bandwidths and noise floor are you planning? Lowering power involves many tradeoffs, particularly noise and bandwidth.

    Regards,
  • 0 in reply to Paul Grohe
    Prodigy 80 points
    Thank you Paul :

    I may not write my demand clear.
    My application is to use piezoelectric sensor, such as MFC, PVDF, or PZT to measure the dynamic strain.
    We are considering the Figure 2. Charge Input Signal Conditioning Circuit In CN0350 without using the AD7091R.
    However, our questions are
    1. The CN3050 mentions that "The AD8608 is chosen for this application because of its low bias current (1 pA maximum), low noise (12 nV/√Hz maximum) and low offset voltage (65 μV maximum). Power dissipation is only 15.8 mW on a 3.3 V supply. ". However, the 15.8 mW Power dissipation on a 3.3 V supply is higher for our wireless sensor networks application. If it is possible to find others to replace the AD8608 for lower Power dissipation? (close to or Below 1mW ).
    2. If you could recommend a piezoelectric Signal Conditioning Circuit and suitable op-amps to me?
    3. In my application, the frequency of the structure vibration usually below 20hz, so I think the kHz bandwidth is enough?

    Thank you so much.

    Lin