Electronic – Charge Model vs Voltage Model for Piezo Electric Sensor

instrumentation-amplifierpiezoelectricitysensor

The following document describes signal conditioning circuits for Piezeoelectric sensors. I was interested in knowing which model should I use when designing signal conditioning circuit for piezelectric sensor.

http://www.ti.com/lit/an/sloa033a/sloa033a.pdf

Best Answer

If you can limit the load capacitance of the cable and amplifier, you can use the voltage model. This requires that no cable is involved as cables tend to add 20~30 pF/ft.

Otherwise the charge model must be used and a charge amplifier is required. This is how accelerometers work with cables from sensor to amp.