IEPE and Integrated Circuit Piezoelectric (ICP®) Explained


This article explains what IEPE means and whether it the same as Integrated Circuit Piezoelectric (ICP®).



IEPE refers to a type of transducer that is packaged with a built-in charge amplifier or voltage amplifier. IEPE is an initialism for Integrated Electronic Piezoelectric.

Integrated Circuit-Piezoelectric, or ICP®, is a trademark of PCB Piezotronics, Inc., and refers specifically to the IEPE devices that they manufacture. Their website contains a good introduction to piezoelectric accelerometers that can be found in the Additional Resources section.

IEPE technology is marketed under several recognizable brand names. Although other companies make IEPE based transducers, this does not imply that they are compatible with equipment that claims ICP® compatibility. One of the key variations from company to company is the amount of current necessary to power the sensor. Generally these sensors require a 4 mA current excitation, but be sure to verify this with the specific device being used.


Additional Information

Because the charge produced by an IEPE transducer is very small, the electrical signal produced by the transducer is susceptible to noise and sensitive electronics must be used to amplify and condition the signal. IEPE makes the logical step of integrating the sensitive electronics as close as possible to the transducer to ensure better noise immunity and more convenient packaging.

IEPE transducers consist of an instrumentation amplifier and a constant current source. The current source pumps current into the transducer. The circuitry inside of the transducer makes it behave like a resistor. The amount of physical phenomena (i.e. acceleration) the transducer is experiencing creates a proportional amount of resistance. Therefore, the returning signal is a voltage proportional to the phenomena. The amplifier allows you to set the input range to take maximum advantage of the incoming signal.