Integrated Electronics Piezo-Electric
IEPE is a set of initials for “Integrated Electronic Piezo Electric”. It is a standard for electronics in transducers (like accelerometers and microphones) that have built-in amplifiers.
ICP is short for “Integrated Circuit-Piezoelectric”. ICP is a trademark name of PCB Corporation for their proprietary implementation of IEPE.
Other trademark names of IEPE from different companies include CCLD, IsoTron or DeltaTron.
Most IEPE sensors work at a constant current between 2 and 20 mA. A common value is 4 mA.
Supplying the IEPE sensor with constant current, results in a positive bias voltage, typically between 8 and 12 Volts, at the output.
The supply or compliance voltage of the constant current source should be 24 to 30 V which is about two times the bias voltage.
Compliance Voltage example calculation
Example sensor specifications:
|Constant Current Excitation||2 .. 20 mA|
|Excitation - Compliance Voltage||18 .. 30 Vdc|
|Bias Voltage||7 .. 12 Vdc|
SIRIUS ACC module specifications:
|Excitation||2, 4, 8, 12, 16 or 20 mA|
|Compliance Voltage||25 V|
Excitation - Compliance Voltage minimum required = 500 g * 10 mV / g +12 V = 17 V
This (17 V) is within the compliance voltage of the SIRIUS ACC amplifier specifications.
Jernej Kovačič, 13.05.2020