DI-5BICP-Peak and DI-5BICP-RMS Amplifiers

for ICP-style Piezoelectric Transducers


Models DI-5BICP-PEAK and DI-5BICP-RMS provide a cost-effective method for interfacing common ICP® style transducers to DATAQ Instruments' wide range of data acquisition products. ICP® transducers, such a piezoelectric accelerometers and microphones, feature built-in signal conditioning and low impedance outputs, but do require an external excitation power supply. This must be provided as a current-mode source, since the transducer's output resistance changes as a function of applied force or acceleration. Constant current excitation transforms this variable resistance to a variable voltage that is directly proportional to the measured phenomena.

The constant current source of DI-5BICP amplifiers yields 5.3 mA DC excitation with a compliance voltage of 8-12 VDC. The amplifiers feature AC coupling to remove the DC component of the transducer's signal so that only dynamic waveform information is passed through the amplifier. Gain for both amplifier models is fixed to 1, although many of DATAQ Instruments data acquisition products feature programmable gain per channel. This feature may be applied to yield greater sensitivities when required.

Model DI-5BICP-PEAK is simply a unity gain amplifier with a built-in constant current excitation source. This amplifier should be used when the application demands a complete reproduction of the force or acceleration waveform. Model DI-5BICP-RMS expands on this basic design by providing a true rms converter that is useful for lower speed trending of the true rms value of the applied force or acceleration.

Note: Both modules come with galvanic isolation (or electrical isolation) between power supply, sensor, and analog output.

ICP is a registered trademark of PCB Piezotronics, Inc.