Input coupling, dc coupling or ac coupling, Input for iepe – ADLINK PCI-9527 User Manual
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Operation Theory
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ADLINK Technology Inc.
Copyright 2010
Input Coupling, DC Coupling or AC Coupling
The input coupling can be AC or DC. When you select DC cou-
pling, the DC offset present in the input signal is pass to ADC. Use
the DC coupling configuration if the signal source has a small
amount of offset voltage or if the DC content of the signal is impor-
tant.
When you select AC coupling, the DC offset present in the input
signal is removed. Use the AC coupling configuration if the DC
content of the input signals that you want to reject.
AC coupling enable a high pass R-C filter through the input signal
path. The corner frequency (-3dB) is about 3Hz.
Input for IEPE
For applications that require sensors such as accelerometer or
microphone, PCI-9527 provides an excitation current source.
The common excitation current is usually between 4mA for these
IEPE sensors. A DC voltage offset is generated because of the
excitation current and sensor impedance. When enable the IEPE
current sources, the PCI-9527 will set input configuration to AC
coupling automatically.