COMPANDER CIRCUITS IMPROVE TRANSDUCER DATA QUALITY

Abstract

AC-coupled transducers such as crystal accelerometers and microphones can produce a large dynamic range of signals, but the expected level from such devices in an actual test situation may be difficult to predict. Use of compander circuits intended for telephone and “hi-fi” systems can increase dynamic range and accuracy of the signals from such devices and reduce noise at low levels and clipping at the top of the range. Companders (COMPressor plus expANDER) can be used in single- or double-ended modes depending on the data requirements. They do introduce predictable artifacts of their own, but many of these can be removed.