A SiGe BiCMOS instrumentation channel for extreme environment applications

An instrumentation channel is designed, implemented, and tested in a 0.5- m SiGe BiCMOS process. The circuit features a reconfigurable Wheatstone bridge network that interfaces an assortment of external sensors to signal processing circuits. Also, analog sampling is implemented in the channel using a flying capacitor configuration. The analog samples are digitized by a low-power multichannel A/D converter. Measurement results show that the instrumentation channel supports input signals up to 200Hz and operates across a wide temperature range of - 180 C to 125 C. This work demonstrates the use of a commercially available first generation SiGe BiCMOS process in designing circuits suitable for extreme environment applications.