Description of a digital AC ratiometric sensor conditioner
F. L. Lehman, R. F. Mockapetris · 2002
Ratiometric transducers such as strain gauge bridge transducers are commonly excited with AC sinusoidal waveforms. The transducer output must be amplified, demodulated and fil- tered in the process known as conditioning. Tradition- ally, sensor conditioning is accomplished using analog compo- nents for the functions of demodulation, zero suppression, ranging and filtering. An alternative is to sample and digitize the trans- ducer output as close to the transducer as possible, replacing the analog signal conditioning functions with digital processing. This article describes the design of a sensor conditioner that imple- ments AC excitation synthesis and signal conditioning using the digital signal processing techniques.