Method and apparatus for decreasing the interference and noise sensitivity of a ratiometric converter type of circuit

摘要

A ratiometric converter (12) receives a sense signal AIN+, AIN- and a reference signal VREF+(EXT), VREF-(EXT) and provides an output signal COUT which is proportional to the sense signal and inversely proportional to the reference signal. Electromagnetic interference and noise coupled onto the sense and reference lines are effectively removed by converting the sense and reference signals to digital signals and filtering through digital filters (22, 30).A divider circuit (24) then divides the filtered digital sense signal by the filtered digital reference signal to provide the output signal.