A signal conditioning integrated circuit includes both signal conditioning circuitry and memory devoted to storing end-user downloadable coefficients. In a preferred embodiment, the integrated circuit is an Application Specific Integrated Circuit (ASIC), and the end-user downloadable coefficients, based upon a mathematical equation pre-selected by the end-user, are pre-stored in the ASIC when a sensor device with which the ASIC is associated is calibrated. This results in a customized and more cost-effective and space-efficient signal-conditioning apparatus with improved functionality over that available in the prior art.