n Chemical Sensors n Smoke Detectors

Many popular sensors have output impedances greater than several MW, and the associated signal conditioning circuitry must be carefully designed to meet the challenges of low bias current, low noise, and high gain. A large portion of this section is devoted to the analysis of a photodiode preamplifier. This application points out many of the problems associated with high impedance sensor signal conditioning circuits and offers practical solutions which can be applied to practically all such sensors. Other examples of high impedance sensors discussed are piezoelectric sensors, charge output sensors, and charge coupled devices (CCDs)