An integrated readout amplifier for instrumentation applications in smart sensor systems is presented. A fully integrated CMOS version of such an amplifier has been developed using switched-capacitor techniques. The amplifier system provides differential input capability, programmable amplification, clock generation, and low-pass filtering on the chip. The output signal is continuous in time and the system can be used without any of the special precautions necessary for sampled-data circuits. Emphasis was put on high PSRR (-63 dB at DC), low noise (10- mu V/sub rms/ input equivalent wideband noise) and offset, low harmonic distortion, and small amplification error ( >