A CMOS front-end IC for fluctuation enhanced sensing

Fluctuation enhanced sensing (FES) is newly coined term for a highly sensitive and selective stochastic fingerprinting technique for chemical and biological sensing. FES deals with the characterization and discrimination of sensed analytes using the microscopic fluctuations of the sensor signal around the mean value. The paper demonstrates a low cost, low power CMOS implementation of a front-end for fluctuation enhanced sensing in a TSMC 0.18/spl mu/ CMOS technology. It consists of a transimpedance amplifier and low pass filter array with 8 distinct cut-off frequencies acting as a coarse on-chip spectrum analyzer for feature extraction within individual frequency band. The gain of the front-end circuit is at least 87dB with a total power consumption of just 1.1mW. The equivalent input current noise level is under 7nA/sub RMS/.