Integrated MOS four-quadrant analog multiplier using switched capacitor technology for analog signal processor ICs

A fully integrated four-quadrant analog multiplier (4-QAM) based on switched capacitor technology is developed using a short-channel MOSFET fabrication process for realization of high-speed and high-density analog signal processor ICs. This 0.6-mm/SUP 2/ 4-QAM, consisting of a pair of MOSFETs, three op. amps., and a switched capacitor circuit, does not require any external circuits to perform the four-quadrant analog multiplication. The characteristics are measured, showing a total harmonic distortion of less than -50 dB for two input signals of 1 V/SUB p-p/, a dynamic range of more than 75 dB, and an operation speed of more than 2-MHz clock rate. In addition, the principal factors of the nonlinear distortion are analyzed. Application of the 4-QAM to convolvers and correlators is also discussed.