Design and implementation of a new four-quadrant MOS analog multiplier

A four-quadrant MOS analog multiplier is proposed using the quarter-square technique, which is based on the quadratic characteristics of an MOS transistor operating in the saturation region and the difference operation of four identical sourced-coupled differential amplifiers. The multiplier has a simple configuration and a large dynamic range over a wide frequency range, since each input signal passes only one transistor to reach the output. The operation of the multiplier was analyzed in detail, and the second-order effects were also analyzed. The proposed circuit was fabricated in 12-V p-well CMOS process with a 5-m minimum feature. The measured results show that linearity error is less than 1% for 5-V_p-p input at ±5 V supply voltage, and the-3 db bandwidth is 30 MHz.