The examined class of circuits includes voltage multipliers, current multipliers, linear V-I convertors, linear I-V convertors, current squaring circuits, and current divider circuits. Typical for these circuits is an independent control of the sum as well as the difference between two gate-source voltages. As direct use is made of the basic device characteristics, only a small number of transistors is required in the presented circuits.
Bult, K., & Wallinga, H. (1979). A class of analog CMOS circuits based on the square-law characteristic of an MOS transistor in saturation. IEEE journal of solid-state circuits, 22(3), 357-365. https://doi.org/10.1109/JSSC.1987.1052733