Improved Linearity CMOS Active Resistor with Increased Frequency Response and Controllable Equivalent Resistance

A new active resistor circuit is further presented, with main advantages of improved linearity, small area consumption and improved frequency response. An original technique for linearizing the I(V) characteristic of the active resistor is proposed, based on the simulation of the Ohm law using two linearized differential amplifiers, a multiplier and a current-pass circuit. The controllability of the active resistor circuit is given by the possibility of modifying the value of the equivalent resistance by changing the ratio of a control voltage and a control current. Additionally, the value of the simulated resistance is independent on technological parameters, with the result of improving the circuit accuracy. The errors introduced by the second-order effects is also strongly reduced, while the area consumption of the active resistor is minimized by replacing the classical MOS transistor with FGMOS (floating gate MOS) devices