Tunable Highly Linear Floating-Gate CMOS Resistor Using Common-Mode Linearization Technique

In this paper, an implementation of a tunable highly linear floating resistor that can be fully integrated in CMOS technology is presented. The second-order effects of a single MOS transistor operating in the triode operation regime are described, and a common-mode linearization technique is applied to suppress these nonlinearities. This technique is implemented by utilizing a low-power circuit design strategy that exploits the capacitive coupling and the charge storage properties of floating-gate transistors. The resistance of the proposed circuit is tuned by utilizing the Fowler-Nordheim tunneling and hot-electron injection quantum-mechanical phenomena. We demonstrate the use of this resistor in highly linear amplifier. We present experimental data from the chips that were fabricated in a 0.5- CMOS process. We show that this resistor exhibits 0.024% total harmonic distortion (THD) for a sine wave with amplitude. Also, we show the programmability of the amplifier gain using the proposed tunable resistor.