High-performance programmable grounded resistor and its applications

Programmable resistor and analog computational circuits are essential for many applications such as analog signal processing units, automatic gain control, neural, fuzzy and instrumentation systems. A high-performance programmable grounded resistor (PGR) using complementary metal oxide semiconductor (CMOS) technology is proposed in this paper. A highly linear CMOS resistor with equivalent resistance ranging from 9.4 to 1.5 k Omega is obtained by cancelling the non-linear term present in the current equation of an MOSFET working in the linear region. The proposed resistor operates on both positive as well as negative input voltage. The inherited features of PGR are simplicity, extensive control voltage range, wider bandwidth and low-power dissipation. Additionally, analog computational units such as multiplier, squarer and divider are also discussed as applications of the PGR. All circuits are implemented and simulated using TSMC 0.13 mu m CMOS technology in SPICE.