A Low-Power Wide-Linear-Range Transconductive Amplifier

Abstract

In the past few years, engineers have improved the linearity of MOS transconductor circuits 12, 5, 10, 11, 19, 20, 26, 28, 29, 32]. These advances have been primarily in the area of above-threshold, high-power, high-frequency, continuous-time filters. Although it is possible to implement auditory filters (20Hz- 20khz) with these techniques, it is inefficient to do so. The transconductance and current levels in above-threshold operation are so high that large capacitances or transistors with very low W / L are required to create low-frequency poles, and area and power are wasted. In addition, it is difficult to span 3 orders of magnitude of transconductance with a square law, unless we use transistors with ungainly aspect ratios. However, it is easy to obtain a wide linear range above threshold.