A new CMOS logarithmic current generator

Abstract

A new CMOS current-mode controllable low-voltage and low-power logarithmic function circuit is proposed. The circuit provides good dynamic range, controllable output, and reasonable accuracy and it is insensitive to temperature variations. The circuit operates with $\pm $0.5 V supply, consumes 0.3 $\mu $W, and has a -3 dB frequency of 2.4 MHz. The functionality of the proposed design is confirmed using Tanner T-spice with 0.35 $\mu $m CMOS process.