A new CMOS logarithmic current generator

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 ±0.5 V supply, consumes 0.3 µW, 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 µm CMOS process.

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