CMOS exponential V-V converter with large DC operating range

A CMOS exponential voltage-to-voltage converter is presented. The concept of Taylor´s series expansion is directly derived from the square law of a transistor MOS biased in the saturation region. Based on 0.35 mum CMOS technology, Hspice simulations show a 15 dB linear range with a linearity error less than plusmn0.5 dB and a DC operating range from -0.7 to 1 V. The total power consumption is below 0.09 mW with a plusmn1.25 V supply vo.ltage.