Design of CMOS current-controlled-gamma corrector

A high speed and low power CMOS current-mode current-controlled-gamma corrector composed of three approximating natural logarithm circuits and two approximating exponential circuits is proposed. By using companding design with only 17 transistors, we implement a low power and high speed current-controlled-gamma corrector. The gamma corrector was fabricated using a 0.35 μm CMOS technology. The measured bandwidth of the circuit could reach 120 MHz for an input range from 40 μA to 120 μA with a maximum power dissipation of only 1.18 mW.