A high-speed wide-range low-distortion constant-gm cell design for GHz applications

A wide-range, low-distortion, constant-gm building block called pseudo-differential pair (PDP) suitable for high-speed applications is presented. For a 0.18/spl mu/m CMOS typical process, 1.8V supply, simulation results show that over 1.1V/sub PP/ differential input range, gm variations can be maintained within /spl plusmn/0.15%; at 100MHz, total harmonic distortion (THD) < -64dB; at 10GHz, THD < -39dB. It Is the fastest wide-range low-distortion constant-gm reported to date.