In-situ Evaluation of V_<th> and AC Gain of 90nm CMOS Differential Pair Transistors

Abstract

In-situ DC measurements of individual transistors in a differential pair of an analog amplifier derive threshold voltage, V_<th>, of 1.0V transistors in a 90nm CMOS technology. On-chip continuous time waveform monitoring is used to evaluate AC response of the same amplifier. The distribution of AC gain versus V_<th> of transistors within amplifiers is captured. The degradation of common-mode rejection property is observed for an amplifier with intentionally introduced mismatches to the pair of transistors.