Variability Analysis of MOS Differential Amplifier

Abstract

Variation characteristics in MOS differential amplifier are evaluated by using the concise statistical model parameters for SPICE simulation. We find that the variation in the differential-mode gain, A_dm, induced by the current factor variation, Δβ₀, in the I_d-variation of the differential MOS transistors is more than one order of magnitude larger than that induced by the threshold voltage variation, ΔV_th, which has been regarded as a major factor for circuit variations in SoC's ⁽²⁾. The results obtained by the Monte Carlo simulations are verified by the theoretical analysis combined with the sensitivity analysis which clarifies the specific device parameter dependences of the variation in A_dm.