17.2 A 0.0013mm2 3.6μW nested-current-mirror single-stage amplifier driving 0.15-to-15nF capacitive loads with >62° phase margin

This paper introduces a nested-current-mirror (NCM) single-stage amplifier to advance its GBW-to-power/area efficiency and CL drivability beyond the multi-stage designs, while preserving a rail-to-rail output swing. The fabricated NCM amplifier demonstrates 33x higher GBW and 47dB higher DC gain than those of a typical differential-pair (DP) amplifier at equal power and area. By benchmarking with the recent three-stage amplifiers, this work improves FOM₁ [=GBW.CL/(Power.Area)] by >6.6x, and upholds a comparable FOM₂ [=SR.CL/(Power.Area)]. The C_L drivability is >10x wider, while avoiding the stability limit at the heavy-C_L side. These results justify advanced single-stage amplifiers as a potential replacement for multi-stage designs in traditional (e.g. 100pF/m coaxial cable) and advanced (e.g. low temperature polysilicon LCD) buffer interfaces.