Analysis, Comparison, and Experimental Validation of a Class AB Voltage Follower With Enhanced Bandwidth and Slew Rate

This paper describes a bandwidth (BW)and slew rate (SR)-enhanced class AB voltage follower (VF). A thorough small signal analysis of the proposed and a state-of-the-art AB-enhanced VF is presented to compare their performance. The proposed circuit has 50-MHz BW, 19.5-V/μs SR, and a BW figure of merit of 41.6 (MHz × pF/μW) for C
_L
= 50 pF. It provides 13 times higher current efficiency and 15 times higher BW than the conventional VF with equal 60-μW static power dissipation. The experimental and simulation results of a fabricated test chip in the 130-nm CMOS technology validate the proposed circuit.