Free class-AB flipped voltage follower using bulk-driven technique

A new configuration of the flipped voltage follower (FVF) offering class-AB operation is presented. The idea uses a bulk-driven transistor instead of the constant current source of the typical FVF topology. This feature enhances the sourcing capability for class-AB operation and the symmetrical slew rate. The key element is changing the basic structure of the original FVF circuit with no additional devices. A detailed analysis of the circuit and simulations using Spice are presented. The experimental results from a manufactured circuit prototype using CMOS 0.35 μm technology demonstrate the feasibility of the proposal.