An approach to essentially improve current efficiency for bulk-driven OTA

An approach to essentially improve the current efficiency for the bulk-driven circuits is presented. By employing an auxiliary amplifier cross-coupled to the gate of bulk-driven flipped voltage follower and input differential pairs, it achieves not only the gain-bandwidth improved, but also the slew rate significantly enhanced, which leads to a great boost in current efficiency. To validate our introduced method, the conventional and the proposed bulk-driven amplifiers are both designed under the CSMC 0.18 μm technology. Simulation results demonstrate that bulk-driven amplifier based on the proposed method achieves an 8 times slew rate and a 4 times bandwidth improvement with only a negligible increase in power consumption.