This paper introduces a power-efficient super class-AB bulk-driven (BD) operational transconductance amplifier (OTA) in the subthreshold region suitable for driving a high capacitive load. An improved auxiliary differential amplifier is employed using a cross-coupled connection to the gate of the input core differential pairs and its adaptive biasing BD FVF differential pairs to boost the input core transconductance and slew rate in superclass-AB mode. The utilization of a partial positive feedback operation further improves the open-loop voltage gain, overall effective transconductance, and unity-gain frequency (UGF) with a sufficient phase margin of 93⁰. The Post layout simulation results of the proposed OTA in Cadence DFW-II platform using UMC 0.18 μm technology for a 0.5 V single supply and a capacitive load of 200 pF confirm enhancement of 22 times slew rate, 54.32 dB DC gain, and 75 times UGF achieved by the proposed design over its conventional counterpart with only a narrow increase of 1.19 times in power expenditure.

本文介绍了一种适用于驱动高容性负载的亚阈值区域的高能效超 AB 类体驱动 (BD) 运算跨导放大器 (OTA)。采用一种改进的辅助差分放大器，该放大器使用与输入核心差分对及其自适应偏置 BD FVF 差分对的栅极的交叉耦合连接，以提高超 AB 类模式下的输入核心跨导和压摆率。部分正反馈操作的使用进一步提高了开环电压增益、整体有效跨导和单位增益频率 (UGF)，并具有 93⁰ 的足够相位裕度。在 Cadence DFW-II 平台中使用 UMC 0.18 μm 技术对 0.