A current recycling structure is used to boost the tail current source of an operational transconductance amplifier (OTA), improving the slew rate (SR). The proposed current recycling circuit detects the magnitude of the differential input voltage and adjusts the tail current source value in proportion to the absolute value of the detected differential input voltage. When a small input signal is applied, the quiescent current of the OTA does not change; therefore the proposed tail current boosting circuit does not degrade the voltage gain and bandwidth. The proposed boosted tail current source has been used to drive a two-stage class A-AB OTA to evaluate its performance. Post-layout simulation results using standard 0.18 µm 3.3 V CMOS process technology show SR improvement of approximately 396% at the cost of 21% increase in static power consumption compared to a two-stage class A-AB primary OTA. The proposed AB-AB OTA achieves 65.7 V/μs at a static power consumption of 0.38 mW when driving a 10 pF capacitive load.

电流回收结构用于升压运算跨导放大器 (OTA) 的尾电流源，从而提高压摆率 (SR)。所提出的电流再循环电路检测差分输入电压的幅度并与检测到的差分输入电压的绝对值成比例地调整尾电流源值。当施加小输入信号时，OTA的静态电流不会变化；因此，所提出的尾电流升压电路不会降低电压增益和带宽。所提出的升压尾电流源已用于驱动两级 A-AB 类 OTA 以评估其性能。使用标准 0.18 µm 3.3 V CMOS 工艺技术的布局后仿真结果显示，与两级 A-AB 类主 OTA 相比，SR 提高了约 396%，但静态功耗增加了 21%。当驱动 10 pF 容性负载时，所提出的 AB-AB OTA 在 0.38 mW 的静态功耗下实现了 65.7 V/μs。