A Power-Efficient Active-RC Filter Using Passive Integrator and OTA With Push-Pull Output

作者：Liangbo Lei, Cong Tao, Zhipeng Chen, Zhiliang Hong, Yumei Huang · 发表于：IEEE Transactions on Circuits and Systems I Regular Papers · 年份：2025 · DOI：10.1109/tcsi.2025.3554894 · 被引用次数：4 · 研究领域：Analog and Mixed-Signal Circuit Design、Advanced Adaptive Filtering Techniques、Digital Filter Design and Implementation

This paper presents a power-efficient fourth-order, 50-MHz active-RC filter with high dynamic range (DR). Unlike conventional Tow-Thomas biquads, the proposed design employs a passive integrator as the second pole to reduce power consumption, enhance noise performance, and facilitate frequency compensation. The active integrator features a two-stage operational transconductance amplifier (OTA) with a push-pull output, ensuring linearity and reducing the OTA’s gain requirements. Fabricated in standard 0.18-μm CMOS technology, the proposed filter achieves an in-band (IB) input third-order intercept point (IIP3) of +29.9 dBm at 30 MHz and an input-referred IB integrated noise of 163.8 μVRMS, while consuming 5.4 mW for a 50-MHz bandwidth.