← 返回 JSSC 论文列表JSSC 2020第2期Medical & Bio180nmBiosignal
A 13.9-nA ECG Amplifier Achieving 0.86/0.99 NEF/PEF Using AC-Coupled OTA-Stacking Somok Mondal, Student Member , IEEE, and Drew A. Hall , Senior Member , IEEE
提出一种用于植入式传感器的超低功耗ECG放大器，采用AC耦合OTA堆叠技术提升噪声和功率效率。
13.2 nW (三堆叠版本), 18.7 nW (五堆叠版本), NEF 0.86, PEF 0.99
超低功耗ECG放大器OTA堆叠噪声效率植入式传感器
▸创新点1：采用AC耦合OTA堆叠技术，通过将调制/斩波信号应用于AC耦合的堆叠逆变器OTA，实现了噪声和功率效率的显著提升。
▸创新点2：噪声和功率效率提升，通过堆叠OTA技术，在相同的电流下实现了单个跨导的叠加，从而优化了噪声效率。
▸创新点3：实现超低功耗设计，三堆叠版本功耗仅为13.2 nW，五堆叠版本功耗为18.7 nW，显著优于现有超低功耗放大器。
▸创新点4：在180-nm CMOS工艺下实现了面积优化，三堆叠版本面积为0.18 mm²，五堆叠版本面积为0.24 mm²，进一步提升了集成度。
Abstract
An ultra-low power electrocardiogram (ECG) recording front-end intended for implantable sensors is pre- sented. The noise-limited, high power first stage of a two- stage amplifier utilizes stacking of operational transconductance amplifiers (OTAs) for noise and power efficiency improvements. The proposed technique involves upmodulated/chopped signals being applied to ac-coupled, stacked inverter-based OTAs that inherently sum the individual transconductances while reusing the same current, thereby enhancing the noise efficiency. Two prototype designs were fabricated in a 180-nm CMOS process. The three-stack version consumes 13.2 nW and occupies 0.18 mm 2, whereas the five-stack implementation consumes 18.7 nW and occupies 0.24 mm 2. State-of-the-art NEF and PEF metrics of less than unity, 0.86 and 0.99, respectively, are reported for the five-stack version. These correspond to ∼3× improvement in terms of energy efficiency compared to prior ultra-low power, sub-100-nW amplifiers.