IEEE Trans Biomed Circuits Syst. 2021 Jun;15(3):509-521. doi: 10.1109/TBCAS.2021.3083276. Epub 2021 Aug 12.
In this paper, a fully integrated active rectifier with triple feedback loops is proposed to enhance power conversion efficiency (PCE) over a wide loading range by calibrating both the gate transition timing and power switch size. The on- and off-transitions of the power switches are calibrated using a hybrid delay-based gate control circuit (HDGCC) with hybrid feedback loops. Conventional active rectifiers that only focused on calibrating the gate transition timing of a NMOS power switch with a fixed power switch size exhibit a low PCE when the loading condition deviates from the predetermined range. Thus, an automatic size selector based on a third feedback loop is proposed, which changes the power switch size based on the loading condition and ensures a stable operation of the hybrid loops by maintaining the voltage drop across the NMOS switches. An active rectifier was fabricated using the standard 0.18 μm CMOS process. The effectiveness and robustness of the two-dimensional calibration were verified through measurements under an AC input voltage ranging from 2.5 to 5.0 V and an output power ranging from 1.25 to 125 mW. The peak voltage conversion ratio and peak PCE were 97.6% and 95.0%, respectively, at R = 500 Ω.
本文提出了一种具有三重反馈环的全集成有源整流器，通过校准栅极转换时间和功率开关尺寸，在宽负载范围内提高功率转换效率 (PCE)。功率开关的导通和关断转换由具有混合反馈环的混合延迟栅极控制电路 (HDGCC) 进行校准。传统的有源整流器仅关注校准 NMOS 功率开关的栅极转换时间，且功率开关尺寸固定，当负载条件偏离预定范围时，其功率转换效率 (PCE) 较低。因此，提出了一种基于第三个反馈环的自动尺寸选择器，根据负载条件改变功率开关尺寸，并通过保持 NMOS 开关两端的电压降来确保混合环的稳定运行。该有源整流器采用标准的 0.18 μm CMOS 工艺制造。通过在交流输入电压范围为 2.5 至 5.0 V 和输出功率范围为 1.25 至 125 mW 的条件下进行测量，验证了二维校准的有效性和鲁棒性。在 R = 500 Ω 时，峰值电压转换比和峰值 PCE 分别达到 97.6%和 95.0%。
