Son Chanyoung, Koh Seok-Tae, Jeon Hyuntak
School of Semiconductor Engineering, Chungbuk National University (CBNU), Cheongju 28644, Republic of Korea.
School of Electrical Engineering, Chungbuk National University (CBNU), Cheongju 28644, Republic of Korea.
Micromachines (Basel). 2025 Mar 29;16(4):398. doi: 10.3390/mi16040398.
This paper presents a low-power photoplethysmography (PPG) readout system designed for wearable health monitoring. The system employs a differential current mirror (DCM) to convert single-ended PPG currents into differential voltages, inherently suppressing DC components. A wide common-mode input range (WCMIR) SAR ADC processes the differential signals, ensuring accurate analog-to-digital conversion. The DCM eliminates the need for DC cancelation loops, simplifying the design and reducing power consumption. Implemented in a 0.18 µm CMOS process, the system occupies only 0.30 mm, making it suitable for multi-channel applications. The system achieves over 60 dB DC dynamic range and consumes only 9.6 µW, demonstrating its efficiency for portable devices. The simulation results validate its ability to process PPG signals across various conditions, offering a scalable solution for advanced biomedical sensing platforms.
本文介绍了一种为可穿戴健康监测设计的低功耗光电容积脉搏波描记法（PPG）读出系统。该系统采用差分电流镜（DCM）将单端PPG电流转换为差分电压，固有地抑制直流分量。宽共模输入范围（WCMIR）逐次逼近寄存器型模数转换器（SAR ADC）处理差分信号，确保精确的模数转换。DCM消除了对直流消除环路的需求，简化了设计并降低了功耗。该系统采用0.18 µm互补金属氧化物半导体（CMOS）工艺实现，仅占用0.30平方毫米的面积，适用于多通道应用。该系统实现了超过60 dB的直流动态范围，且仅消耗9.6微瓦的功率，证明了其在便携式设备中的高效性。仿真结果验证了其在各种条件下处理PPG信号的能力，为先进的生物医学传感平台提供了可扩展的解决方案。
