A Bio-IA With Fast Recovery and Constant Bandwidth for Wearable Bio-Sensors
A Bio-IA With Fast Recovery and Constant Bandwidth for Wearable Bio-Sensors
复制标题
用于可穿戴生物传感器的具有快速恢复和恒定带宽的 Bio-IA
DOI：
10.1109/jsen.2021.3092001
复制
发表时间：
2021-09
影响因子：
4.3
通讯作者：
Wenbin Huang
中科院分区：
文献类型：
--
作者：
Lianxi Liu;Yuyuan Tian;Wenbin Huang
本文提出了一种用于可穿戴生物传感器的具有快速恢复和恒定带宽的生物信号仪表放大器（Bio-IA）。为了缩短Bio-IA的失调校准时间，减少校准过程中生物信号的损失，设计了一种具有快速恢复功能的数控直流伺服环（DCDSL），实现了更大的失调校准范围和更快的校准速度。提出的恒定带宽可编程增益放大器（PGA）采用双偏置伪电阻（PR）来稳定不同增益下的通带宽度，有效地防止了低频信号的丢失。此外，本文还首次对DCDSL的噪声和双偏置PR的噪声进行了分析。所提出的Bio-IA在0.18<inline-formula><tex-math notation="LaTeX">μ m $</tex-math></inline-formula> CMOS工艺中实现，占用<inline-formula><tex-math notation="LaTeX">849 μ m * 451 μ m $</tex-math></inline-formula>的核心面积。测试结果表明，Bio-IA可校准±511 mV的直流偏置，偏置极性突变时的响应时间小于70 ms。当Bio-IA的增益从26到40 dB变化时，其通带宽度保持恒定，高通和低通截止频率分别为0.4 Hz和200 Hz。在0.1-200 Hz范围内，输入参考噪声为<inline-formula><tex-math notation="LaTeX">0.72 μ</tex-math></inline-formula>Vrms。所提出的Bio-IA消耗<inline-formula><tex-math notation="LaTeX">$5.5~\mu \text{W}$</tex-math></inline-formula>从1.2 V的电源电压。
This paper proposes a bio-signal instrumentation amplifier (Bio-IA) with fast recovery and constant bandwidth for wearable bio-sensors. To shorten the offset calibration time of the Bio-IA and reduce the loss of bio-signal in the calibration process, a digital-controlled DC servo loop (DCDSL) with fast recovery is designed, which achieves a larger offset calibration range and a faster calibration speed. The proposed programmable gain amplifier (PGA) with constant bandwidth uses dual-biased pseudo-resistor (PR) to stabilize the passband width under different gains, effectively preventing the loss of low-frequency signals. Besides, this paper analyzes the noise of the DCDSL and the noise of dual-biased PR for the first time. The presented Bio-IA was implemented in a 0.18-<inline-formula> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> CMOS process, occupying a core area of <inline-formula> <tex-math notation="LaTeX">$849 ~\mu {\sf m}\times 451 ~\mu {\sf m}$ </tex-math></inline-formula>. The measured results show that the Bio-IA can calibrate a DC offset of ±511 mV, and the response time is less than 70 ms when the offset polarity changes suddenly. When the gain of the Bio-IA varies from 26 to 40 dB, its passband width remains constant, and the high-pass and low-pass cut-off frequencies are 0.4 Hz and 200 Hz, respectively. The input-referred noise over the range of 0.1-200 Hz is <inline-formula> <tex-math notation="LaTeX">$0.72~\mu $ </tex-math></inline-formula>Vrms. The proposed Bio-IA consumes <inline-formula> <tex-math notation="LaTeX">$5.5~\mu \text{W}$ </tex-math></inline-formula> from 1.2 V supply voltage.