TI AFE450生物阻抗分析和电与光学生物传感AFE解决方案

TI公司的AFE450是支持三个信号链的多功能信号采集系统.一个阻抗测量信号链和集成的激励和检测能用在诸如生物阻抗分析(BIA),皮电性质分析(EDA)和阻抗学阻抗谱的应用.有右腿驱动(RLD)的ECG接收器能从和生物阻抗测量共享的一对电极收集单导ECG心电监测装置信号.PPG信号链由用于LED的电流驱动器和从PD检测信号的接收器组成.三个信号链的输出由共同ADC数字化,并存储在FIFO,它可以采用SPI或I2V接口来读出.ECG信号链单导ECG信号采集高达2kHz,INA增益从2-21编程,输入噪音(0.5-150 Hz)在1kHz时为0.75 μVrms, ± 0.6 V差分DC失调和± 0.3 V CM范围, >1 GΩ 输入阻抗, CMRR > 100 dB,HPF具有0.4Hz拐点,快速饱和恢复,集成了300Hz抗混淆低通滤波器,AC,DC引出线检测从1.6-nA 到100-nA.PPG信号链支持高达24PPG信号的收集,支持不同数据速率的光电血管容积图(PPG)传感器,光环回SNR为100dB,采用片上滤波可扩展到110dB,低功耗工作,一个LED为15-μA,接收器为15-μA.PPG发送器具有8位可编LED电流,从25mA到250mA,支持共阳极的8个LED,而PPG接收器支持4个PD,两个并行接收通路,噪音滤波具有可编带宽,跨阻抗增益从3.7 kΩ到1 MΩ,支持外部时钟和内部振荡器模式,自动环境和LED DC消除.主要用在可穿戴设备的Bio-Z, ECG, PPG, EDA, BP,阻抗频谱,带身体组分的称重仪,电流电压和阻抗检测.本文介绍了AFE450主要特性,简化电路图以及评估板AFE4500 EVM主要特性,框图和电路图,材料清单和PCB布局图.

The AFE4500 is a versatile signal acquisition systemthat supports three signal chains. An impedancemeasurement signal chain with integrated excitationand sense can be used for applications like Bioimpedanceanalysis (BIA), Electro-dermal analysis(EDA) and Impedance spectroscopy.

An ECG receiver with a Right-leg drive (RLD) can enable acquisition of a single-lead ECG from a pair ofelectrodes shared with the Bio-impedance measurement. A PPG signal chain comprises of a current driver forLEDs and a receiver that senses the signal from PDs. The outputs of the three signal chains are digitized by acommon ADC and stored in a FIFO which can be read out using an SPI or I2C interface.

AFE450主要特性:

• Integrated signal chains for Bio-Z, EDA, ECG,PPG

• Synchro...