A Low-Power CMOS Analog Front-End IC with Adjustable On-Chip Filters for Biosensors

• 作者: Donald Y. C. Lie Tam Nguyen Vighnesh Das Weibo Hu Yenting Liu
• 来源期刊: 生物传感器(英文)
• 学科: 医学
• 关键词: LOW-POWER CMOS Bio-Sensor Applications DC-Coupled
• 年，卷（期）: 2013,（4）
• 页码范围: 104-111
• 页数: 8页
• 分类号: R73

摘要

This paper presents a low-power CMOS analog front-end (AFE) IC designed with a selectable on-chip dual AC/DC- coupled paths for bio-sensor applications. The DC-coupled path can be selected to sense a biosignal with useful DC information, and the AC-coupled path can be selected for sensing the AC content of the biosignal by attenuating the unwanted DC component. The AFE IC includes a DC-coupled instrumentation amplifier (INA), two variable-gain 1st-order low pass filters (LPF) with tunable cut-off frequencies, a fixed gain 2nd-order Sallen-Key high-pass filter (HPF) with tunable cut-off frequencies, a buffer and an 8-bit differential successive approximation register (SAR) ADC. The entire AFE channel is designed and fabricated in a proprietary 0.35-μm CMOS technology. Excluding an external buffer needed to properly drive the ADC, the measured AFE IC consumes only 2.37 μA/channel with an input referred noise of ~40 μVrms in [1 Hz, 1 kHz], and successfully displays proper ECG (electrocardiogram) and electrogram (EGM) waveforms for QRS peaks detection. We expect that the low-power dual-path design of this AFE IC can enable it to periodically record both the AC and the DC signals for proper sensing and calibration for various bio-sensing applications.