A Low-Power Opamp-Less Second-Order Delta-Sigma Modulator for Bioelectrical Signals in 0.18 μm CMOS

被引：3

作者：

Cardes, Fernando ^{[1
]}

Baladari, Nikhita ^{[1
,2
]}

Lee, Jihyun ^{[1
]}

Hierlemann, Andreas ^{[1
]}

机构：

[1] Dept Biosyst Sci & Engn, ETH Zurich, CH-4058 Basel, Switzerland

[2] Sect Bioelectron, TU Delft, NL-2628 CD Delft, Netherlands

来源：

SENSORS | 2021年 / 21卷 / 19期

基金：

瑞士国家科学基金会; 欧洲研究理事会;

关键词：

ADC; biosensor; CMOS; delta-sigma modulation; neural interface; VCO-ADC; VLSI; MICROELECTRODE ARRAY; ELECTRODES; ADC; BANDWIDTH;

D O I：

10.3390/s21196456

中图分类号：

O65 [分析化学];

学科分类号：

070302 ; 081704 ;

摘要：

This article reports on a compact and low-power CMOS readout circuit for bioelectrical signals based on a second-order delta-sigma modulator. The converter uses a voltage-controlled, oscillator-based quantizer, achieving second-order noise shaping with a single opamp-less integrator and minimal analog circuitry. A prototype has been implemented using 0.18 mu m CMOS technology and includes two different variants of the same modulator topology. The main modulator has been optimized for low-noise, neural-action-potential detection in the 300 Hz-6 kHz band, with an input-referred noise of 5.0 mu V-rms, and occupies an area of 0.0045 mm(2). An alternative configuration features a larger input stage to reduce low-frequency noise, achieving 8.7 mu V-rms in the 1 Hz-10 kHz band, and occupies an area of 0.006 mm(2). The modulator is powered at 1.8 V with an estimated power consumption of 3.5 mu W.

引用

页数：14