IEEE Trans Biomed Circuits Syst. 2007 Mar;1(1):63-72. doi: 10.1109/TBCAS.2007.893176.
A 16-channel current-measuring very large-scale integration (VLSI) sensor array system for highly sensitive electrochemical detection of electroactive neurotransmiters like dopamine and nitric-oxide is presented. Each channel embeds a current integrating potentiostat within a switched-capacitor first-order single-bit delta-sigma modulator implementing an incremental analog-to-digital converter. The duty-cycle modulation of current feedback in the delta-sigma loop together with variable oversampling ratio provide a programmable digital range selection of the input current spanning over six orders of magnitude from picoamperes to microamperes. The array offers 100-fA input current sensitivity at 3.4-muW power consumption per channel. The operation of the 3 mm times3 mm chip fabricated in 0.5-mum CMOS technology is demonstrated with real-time multichannel acquisition of neurotransmitter concentration.
提出了一种用于高灵敏度电化学检测神经递质（如多巴胺和一氧化氮）的 16 通道电流测量超大规模集成（VLSI）传感器阵列系统。每个通道在开关电容一阶单比特 delta-sigma 调制器中嵌入一个电流积分恒流源，实现增量模数转换器。delta-sigma 环中的电流反馈占空比调制以及可变过采样比提供了可编程的数字输入电流范围选择，可跨越六个数量级，从皮安到微安。该阵列在每个通道 3.4 微瓦的功耗下提供 100 飞安的输入电流灵敏度。该 3mm×3mm 的芯片采用 0.5 微米 CMOS 技术制造，其实时多通道神经递质浓度采集演示了其操作。
