Design of a CMOS potentiostat circuit for electrochemical detector arrays
Design of a CMOS potentiostat circuit for electrochemical detector arrays
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DOI：
10.1109/tcsi.2006.888777
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发表时间：
2007-04-01
影响因子：
5.1
通讯作者：
Minch, Bradley A.
中科院分区：
文献类型：
--
作者：
Ayers, Sunitha;Gillis, Kevin D.;Minch, Bradley A.
高通量电极阵列是用于测试药物对细胞功能的影响的先进设备所必需的。在本文中，我们提出了恒电位仪电路的设计标准，该电路能够测量亚毫秒时间分辨率和皮安电流分辨率的电极表面的瞬态安培氧化电流。恒电位仪是一个调节的共源共栅级，其中高增益放大器通过负反馈回路保持电极电压。恒电位仪使用一种新的共享放大器结构，其中给定行检测器中的所有放大器共享一个公共半电路，从而允许我们每个检测器使用更少的晶体管。我们还提出了测量从一个测试芯片，在0.5 μ m，5-V CMOS工艺通过MOSIS制造。每个探测器占用35 μ m × 15 μ m的布局面积，包含8个晶体管和一个50 fF的积分电容器。2 kHz带宽下的均方根电流噪声约为110 fA。在2 kHz时的最大电荷存储容量为1.26 x 10（6）个电子。
High-throughput electrode arrays are required for advancing devices for testing the effect of drugs on cellular function. In this paper, we present design criteria for a potentiostat circuit that is capable of measuring transient amperometric oxidation currents at the surface of an electrode with submillisecond time resolution and picoampere current resolution. The potentiostat is a regulated cascode stage in which a high-gain amplifier maintains the electrode voltage through a negative feedback loop. The potentiostat uses a new shared amplifier structure in which all of the amplifiers in a given row of detectors share a common half circuit permitting us to use fewer transistors per detector. We also present measurements from a test chip that was fabricated in a 0.5-mu m, 5-V CMOS process through MOSIS. Each detector occupied a layout area of 35 mu m x 15 mu m and contained eight transistors and a 50-fF integrating capacitor. The rms current noise at 2-kHz bandwidth is approximate to 110 fA. The maximum charge storage capacity at 2 kHz is 1.26 x 10(6) electrons.