基于电流镜的电化学CMOS恒电位仪的设计

摘要

A CMOS potentiostat based on three-electrode amperometric chemical sensor is designed. The circuit is formed by the control amplifier, current-mirror and the single-ended OTA. Compared with the traditional design, this structure has several advantages, for example the power consumption is lower, the layout area is smaller and the range of sensing current is wider. Simulation is carried out with 0.5 μm CMOS process by Spectre emulator,the current-sensing range is from 20 pA～20 μA. Dynamic range is 120 dB.%设计了一种基于电流镜的三电极电化学传感器CMOS恒电位仪电路,由控制运放、电流镜和单端输出的跨导放大器构成.与传统的恒电位仪相比,该电路结构简单,减少了读出电路的功耗和版图面积,具有较宽的动态范围.在CSMC 0.5μm 2PTM CMOS工艺下,用Spectre仿真器对电路进行了模拟,仿真结果表明:传感电流范围为20pA-20μA,动态范围可达120dB.