面向便携式微流控芯片的∑△调制器设计

Design of ∑△ Modulation Used for Portable Microfluidic Chip

为满足微流控芯片所采集信号的高精度模数转换需求,提出一种新型20位高精度∑△调制器,其采用四阶单位调制器架构,过采样率为512。为满足微流控芯片在便携式设备上低功耗设计的需求,设计对调制器后三阶积分器共用,即仅采用2组运算放大器便可完成四阶调制功能,大幅降低了A/D转换所需功耗。先通过Simulink对系统进行设计和验证,然后基于TSMC 0.18μm标准CMOS工艺对调制器进行电路实现和仿真。仿真结果显示,提出的调制器结构可实现20.27位有效位数,功耗仅为12.8m W,相比非共用结构下降3.3m W。

A new20-bit high precisionΣΔmodulator is proposed in this paper.It uses a fourth-order unit modulator architecture with an oversampling rate of512.Especially to meet the microfluidic chip in the portable device on the needs of low-power design,the design of the latter third-order integrators-sharing,that is,only two sets of operational amplifiers can complete the fourth-order modulation,significantly reducing the required power consumption of A/D conversion.In this paper,the system is designed and validated by Simulink,and then the circuit is realized and simulated based on TSMC0.18μm standard CMOS process.