一种用于磁传感器读出电路的双斜率ADC  

A Dual-Slope ADC for Read-out Circuit of Magnetic Sensor

作　　者：张任伟[1] 刘珂[1] 杜占坤[1] 阎跃鹏[1] 

机构地区：[1]中国科学院微电子技术研究所,北京100029

出　　处：《微电子学与计算机》2015年第3期11-14,共4页Microelectronics & Computer

基　　金：国家自然科学基金项目(61204034)

摘　　要：基于集成片上双斜率ADC结构简单,适用于低频小信号的转换的特点.提出了一种适合于磁场传感器读出电路的可编程双斜率ADC,能够将磁传感器输出的低频模拟小信号转换为高精度的数字信号.针对不同的应用对于转换时间和转换精度的不同要求,可对ADC的精度进行编程配置,有利于提高电路的工作效率.ADC的积分器部分采用差分型开关电容结构以减小芯片面积,并且对积分方式进行了改进,通过叠加积分增加正积分的积分斜率来提高ADC的有效位数.仿真结果显示,ADC的有效位数为11.96bit,在3.3V工作电压下,功耗仅为1.55mW,满足磁传感器小信号读出电路的要求.The Dual-Slope ADC integrated on chip with has a simple configuration and is suitable to small signal conversion with a low frequency.Based on these characteristics,aprogrammable Dual-Slope ADC is proposed to convert analog small signal of Magnetic Sensor to digital signal with high-precision.The conversion time and accuracy can be changed freely by different requirement in different application and the resolution of ADC can be programmed,which is beneficial for improving efficiency.In the work,a difference switched-capacitor integrator is used to decrease the area of chip.Besides,the method of integral has been improved.The slope of positive integral can be increased by multiplicity-integral,so the precision of transfer would be raised.Finally,the result of simulation show that the ADC proposed in this paper has a ENOD of 11.96 bits and the power consumption with a 3.3Vsupply is only 1.55 mW,which is suitable to detect the small signal output by magnetic sensor in read-out circuit.

关 键 词：双斜率ADC 可编程 开关电容 叠加积分 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]