一种用于无电池胎压监测系统的低功耗8 bit SAR ADC设计  

A Novel Low-Power 8 bit SAR ADC for Battery-less TPMS SoC

作　　者：王义[1] 乌力吉[1] 张向民[1] 吴行军[1] 方华军[1] 

机构地区：[1]清华大学微电子学研究所,北京100084

出　　处：《微电子学与计算机》2016年第10期91-96,共6页Microelectronics & Computer

摘　　要：在无电池胎压监测系统中,为降低ADC功耗,采用了一种改进的DAC结构并设计实现了一款低功耗8bit SAR ADC.与传统结构中采用Vref作为参考电压相比,设计中DAC采用Vref/2作为参考电压,并实现了（0,Vref）的满量程输入,在DAC的量化中可降低87.5%动态功耗.在完成电路和版图设计后,仿真结果显示,在采样率为2kS/s,电源电压为3V,参考电压为1.5V时,ADC平均动态功耗为0.9μW.MATLAB频谱分析显示,ADC有效位数为7.6bit,无杂散动态范围为63.2dB,工作温度范围为-40~125℃.并已运用于胎压监测SoC中提交0.35μm BCD汽车电子工艺流片.An analog-to-digital converter is used to digitalize the pressure data in Battery-less TPMS （Tire Pressure Monitoring System）. To reduce power consumption, an 8-bit low-power SAR（Successive Approximation Register） ADC, with a modified switching method, is designed after analysis the requirements of the interface of pressure sensor. The DAC switching method uses Vref/2, rather than Vref in conventional way, as the only reference voltage to digitalize the input signals with the amplitude range of （0,Vref）. The proposed design reduces the average power consumption in the DAC by 87.5%during digitization. Post simulation results show that at the power supply of 3 V and reference voltage of 1.5 V and with the sampling rate of 2 kS/s, the average dynamic power is 0.9 μW, and the ADC can digitize the input signal in a full-scale range of 3 V with ENOB of 7.6 bits and SNDR of 63.2 dB. It can work steadily with a temperature range of -40～125℃. The ADC has been applied to the Battery-less TPMS SoC and taped out in a 0. 35μm BCD （Bipolar-CMOS-DMOS） automotive electronic process.

关 键 词：无电池 胎压监测系统 SAR ADC 低功耗 高稳定性 

分 类 号：TN4[电子电信—微电子学与固体电子学]