一种10位200kS/s 65nm CMOS SAR ADC IP核  

A 10-bit 200kS/s 65nm CMOS SAR ADC IP Core

作　　者：杨银堂[1,2] 佟星元[1] 朱樟明[1] 管旭光[1] 

机构地区：[1]西安电子科技大学微电子所,西安710071 [2]西安电子科技大学宽禁带半导体材料与器件教育部重点实验室,西安710071

出　　处：《电子与信息学报》2010年第12期2993-2998,共6页Journal of Electronics & Information Technology

基　　金：国家自然科学基金(60725415;60971066;60676009;60776034;60803038);国家863计划项目(2009AA01Z258;2009AA01Z260);国家重大科技专项(2009ZX01034-002-001-005)资助课题

摘　　要：该文基于65nm CMOS低漏电工艺,设计了一种用于触摸屏SoC的8通道10位200kS/s逐次逼近寄存器型(Successive Approximation Register,SAR)A/D转换器(Analog-to-Digital Converter,ADC)IP核。在D/A转换电路的设计上,采用"7MSB(Most-Significant-Bit)+3LSB(Least-Significant-Bit)"R-C混合D/A转换方式,有效减小了IP核的面积,并通过采用高位电阻梯复用技术有效减小了系统对电容的匹配性要求。在比较器的设计上,通过采用一种低失调伪差分比较技术,有效降低了输入失调电压。在版图设计上,结合电容阵列对称布局以及电阻梯伪电阻包围的版图设计方法进行设计以提高匹配性能。整个IP核的面积为322μm×267μm。在2.5V模拟电压以及1.2V数字电压下,当采样频率为200kS/s,输入频率为1.03kHz时,测得的无杂散动态范围(Spurious-Free Dynamic Range,SFDR)和有效位数(Effective Number Of Bits,ENOB)分别为68.2dB和9.27,功耗仅为440μW,测试结果表明本文ADC IP核非常适合嵌入式系统的应用。Based on 65 nm CMOS low leakage process, an 8-channel 10-bit 200 kS/s SAR （Successive Approximation Register） ADC （Analog-to-Digital Converter） IP core for touch screen SoC is realized. In the D/A converter design, a ＂7MSB （Most-Significant-Bit）-plus-3LSB （Least-Significant-Bit）＂ R-C hybrid conversion approach is utilized to reduce the area of the converter, and by reusing the MSB resistor string, the matching requirement of the capacitors is alleviated. With a low-offset pseuso-differential comparison approach, the input offset of the comparator is reduced. In the layout design, capacitor array symmetrical layout routing approach and resistor string dummy surrounding method are utilized to improve the matching performance. The area of the IP core is 322 μm×267 μm. This converter operates with a 2.5 V analog supply and a 1.2 V digital supply. With the input frequency of 1.03 kHz at 200 kS/s sampling rate, the SFDR （Spurious-Free Dynamic Range） and ENOB （Effective Number Of Bits） are measured to be 68.2 dB and 9.27 respectively, and the power dissipation is just measured to be 440 μW. The design results prove the applicability of this converter to embedded SoC.

关 键 词：模数转换器(ADC) 逐次逼近寄存器(SAR) 触摸屏SoC CMOS 低功耗 

分 类 号：TN431.2[电子电信—微电子学与固体电子学]