A 10-bit 200-kS/s SAR ADC IP core for a touch screen SoC

Based on a 5 MSBs(most-significant-bits)-plus-5 LSBs(least-significant-bits) C-R hybrid D/A conversion and low-offset pseudo-differential comparison approach,with capacitor array axially symmetric layout topology and resistor string low gradient mismatch placement method,an 8-channel 10-bit 200-kS/s SAR ADC(successive-approximation -register analog-to-digital converter) IP core for a touch screen SoC(system-on-chip) is implemented in a 0.18μm 1P5M CMOS logic process.Design considerations for the touch sc...     

一种用于触摸屏SoC的10位200kS/s SAR ADC IP核

采用“5MSBs (Most-Significant-Bits) + 5LSBs (Least-Significant-Bits)”C-R混合式D/A转换方式以及低失调伪差分比较技术,结合电容阵列对称布局以及电阻梯低失配版图设计方法,基于0.18µm 1P5M CMOS Logic工艺,设计实现了一种用于触摸屏SoC (System-on-Chip)的8通道10位200kS/s逐次逼近型A/D转换器IP核。在1.8V电源电压下,测得的微分非线性误差和积分非线性误差分别为0.32LSB和0.81LSB。在采样频率为200kS/s,输入频率为91kHz时,测得的无杂散动态范围(SFDR: Spurious-Free Dynamic Range)和有效位数(ENOB: Effective-Number-of-Bits)分别为63.2dB和9.15bits,功耗仅为136µW。整个A/D转换器IP核的面积约为0.08mm2。设计结果显示该转换器满足触摸屏SoC的应用要求。