一种带分段随机温度计码的10位电流舵数模转换器

A 10-bit Current-steering DAC with Segmented Randomized Thermometer-coding

介绍了一种基于分段随机温度计码的动态匹配算法。该算法可以有效抑制电流源失配造成的谐波失真,因此可以降低对电流源匹配的需求。在此算法基础上,针对芯片面积,优化了电流源尺寸选取与分段位数的选择。在SMIC 0.13μm CMOS工艺中实现了一款10位电流舵数模转换器(Digial-to-analog converter,DAC),单通道的面积为0.05mm2。测试结果显示,微分非线性(Differential non-linearity,DNL)与积分非线性(Integral nonlinearity,INL)分别为0.58LSB和0.56LSB,无杂散动态范围(Spurious free dynamic range,SFDR)最高可达80dBc。单通道DAC在1.2V数字/模拟电源电压下整体功耗小于3mW。

A dynamic element matching （DEM） algorithm based on Segmented Randomized Thermometer-Coding （SRTC） is presented. This algorithm can suppress the harmonic distortion caused by current source mismatching, thus relieving the matching requirements. Segmentation bits and current source dimension are optimized to minimize the chip area. A 10-bit current-steer- ing DAC is implemented in SMIC 0.13 /~m CMOS process with the proposed method. Each chan- nel of the proposed DAC occupies less than 0.05 mmz. The measured differential non-linearity （DNL） and integral non-linearity （INL） are 0.58 LSB and 0.56 LSB respectively, and the meas- ured peak spurious-free dynamic range （SFDR） is 80 dBc. It consumes a total of less than 3 mW from 1.2 V digital/analog supply.