基于微测辐射热计读出电路的DAC设计  

DAC Designed for Readout Circuit of Microbolometers

作　　者：蔡泓[1] 唐祯安[1] 谢冬雪 黄伟奇 CAI Hong;TANG Zhen-an;XIE Dong-xue;HUANG Wei-qi(Electronic Science and Technology Institute,Dalian University of Technology,Dalian 116023,China)

机构地区：[1]大连理工大学电子科学与技术学院,辽宁大连116023

出　　处：《仪表技术与传感器》2018年第8期17-20,24,共5页Instrument Technique and Sensor

基　　金：国家自然科学基金重点项目(NO.61131004);国家自然科学基金项目(NO.61274076)

摘　　要：微测辐射热计受制作材料、工艺等因素的影响存在较大的不均匀性,导致探测信号失真。基于CSMC 0.18μm Mix Singal RF 1P6M工艺设计了一个10位精度的R-2R倒梯形电阻网络数模转换器(DAC),为微测辐射热计读出电路提供可调节的偏置电压,补偿焦平面阵列的非均匀性,提高成像质量。电路仿真结果显示,在3.3 V电源电压下,DAC满量程功耗小于2 m W。当采样频率为2 MHz、输入频率为5.86 k Hz时,无杂散动态范围为75.9 d B。微分非线性误差小于0.32 LSB,积分非线性误差小于0.21 LSB。The nonuniformity in the microbolometer due to factors such as materials and processing technologies leads to the anamorphose of the detecting signals.Based on the CSMC 0.18μm Mix Singal RF 1P6M process,an R-2R trapezoidal resistance network DAC(DAC)was designed,providing an adjustable bias voltage for a microbolometer readout circuit to compensate for nonuniformity of focal plane arrays and to improve imaging quality.The circuit simulation results show that power consumption in a full scale of the DAC is less than 2 mW at the 3.3 V supply voltage.When the sampling frequency achieves 2 MHz and the input frequency equals 5.86 kHz,the spurious free dynamic range is 75.9 dB.The differential nonlinear error is less than 0.32 LSB,while the integral nonlinear error is less than 0.21 LSB.

关 键 词：微测辐射热计 读出电路 非均匀性 R-2R倒梯形电阻网络DAC 

分 类 号：TN432[电子电信—微电子学与固体电子学]