A sub-1 V high-precision CMOS bandgap voltage reference

A third-order, sub-1 V bandgap voltage reference design for low-power supply, high-precision applications is presented. This design uses a current-mode compensation technique and temperature-dependent resistor ratio to obtain high-order curvature compensation. The circuit was designed and fabricated by SMIC 0.18 μm CMOS technology. It produces an output reference of 713.6 mV. The temperature coefficient is 3.235 ppm/℃ in the temperature range of -40 to 120 ℃, with a line regulation of 0.199 mV/V when the supply voltage varies from 0.95 to 3 V. The average current consumption of the whole circuit is 49 μA at the supply voltage of 1 V.     

A low-power 10-bit 250-KSPS cyclic ADC with offset and mismatch correction

A low power 10-bit 250-k sample per second(KSPS) cyclic analog to digital converter(ADC) is presented. The ADC’s offset errors are successfully cancelled out through the proper choice of a capacitor switching sequence.The improved redundant signed digit algorithm used in the ADC can tolerate high levels of the comparator’s offset errors and switched capacitor mismatch errors.With this structure,it has the advantages of simple circuit configuration,small chip area and low power dissipation.The cyclic ADC manufactured with the Chartered 0.35μm 2P4M process shows a 58.5 dB signal to noise and distortion ratio and a 9.4 bit effective number of bits at a 250 KSPS sample rate.It dissipates 0.72 mW with a 3.3 V power supply and occupies dimensions of 0.42×0.68 mm~2.     

饮用水中抗生素残留检测方法研究进展

抗生素作为一种杀灭或抑制细菌生长的药物,在食品、临床、兽药、农业等方面得到了广泛的应用。然而抗生素的大量应用导致其残留物进入地表水,进而污染自来水厂水源,而标准的水处理不能将其完全清除,从而对人体产生较大的危害,引起过敏、发热、耐药性甚至再生障碍性贫血等症状。因此,针对饮用水中抗生素残留检测的研究引起了人们广泛的关注。本文对近年来可应用于饮用水中抗生素残留分析方法(高效液相色谱、太赫兹时域光谱技术、免疫分析法、表面增强拉曼光谱法)的研究进展进行了综述,并对今后抗生素残留检测的发展方向作了展望。     

一种二阶曲率补偿带隙基准电压源

利用CMOS工艺中Poly电阻和N-well电阻温度系数的不同,设计了一种输出可调的二阶曲率补偿带隙基准电压源.采用Chartered 0.35μm CMOS工艺模型,使用Cadence工具对电路进行了仿真,结果表明电路在电源电压为1.8V时可正常工作,当其在1.8～3V范围内变化时,基准电压变化仅有3.8mV;工作电压为2V时,输出基准电压在-40°C到80°C的温度范围内温度系数为1.6ppm/°C,工作电流为24μA,低频下的电源抑制比为-47dB.该带隙基准电压源的设计可以满足低温漂、高稳定性、低电源电压以及低功耗的要求.     

带有失配修正的10-bit 250-KSPS低功耗循环ADC设计

本为提出了一种10-bit 250k采样率（KSPS）的循环模数转换器（ADC）。通过适当的选取电容开关时序,ADC的失调误差被有效的消除。改进的冗余有符号数（RSD）法则能够容忍较大的比较器失调误差与开关电容失配误差。通过采用这种结构,ADC具有了电路结构简单、占用芯片面积低以及低功耗的优点。该循环ADC采用Chartered 0.35 um 2P4M工艺制造,在250k的采样率下,其信号对噪声和失真比（SNDR）为58.5dB,有效位数（ENOB）为9.4bit。该电路在3.3V的电源电压下,功耗为0.72mW,占有芯片面积0.42×0.68 mm2。     

低功耗高精度的电压比较器设计

设计了一款用于实现10位精度逐次逼近型模数转换器(SAR ADC)的电压比较器,该比较器采用高速高精度比较器结构并进行了优化,在高速度、低功耗锁存器的基础上加预放大级以提高比较精度,加RS触发器优化处理比较器的输出信号。同时,采用失调校准技术消除失调,预放大级采用共源共栅结构抑制回程噪声,最终获得了高精度和较低的功耗。仿真结果表明:在Chartered 0.35μm 2P4MCMOS工艺下,时钟频率5 MHz,电源电压3.3 V,分辨率达0.1 mV,平均功耗约为0.45 mW,芯片测试结果表明比较器满足了SAR ADC的要求。