A CMOS voltage reference, which is based on VGs and/x ΔGS in the weak inversion region, has been designed and implemented in standard 0.6μm CMOS technology. No diodes and parasitic bipolar junction transistors （BJT...A CMOS voltage reference, which is based on VGs and/x ΔGS in the weak inversion region, has been designed and implemented in standard 0.6μm CMOS technology. No diodes and parasitic bipolar junction transistors （BJTs） are used. The proposed voltage reference uses a current-mode topology by summing a PTAT current and a CTAT current into a re- sistor to generate the required reference voltage. It can also provide more than one reference voltage output, which is quite suitable for systems requiring many different reference voltages simultaneously. The occupied chip area is 0. 023mm^-2 . The operation supply voltage is from 2.5 to 6V, and the maximum supply current is 8.25μA. The designed three different out- puts are respectively about 203mV, 1.0V, and 2.05V at room temperature when the supply voltage is 4V. The circuit achieves a temperature coefficient of 31ppm/℃ in the temperature range of 0 to 100℃ and an average line regulation of ± 0. 203%/V. The voltage reference has been successfully applied in a white LED backlight driver chip.展开更多
A new temperature compensation technique for ring-oscillator-based ADCs is proposed. This technique employs a novelcfixed-number-based algorithm and CTAT current biasing technology to compensate the temperature-depend...A new temperature compensation technique for ring-oscillator-based ADCs is proposed. This technique employs a novelcfixed-number-based algorithm and CTAT current biasing technology to compensate the temperature-dependent variations of the output, thus eliminating the need for digital calibrations. Simulation results prove that, with the proposed technique,the resolution in the temperature range of 0 to 100℃ can reach a 2mV quantization bin size with an input voltage span of 120mV at the sampling frequency of fs = 100kHz.展开更多
文摘智能导师系统(Intelligent Tutor System,ITS)在教学中具有自适应性,但是目前大多数的ITS实现技术复杂,且与浏览器的兼容性差。文章首先介绍了认知导师创作工具(The Cognitive Tutor Authoring Tools,CTAT)的分类、构成及工作环境,构建了基于CTAT的智能导师系统;随后,分析了CTAT与大规模开放在线课程(Massive Open Online Courses,MOOC)平台的集成过程;最后,通过基于CTAT的智能导师系统在"Big Data in Education"MOOC课程中的具体应用,论证了CTAT与MOOC平台集成的可行性。文章的研究表明:在MOOC中嵌入ITS,能有效提升学习者"做中学"的积极性,并提高自主学习的效率。
文摘A CMOS voltage reference, which is based on VGs and/x ΔGS in the weak inversion region, has been designed and implemented in standard 0.6μm CMOS technology. No diodes and parasitic bipolar junction transistors （BJTs） are used. The proposed voltage reference uses a current-mode topology by summing a PTAT current and a CTAT current into a re- sistor to generate the required reference voltage. It can also provide more than one reference voltage output, which is quite suitable for systems requiring many different reference voltages simultaneously. The occupied chip area is 0. 023mm^-2 . The operation supply voltage is from 2.5 to 6V, and the maximum supply current is 8.25μA. The designed three different out- puts are respectively about 203mV, 1.0V, and 2.05V at room temperature when the supply voltage is 4V. The circuit achieves a temperature coefficient of 31ppm/℃ in the temperature range of 0 to 100℃ and an average line regulation of ± 0. 203%/V. The voltage reference has been successfully applied in a white LED backlight driver chip.
文摘A new temperature compensation technique for ring-oscillator-based ADCs is proposed. This technique employs a novelcfixed-number-based algorithm and CTAT current biasing technology to compensate the temperature-dependent variations of the output, thus eliminating the need for digital calibrations. Simulation results prove that, with the proposed technique,the resolution in the temperature range of 0 to 100℃ can reach a 2mV quantization bin size with an input voltage span of 120mV at the sampling frequency of fs = 100kHz.
