A 16-bit 1 MSPS SAR ADC with foreground calibration and residual voltage shift strategy

In this paper, a 16-bit 1MSPS foreground calibration successive approximation register analog-to-digital converter (SAR ADC) is developed by the CMOS 0.25 μm process. An on-chip all-digital foreground weights calibration technique integrating self-calibration weight measurement with PN port auto-balance technique is designed to improve the performance and lower the costs of the developed SAR ADC. The SAR ADC has a chip area of 2.7 × 2.4 mm², and consumes only 100 μW at the 2.5 V supply voltage with 100 KSPS. The INL and DNL are both less than 0.5 LSB.     

A single-chip adaptive delta modulator with optimum performance

This paper describes the design of a high performance Si-Gate CMOS LSI circuit for an Adaptive Delta Modulation System (ADM). The circuit design is based on 4 μ design rules. The size of the die is approximately 25 mm² and the circuit operates synchronously under the control of an 8 MHz two phase non-overlapping clock. A fault tolerant scheme is used at the comparator section for reliability improvement purposes. The adaptation logic of the system is based on the algorithm introduced in [2] where a rigorous proof is provided for showing the optimality of the algorithm in terms of performance. This paper demonstrates the feasibility of implementing this algorithm with a single chip adaptive delta modulator.     

井下短路电流幅相保护及实现方式

建立了三相对称短路电流与相角的关系，给出了确定幅相保护特性的新方法，提出了相行的幅相保护的实现方式。     

一种用于峰值电流模式的锁存比较器设计

设计了一种宽输入共模范围的比较器,用以处理高端电流检测中大共模信号的问题。通过采用预放大器和锁存器结构,优化了传输延时,提高了电路的分辨率及工作速度。基于0.5μm工艺,采用Cadence软件对电路进行仿真。结果表明,该电路可以处理轨到轨的共模输入电平,其最大可处理共模输入电平可跟随输入电压变化。当开关电源频率为1 MHz时,比较器电路的分辨率达到0.1 mV。     

工作时钟1GHz超高速电压比较器设计

超高速模数转换电路是现代高速通信和信号处理电路中的重要组成部分,而超高速比较器的设计是超高速模数转换器设计中的关键环节.文中通过综合考虑比较器的传输延时和失调电压等因素,讨论了超高速比较器的设计方法,并在基于1.8V电源电压、TSMC0.18μm CMOS工艺下设计了一个工作时钟为1GHz的超高速电压比较器,经过芯片测试,证明该比较器可以在1GHz时钟下稳定工作,失调电压仅为70μV.该比较器可以用于超高速模数/数模转换器的设计.     

一种采用PVT不敏感电荷传输电路的27mW 10位125MSPS 电荷域流水线模数转换器

A low power 10-bit 125-MSPS charge-domain(CD) pipelined analog-to-digital converter(ADC) based on MOS bucket-brigade devices(BBDs) is presented.A PVT insensitive boosted charge transfer(BCT) that is able to reject the charge error induced by PVT variations is proposed.With the proposed BCT,the common mode charge control circuit can be eliminated in the CD pipelined ADC and the system complexity is reduced remarkably.The prototype ADC based on the proposed BCT is realized in a 0.18μm CMOS process,with power consumption of only 27 mW at 1.8-V supply and active die area of 1.04 mm~2.The prototype ADC achieves a spurious free dynamic range(SFDR) of 67.7 dB,a signal-to-noise ratio(SNDR) of 57.3 dB,and an effective number of bits(ENOB) of 9.0 for a 3.79 MHz input at full sampling rate.The measured differential nonlinearity(DNL) and integral nonlinearity (INL) are +0.5/-0.3 LSB and +0.7/-0.55 LSB,respectively.     

基于InP-DHBT的20 GHz的超高速比较器

采用截止频率fT为170 GHz的InP-DHBT工艺,我们设计并制作了一个超高速主从电压比较器。整个芯片的面积（包括焊盘）是0.75?1.04 mm2,在-4V的单电源电压下消耗的功耗是440mW（不包括时钟产生部分）。整个芯片包含了77个InP DHBTs。比较器的尼奎斯特测试到了20GHz,输入灵敏度在10 GHz采样率的时候是6mV,在20 GHz的时候是16 mV。据我们所知,这在国内还是第一次在单片上集成超过70个InP DHBTs的电路,也是目前国内具有最高采样率的比较器。     

Uncertainty reducing method for the reference standards in gauge block comparator calibration

A simple method for reducing the uncertainty of reference standards has been proposed for gauge block comparator calibration. Errors due to the reference value of the length difference for mechanical comparator evaluation can be reduced by using the average of two reference values. Two reference values of length difference are obtained by the appropriate combination of three gauge blocks. Errors caused by reference gauges are canceled and averaged. An error reduction effect was successfully demonstrated using an actual mechanical comparator.     

Perspectives of atmospheric reference leaks calibration by gravimetric method

The measurement of freon (mainly R134a) leaks is an important task of metrology. The paper deals with the study of the possibilities of improvement of gravimetric traceability method for the permeation secondary standards of atmospheric freon leaks. Their leak rates are different under atmospheric and vacuum conditions; only the first one is interesting for practical use. Moreover, the desirable steady state after changing the conditions is achieved only after certain relaxation time. This complicates the correction of the buoyancy influence, which causes the uncertainty increase. The leak rates of a typical secondary standard of this kind under atmospheric and vacuum conditions are compared, the needed relaxation times searched and some possibilities of further improvement discussed.     

一种高速高精度CMOS电流比较器

针对传统电流比较器速度慢,精度低等问题,提出了一种新型CMOS电流比较器电路。我们采用CMOS工艺HSPICE模型参数对该电流比较器的性能进行了仿真,结果表明当电源电压为3V,输入方波电流幅度为0．3uA时,电流比较器的延时为5．2ns,而其最小分辨率仅约为0．8nA。该比较器结构简单,速度快,精度高,适合应用于高速高精度电流型集成电路中。