CMOS数字电路抗热载流子研究

介绍了热载流子效应与电路拓扑结构及器件参数之间的关系,并在此基础上提出了基本逻辑门的一些搞热载流子加固方法。通过可靠性模拟软件验证这些方法,为CMOS数字电路提高抗热载流子能力提供了参考。     

基于时序逻辑的测试系统的设计与实现

为对某系统工作状态中的重要性能参数进行全程监测和定量分析,并满足在高冲击等特殊环境下使用的要求,提出了一种基于FPGA以及Flash介质的测试存储系统设计方案。详细阐述了硬件系统各组成模块的电路及其工作原理,给出了系统内部数字电路的时序逻辑,介绍了采集中的编码方法和提高存储速度的方法。在实际工作过程中,测试系统达到了准确、可靠的记录技术要求,记录下的数据为器件的工作状态分析提供了详实的依据。     

低电压SRAM测试电路设计与实现

本文基于SMIC 40nm LL CMOS工艺对一款256Kb的低电压8T SRAM芯片进行测试电路设计与实现,重点研究低电压SRAM的故障模型和测试算法,并完成仿真验证与分析。电路主要包括DFT电路和内建自测试电路两部分,前者针对稳定性故障有着良好的覆盖率,后者在传统March C+算法基础上,提出了一种新的测试算法,March-Like算法,该算法能够实现更高的故障覆盖率。仿真结果表明,本文设计的DFT电路能够减小稳定性故障的最小可检测电阻,提高了稳定性故障的测试灵敏度;March-Like算法可以检测到低电压SRAM阵列中的写破坏耦合故障、读破坏耦合故障和写干扰故障。     

近阈值标准单元库和其在传感网芯片中的应用

将电源电压降低到晶体管阈值电压附近可以有效提高数字电路的能效,而近阈值标准单元库是近阈值数字电路设计的基础.通过分析逻辑门间静态噪声容限的兼容性、逻辑门在宽电压范围下延时变化情况,并通过求解最大包问题等的相关算法,对现有的商用数字CMOS标准单元库进行有效筛选,得到适用于低电压工作的近阈值数字CMOS标准单元库.通过一个应用于传感网中的双电压域、双核微控制器流片测试,对此标准单元库进行了验证,结果显示其中工作在0.5V下的高能效核的能量效率相较传统工作电压下提高到2.76倍.     

基于JESD204B的接收端数据链路层设计与实现

行业新标准JESD204B支持高达12.5 Gbit/s串行传输速率,是解决数据转换器与逻辑器件之间高速数据传输问题的主流接口。采用四字节并行处理方案实现了JESD204B协议接收端数据链路层电路,完成协议功能的同时将电路工作时钟频率由1.25 GHz降低到312.5 MHz,使其能在CMOS工艺下使用标准数字电路设计流程实现。将Verilog HDL实现的电路与XILINX JESD204B 6.1v版本的发送端IP核进行对接,验证了该方案的可行性。在Design Compiler平台上,采用65 nm LP CMOS工艺数字标准单元库,对设计方案进行了综合评估。实验结果表明,该方案在工作频率和功能方面均能满足JESD204B协议规范。     

基于RTD与CMOS的新型数字电路设计

纳米电子器件RTD与CMOS电路结合,这种新型电路不仅保持了CMOS动态电路的所有优点,而且在工作速度、功耗、集成度以及电路噪声免疫性方面都得到了不同程度的改善和提高。文中对数字电路中比较典型的可编程逻辑门、全加器电路进行了设计与模拟,并在此基础上对4×4阵列纳米流水线乘法器进行了结构设计。同时讨论了在目前硅基RTD器件较低的PVCR值情况下实现相应电路的可行性。     

一种测试SRAM失效的新型March算法

随着工艺偏差的日益增加,新的失效机制也在亚100 nm工艺的CMOS电路里出现了,特别是SRAM单元。SRAM单元的故障由晶体管阈值电压Vt差异引起,而Vt差异又是由工艺偏差造成的。对于这类SRAM失效机制,需要把它映射成逻辑故障模型,并为检测出这类故障研究出新的March测试序列。针对这些逻辑故障模型,提出了一种新型的March算法序列;并通过验证,得到了很高的测试覆盖率。     

GaAs pHEMT与Si CMOS异质集成的研究

基于圆片级外延层转移技术,将完成GaAs pHEMT有源器件加工的外延层从原有衬底上完整地剥离下来并转移到完成工艺加工的Si CMOS圆片上,基于开发的异类器件互联以及异类器件单片集成电路设计等一系列关键技术,进行了GaAs pHEMT与Si CMOS异质集成单片电路的工艺加工。研制的GaAs pHEMT与Si CMOS异质集成单片数字控制开关电路与传统的GaAs pHEMT单片电路相比,芯片面积减小15%。     

自制逻辑笔、信号发生器

<正> 本文介绍的逻辑笔、信号发生器合二为一,体积小、电路简单、所需器件少,非常适合数字电路的测试。 电路原理 图1为电路原理图。由图可知,整机只用一片89C2051单     

HDMI接口编解码传输模块ASIC设计

在分析HDMI协议的基础上,提出了一种实现HDMI接口传输模块的ASIC设计方案。在Quartus II 10.0平台下,利用可综合的Verilog语言完成了电路的设计综合,并下载到FPGA开发板进行了测试验证。验证结果表明,设计满足HDMI接口传输模块要求,占用逻辑资源少,可应用到总体设计中。     

Level-shifter free design of low power dual supply voltage CMOS circuits using dual threshold voltages

Usage of dual supply voltages in a digital circuit is an effective way of reducing the dynamic power consumption due to the quadratic relation of supply voltage to dynamic power consumption. But the need for level shifters when a low voltage gate drives a high voltage gate has been a limiting factor preventing widespread usage of dual supply voltages in digital circuit design. The overhead of level shifters forces designers to increase the granularity of dual voltage assignment, reducing the maximum obtainable savings. We propose a method of incorporating voltage level conversion into regular CMOS gates by using a second threshold voltage. Proposed level shifter design makes it possible to apply dual supply voltages at gate level granularity with much less overhead compared to traditional level shifters. We modify the threshold voltage of the high voltage gates that are driven by low voltage gates in order to obtain the level shifting operation together with the logic operation. Using our method, we obtained an average of 20% energy savings for ISCAS'85 benchmark circuits designed using 180-nm technology and 17% when 70-nm technology is used.     

A sub-2.0 V BiCMOS logic circuit with a BiCMOS charge pump

A BiCMOS logic circuit with very small input capacitance has been developed, which operates at low supply voltages. A High-beta BiCMOS (Hβ-BiCMOS) gate circuit which fully utilizes the bipolar transistor features achieves 10 times the speed of a CMOS gate circuit with the same input capacitance and operating at 3.3 V supply voltage. In order to lower the minimum supply voltage of Hβ-BiCMOS, a BiCMOS circuit configuration using a charge pump to pull up the output high level of the BiCMOS gate circuit is proposed. By introducing a BiCMOS charge pump, Hβ-BiCMOS achieves very high speed operation at sub-2.0 V supply voltage. It has also been demonstrated that only a very small number of charge pump circuits are required to drive a large number of Hβ-BiCMOS gate circuits     

Bootstrapped full-swing BiCMOS/BiNMOS logic circuits for 1.2-3.3 Vsupply voltage regime

Novel full-swing BiCMOS/BiNMOS logic circuits using bootstrapping in the pull-up section for low supply voltage down to 1 V are reported. These circuit configurations use noncomplementary BiCMOS technology. Simulations have shown that they outperform other BiCMOS circuits at low supply voltage using 0.35 μm BiCMOS process. The delay and power dissipation of several NAND configurations have been compared. The new circuits offer delay reduction between 40 and 66% over CMOS in the range 1.2-3.3 V supply voltage. The minimum fanout at which the new circuits outperform CMOS gate is 5, which is lower than that of other gates particularly for sub-2.5 V operation     

A 1.5-V full-swing BiCMOS logic circuit

A BiCMOS logic circuit applicable to sub-2-V digital circuits has been developed. A transiently saturated full-swing BiCMOS (TS-FS-BiCMOS) logic circuit operates twice as fast as CMOS at 1.5-V supply. A newly developed transient-saturation technique, with which bipolar transistors saturate only during switching periods, is the key to sub-2-V operation because a high-speed full-swing operation is achieved to remove the voltage loss due to the base-emitter turn-on voltage. Both small load dependence and small fan-in dependence of gate delay time are attained with this technique. A two-input gate fabricated with 0.3-μm BiCMOS technology verifies the performance advantage of TS-FS-BiCMOS over other BiCMOS circuits and CMOS at sub 2-V supply     

2.5-V bipolar/CMOS circuits for 0.25-μm BiCMOS technology

An ECL circuit with an active pull-down device, operated from a CMOS supply voltage, is described as a high-speed digital circuit for a 0.25-μm BiCMOS technology. A pair of ECL/CMOS level converters with built-in logic capability is presented for effective intermixing of ECL with CMOS circuits. Using a 2.5-V supply and a reduced-swing BiNMOS buffer, the ECL circuit has reduced power dissipation, while still providing good speed. A design example shows the implementation of complex logic by emitter and collector dottings and the selective use of ECL circuits to achieve high performance     

Subthreshold Source-Coupled Logic Circuits for Ultra-Low-Power Applications

This paper presents a novel approach for implementing ultra-low-power digital components and systems using source-coupled logic (SCL) circuit topology, operating in weak inversion (subthreshold) regime. Minimum size pMOS transistors with shorted drain-substrate contacts are used as gate-controlled, very high resistivity load devices. Based on the proposed approach, the power consumption and the operation frequency of logic circuits can be scaled down linearly by changing the tail bias current of SCL gates over a very wide range spanning several orders of magnitude, which is not achievable in subthreshold CMOS circuits. Measurements in conventional 0.18 m CMOS technology show that the tail bias current of each gate can be set as low as 10 pA, with a supply voltage of 300 mV, resulting in a power-delay product of less than 1 fJ. Fundamental circuits such as ring oscillators and frequency dividers, as well as more complex digital blocks such as parallel multipliers designed by using the STSCL topology have been experimentally characterized.     

A minimum total power methodology for projecting limits on CMOS GSI

A circuit design methodology minimizing total power drain of a static complementary metal-oxide-semiconductor (CMOS) random logic network for a prescribed performance, operating temperature range, and short channel threshold voltage rolloff is investigated. Physical, continuous, smooth, and compact “transregional” MOSFET drain current models that consider high-field effects in scaled devices and permit tradeoffs between saturation drive current and subthreshold leakage current are employed to model CMOS circuit performance and power dissipation at low voltages. Transregional models are used in conjunction with physical short channel MOSFET threshold voltage rolloff models and stochastic interconnect distributions to project optimal supply voltages, threshold voltages, and device channel widths minimizing total power dissipated by CMOS logic circuits for each National Technology Roadmap for Semiconductors (NTRS) technology generation. Optimum supply voltage, corresponding to minimum total power dissipation, is projected to scale to 510 mV for the 50-nm 10-GHz CMOS generation in the year 2012. Techniques exploiting datapath parallelism to further scale the supply voltage are shown to offer decreasing reductions in power dissipation with technology scaling     

Low‐Voltage Current‐Sensing CMOS Interface Circuit for Piezo‐Resistive Pressure Sensor

A new low‐voltage CMOS interface circuit with digital output for piezo‐resistive transducer is proposed. An input current sensing configuration is used to detect change in piezo‐resistance due to applied pressure and to allow low‐voltage circuit operation. A simple 1‐bit first‐order delta‐sigma modulator is used to produce an output digital bitstream. The proposed interface circuit is realized in a 0.35 µm CMOS technology and draws less than 200 µA from a single 1.5 V power supply voltage. Simulation results show that the circuit can achieve an equivalent output resolution of 9.67 bits with less than 0.23% non‐linearity error.     

A Wired-AND Current-Mode Logic Circuit Technique in CMOS for Low-Voltage, High-Speed and Mixed-Signal VLSIC

A wired-AND current-mode logic (WCML) circuit techniquein CMOS technology for low-voltage and high-speed VLSI circuitsis proposed, and a WCML cell library is developed using standard0.8 micron CMOS process. The proposed WCML technique appliesthe analog circuit design methodologies to the digital circuitdesign. The input and output logic signals are represented bycurrent quantities. The supply current of the logic circuitis adjustable for the required logic speed and the switchingnoise level. The noise is reduced on the power supply lines andin the substrate by the current-steering technique and by thesmooth swing of the reduced node potentials. Precise analogcircuits and fast digital circuits can be integrated on the samesilicon substrate by using the low noise property of the WCML.It is shown by the simulations that at low supply voltages, theWCML is faster and generates less switching noise when comparedto the static-CMOS logic. At high speeds, the power dissipationof the WCML is less than that of the static-CMOS logic.     

基于概率转移矩阵的时序电路可靠度估计方法

传统的概率转移矩阵(Probabilistic Transfer Matrix,PTM)方法是一种能够比较精确地估计软差错对门级电路可靠度影响的方法,但现有的方法只适用于组合逻辑电路的可靠度估计.本文提出基于PTM的时序电路可靠度估计方法(reliability estimation of Sequential circuits based on PTM,S-PTM),先把待评估时序电路划分为输出逻辑模块和次态逻辑模块,然后用本文提出的时序电路PIM计算模型得到电路的PIM,最后根据输入信号的概率分布计算出时序电路的可靠度.用ISCAS 89基准电路为对象进行实验和验证,实验表明所提方法是准确和合理的.