低功耗三值双边沿触发器设计

提出了几种分别采用两个锁存器和单个锁存器的三值双边沿触发器设计方案，这些方案包括动态、半静态和静态结构。双锁存器三值双边沿触发器是通过将两个透明的三值闩锁并列构成的。单个锁存器的三值双边沿触发器设计是通过时钟信号的上升沿及下降沿后分别产生的窄脉冲使锁存器瞬时导通完成取样求值。三值双边沿触发器具有对时钟信号的两个跳变均敏感的特点，因此可以抑制时钟信号的冗余跳变。较之三值单边沿触发器，在保持相同数据吞吐量的条件下，采用三值双边沿触发器可使时钟信号的频率减半，从而降低系统功耗。最后给出了采用0．25μm CMOS工艺参数的HSPICE模拟结果及其功耗比较。     

电流型CMOS脉冲D触发器设计

该文根据脉冲触发器的设计要求,结合阈算术代数系统,提出一种电流型CMOS脉冲D触发器的通用结构,用于二值及多值电流型CMOS脉冲触发器的设计,并可方便地应用于单边沿和双边沿触发。在此结构的基础上设计了电流型CMOS二值、三值以及四值脉冲D触发器。采用TSMC 180 nm CMOS工艺参数对所设计的电路进行HSPICE模拟后表明所设计的电路具有正确的逻辑功能和良好的瞬态特性,且较以往文献提出的电流型D触发器,优化了触发器的建立时间和保持时间,二值和四值触发器最差最小D-Q延时比相关文献的主从触发器降低了59.67%和54.99%,比相关文献的边沿触发器降低了4.62%以上,所用晶体管数也相对减少,具有更简单的结构以及更高的电路性能。     

一种单锁存器CMOS三值D型边沿触发器设计

提出了一种只使用单个锁存器的CMOS三值D型边沿触发器设计.该电路是通过时钟信号的上升沿后产生的窄脉冲使锁存器瞬时导通完成取样求值.所提出的电路较之以往设计具有更为简单的结构,三值双轨输出时仅需24个MOS管.计算机模拟结果验证了所提出的触发器具有正确的逻辑功能、良好的瞬态特性和更低的功耗.此外,该设计结构极易推广至基值更高的多值边沿触发器的设计.     

一种单锁存器CMOS静态D触发器的设计

提出了一种只使用单锁存器的ＣＭＯＳ静态Ｄ触发器结构．由于它比普通的主从型Ｄ触发器少一个锁存器,故所需的管子数少,从而节省了面积．该单锁存器型Ｄ触发器还具有对时钟上升时间不敏感的优点     

反馈式ECL记忆门的记忆性能和移位计数器

经过数学论证表明,改进反馈式ECL(MFECL)门可在二个状态中任一态保持稳定,所以认为MFECL门就是一种ECL记忆门或D锁存器.提出了一种由两个ECL记忆门组成的ECL主从D触发器.在上述理论基础上,利用此主从D触发器设计出5进制移位型计数器.经过计算机模拟上述电路,验证了理论和电路的正确性.     

反馈式ECL记忆门的记忆性能和移位计数器

经过数学论证表明,改进反馈式ECL(MFECL)门可在二个状态中任一态保持稳定,所以认为MFECL门就是一种ECL记忆门或D锁存器.提出了一种由两个ECL记忆门组成的ECL主从D触发器.在上述理论基础上,利用此主从D触发器设计出5进制移位型计数器.经过计算机模拟上述电路,验证了理论和电路的正确性.     

时钟低摆幅双边沿低功耗触发器的设计

传统的时钟低摆幅触发器由于工作方式和电路结构不够合理,使得电路的结点电容和开关活动性较大,增加了电路的开关功耗.本文通过改进传统的时钟低摆幅触发器的工作方式和电路结构,设计了一种新型的时钟低摆幅双边沿触发器--反馈保持型时钟低摆幅双边沿触发器(Feedback Keeper Low-swing Clock Double-edge-triggered Flip-flop-FK-LSCDFF).模拟结果表明所设计的触发器具有正确的逻辑功能,跟传统的时钟低摆幅双边沿触发器相比,降低近17%的功耗.     

交叉耦合绝热动态触发器及同步动态时序电路

本文提出交叉耦合绝热动态触发器及其同步时序电路综合方法。首先利用文献[1]的电路三要素理论定量描述交叉耦合型绝热锁存器，由绝热主锁存器和从锁存器构成一个单相输入的绝热触发器。在交叉耦合型绝热触发器的基础上，本文提出绝热同步动态时序电路综合方法，用此法设计出绝热8421BCD码错码检测电路（仅用50管），总功耗小于三个绝热ADL非门的功耗，计算机模拟验证本文方法的正确性。     

改进DICE结构的D触发器抗SEU设计

基于DICE结构主-从型D触发器的抗辐照加固方法的研究,在原有双立互锁存储单元(DICE)结构D触发器的基础上改进电路结构,其主锁存器采用抗静态、动态单粒子翻转(SEU)设计,从锁存器保留原有的DICE结构。主锁存器根据电阻加固与RC滤波的原理,将晶体管作电阻使用,使得电路中存在RC滤波,通过设置晶体管合理的宽长比,使其与晶体管间隔的节点的电平在SEU期间不变化,保持原电平状态,从而使电路具有抗动态SEU的能力。Spectre仿真结果表明,改进的D触发器既具有抗动态SEU能力,又保留了DICE抗静态SEU较好的优点,其抗单粒子翻转效果较好。     

新型CMOS JK触发器

该文以双反相器闩锁电路为基本存贮单元,采用开关级设计方法设计出一种新型的CMOS JK触发器。与传统设计相比,新设计具有较简单的结构、较少的元件以及较快的工作速度。     

Conditional-capture flip-flop for statistical power reduction

This paper describes a family of novel low-power flip-flops, collectively called conditional-capture flip-flops (CCFFs). They achieve statistical power reduction by eliminating redundant transitions of internal nodes. These flip-flops also have negative setup time and thus provide small data-to-output latency and attribute of soft-clock edge for overcoming clock skew-related cycle time loss. The simulation comparison indicates that the proposed differential flip-flop achieves power savings of up to 61% with no impact on latency while the single-ended structure provides the maximum power savings of around 67%, as compared to conventional flip-flops. With a typical switching activity of 0.33, the power consumption is reduced by as much as 23-30% with comparable minimum data-to-output latency. It is also indicated that the proposed single-ended structure provides power comparable to the fully static master-slave design with significantly reduced data-to-output latency. An eight-bit counter was fabricated using a 0.35-μm CMOS technology, and the experimental results indicate that the counter using the differential CCFF saves the overall power consumption by about 30% as compared to that using the conventional flip-flop     

CMOS触发器的一种传输函数分析法

触发器是构成时序逻辑电路的存储单元和核心部件。利用开关级设计的CMOS传输函数理论和信号流图,讨论了CMOS主从D触发器的工作原理;提出了CMOS触发器的一种传输函数分析法,并给出了应用实例。可以看出,这种方法对于CMOS触发器电路分析和设计是有效且方便的。     

Metastability tests of flip-flops in programmable digital circuits

This paper describes the methods and experimental techniques for determination of the metastability behavior of the flip-flops used in the programmable digital circuits. A dual model of the metastability distinguishes two transitions at the flip-flop output (L/H and H/L) which have different impact on the Mean Time Between Failures (MTBF) of the flip-flop. A new circuit of the late transition detector (LTD) allows for determination of the pairs of the metastability parameters, the window W and the time constant τ, for both transitions. The test results are presented for four types of programmable digital circuits fabricated commercially in CMOS technology. In the all tests, the H/L transition clearly dominates with respect to MTBF (as a worse one). The presented test methods can also be used for evaluation of flip-flops in nonprogrammable digital circuits.     

Low power double edge-triggered flip-flop using one latch

A low power double edge-triggered (DET) flip-flop using a single latch is presented. In the proposed circuit data are sampled into the latch during a short transparency period for each edge of the clock signal. The proposed flip-flop requires small silicon area and has lower power dissipation with respect to previously reported DET flip-flops     

Prescaler using complementary clocking dynamic flip-flop

A prescaler using complementary clocking dynamic flip-flops (CCD-FF) is presented and implemented in a synthesiser using 0.18 /spl mu/m CMOS technology. The maximum operating frequency of the proposed CCD-FF is up to about 10 GHz and the prescaler using this flip-flop operates up to 5.1 GHz. The proposed CCD-FF has not only a high operating frequency but also low power consumption since it is based on the scheme of the conventional true single phase clocking (TSPC) flip-flop with no static DC current. The RMS current consumption of designed 16/17 dual-modulus prescaler is only 1.39 mA at 4 GHz.     

Low power flip-flop with clock gating on master and slave latches

A new flip-flop is presented in which power dissipation is reduced by deactivating the clock signal on both the master and slave latches when there are no data transitions. The new circuit overcomes the clock duty-cycle constraints of previously proposed gated flip-flops. The power consumption of the presented circuit is significantly lower than that of a conventional flip-flop when the D input has a reduced switching activity     

High-performance and low-power conditional discharge flip-flop

In this paper, high-performance flip-flops are analyzed and classified into two categories: the conditional precharge and the conditional capture technologies. This classification is based on how to prevent or reduce the redundant internal switching activities. A new flip-flop is introduced: the conditional discharge flip-flop (CDFF). It is based on a new technology, known as the conditional discharge technology. This CDFF not only reduces the internal switching activities, but also generates less glitches at the output, while maintaining the negative setup time and small D-to-Q delay characteristics. With a data-switching activity of 37.5%, the proposed flip-flop can save up to 39% of the energy with the same speed as that for the fastest pulsed flip-flops.     

Analysis of mesastable operation in RS CMOS flip-flops

An analysis of metastable operation in CMOS RS flip-flops is presented. An analytical formula for the flip-flop resolving time constant was derived using Shichman-Hodges model for NMOS and PMOS transistors. This formula, as related to the transistor dimensions, fabrication process parameters, and parasitic capacitance, uses proper transistor sizing to attain minimum flip-flop failure rate due to metastable operation. CMOS n-well, p-well, and twin-well flip-flop performance predicted analytically is also approved by SPICE level one simulation of transistor models. Real-time oscilloscope displays of metastable operation for two different CMOS RS flip-flop circuits are demonstrated.     

Aging comparative analysis of high-performance FinFET and CMOS flip-flops

This paper presents a comparative performance analysis to investigate the impact of aging mechanisms on various flip-flops in CMOS and FinFET technologies. We consider Bias Temperature Instability (BTI) and Hot Carrier Injection (HCI) effects on the robustness of high performance flip-flops. To apply BTI and HCI aging mechanisms, we utilize long-term model to estimate ∆ V_th and employ the updated V_th in transistor model file. The simulation results on performance analysis indicate the high ranking of various flip-flops considering speed and power consumption in each CMOS and FinFET technologies, moreover, approve the superiority of static FinFET flip-flops over CMOS flip-flops. In addition, a comparative analysis considering temperature and V_DD variations over different FinFET flip-flop structures demonstrates the average percentages of T_DQmin and PDP degradation against aging mechanisms are significantly less than similar CMOS flip-flops.