Reducing dynamic power consumption in synchronous sequential digital designs using retiming and supply voltage scaling

The problem of minimizing dynamic power consumption by scaling down the supply voltage of computational elements off critical paths is widely addressed in the literature for the case of combinational designs. The problem is NP-hard in general. To address the problem in the case of synchronous sequential digital designs, one needs to move some registers while applying voltage scaling. Moving these registers shifts some computational elements from critical paths, and can be done by basic retiming. Integrating basic retiming and supply voltage scaling to address this NP-hard problem cannot in general be done in polynomial run time. In this paper, we propose to first apply a guided retiming and then to apply supply voltage scaling on the retimed design. We devise new polynomial time algorithms to realize this guided retiming, and the supply voltage scaling on the retimed design. Also, we show that the problem in the case of combinational designs is not NP-hard for some combinational circuits with certain structure, and give a polynomial time algorithm to optimally solve it. Methods to determine lower bounds on the optimal reduction of dynamic power consumption are also provided. Experimental results on known benchmarks have shown that the proposed approach can reduce dynamic power consumption by factors as high as 61% for single-phase designs with minimal clock period. Also, they have shown that it can solve optimally the problem, and produce converter-free designs with reduced dynamic power consumption. For large size circuits from ISCAS'89 benchmark suite, the proposed algorithms run in 15 s-1 h.     

单片机控制下可变输出电压的电源设计

针对目前使用的开关电源几乎都采用旋钮开关调节电压,调节精度不高,而且经常跳变,使用麻烦的缺点,设计一种基于STC12C5A60S2单片机的可变输出电压的电源,使其功能更加完善并提高智能化程度。它产生两路47 k Hz的PWM脉冲信号,分别经过MOS驱动IC IR2104控制两个BUCK电路。单片机内部自带的10位ADC能通过电压电流检测电流实时反馈两路的电流和电压数值,并由此调整输出的PWM的占空比,形成电压闭环控制系统。设计按键能设置输出电压的大小、液晶屏显示实时输出电压与电流。测定显示在额定电流1 A输出的情况下,满载的供电效率为82%,输出电压误差小于0.15 V。     

简述变压变频电源期间核查的方法

期间核查也称为运行检查或中间核查.测量设备在两次校准或检定之间的时间间隔内,多次使用适当技术校核方法进行检查,以确保测量设备在"服役"期间一直维持良好状态的活动.变压变频电源作为实验室的重要仪器,其输出数据的准确性直接关乎到后续受试设备的各项工作指标,所以需要对变压变频电源进行期间核查以确保其有精确的输出.     

A modified MAP decoder architecture for low power consumption using folded technique

A modified MAP decoder architecture to reduce the power using folded technique is presented in this article. Firstly, the folded technique is applied in the interleaving and deinterleaving unit and then in the MAP decoder unit. The number of latches is reduced by using folded technique in the interleaving and deinterleaving unit. Here the end-to-end delay by using the proposed folded technique in the interleaving block is 2?M. But existing reports reveal that end-to-end delay is 2MN???2?M?+?2 for BI and M(N???1) for FCI. In addition to the end-to-end delay, the number of latches is also reduced by using folded technique. We have used only M???2 latches, whereas for other methods the number of latches utilised is more. The proposed MAP decoder reduce the memory elements up to 88% for the block interleaver, when M?=?NJ. In addition to that we achieved a memory element of 2 ^{K ?1?}+?4 when calculating LLR by applying folded technique in the MAP decoder. Total power consumption is 160.3mW when folded technique is used in the interleaving block and the MAP decoder section. This ratio is less than the existing reported values for K?=?5, code rate ½ and k?=?4.     

温度和电源电压监控器

在ＰＣ、服务器、工作站、办公设备、测试和测量仪器中需要监控温度和电源电压。Ｆａｉｒｃｈｉｌｄ公司的ＦＭＳ２７０１是一款温度和电压监控器件,通过ＳＭＢｌｌＳ串行接日可对它进行询问和控制。它的输出是模拟风扇控制电压、热报警和中断。ＦＭＳ２７０１框图示于图１。远程（ＤＩＯＤＥ十和ＤＩＯＤＥ－）和环境Ｍ极管温度传感器输入由多路转换器以ＩＨＺ速率逐一选取,然后激励Ａ／Ｄ变换器。数字化的二极管温度值存储在寄存器中。超出编程限制或断路点则将置位中断寄存器位和确定数字输出。通过引脚ＶＣＣＡＵＸ３和ＶＣＣ３监控电…     

Reducing power consumption in liquid-crystal displays

Power consumption in liquid-crystal displays is analyzed by including frequent polarity reversals and duty-cycle control. A multistep voltage profile is proposed to reduce the power consumption of multiplexed and nonmultiplexed displays. The authors have also shown that the reduction in the power consumption can be achieved with a minimal increase in hardware complexity of the drive electronics.     

A technique for power supply harmonic impedance estimation using acontrolled voltage disturbance

A method for power system impedance estimation is presented. The method employs a power converter to inject a voltage transient onto the supply system. As the technique employs controlled power electronic devices it may be used as a stand alone piece of a portable measurement equipment, or it may be embedded into the functions of an active shunt filter for improved harmonic control. The impedance is estimated through correlation of the measured voltage and current transients. Simulations and experimental results demonstrate the measurement technique is highly accurate and effective     

1.5 V power supply CMOS voltage squarer

A CMOS voltage squarer for low voltage applications is proposed. The circuit works with a 1.5 V power supply and provides a THD of <3% with input signals up to 260 mV_pp. A 0.3% lower THD is achieved with input signals up to 120 mV_pp     

A linear temperature probe with a low power supply voltage

A new principle of arranging temperature measurements in integrated temperature probes is suggested that makes it possible to attain a high linearity in a simple way. Circuitry implementation and techniques that allow one to reduce power supply voltage are considered. The experimental results obtained are given.     

Design of a Viterbi decoder with low power using minimum-transitiontraceback scheme

The authors propose a novel traceback scheme for the implementation of a low power Viterbi decoder. With minor modification of a conventional traceback scheme, the memory access count needed to perform the traceback function can be reduced by a factor of ~5.0-10.0 over the conventional traceback scheme. Experimental results confirm the efficiency of the proposed scheme     

高电源电压抑制比基准电压源的设计

在此通过对带隙基准电压源电路进行建模分析,针对逆变电路的中低频使用环境,设计了一个应用于高压逆变器电路中的高电源电压抑制比,低温度系数的带隙基准电压源。该电路采用1μm,700 V高压CMOS工艺,在5 V供电电压的基础上,采用一阶温度补偿,并通过设计高开环增益共源共栅两级放大器来提高电源电压抑制比,同时使用宽幅镜像电流偏置解决因共源共栅引起的输出摆幅变小的问题。基准电压源正常输出电压为2.394 V,温度系数为8 ppm/℃,中低频电压抑制比均可达到-112 dB。     

Reducing the power consumption of two-dimensional logic transistors

The growing demand for high-performance logic transistors has driven the exponential rise in chip integration,while the transistors have been rapidly scaling down to sub-10 nm.The increasing leakage current and subthreshold slope(SS) induced by short channel effect(SCE) result in extra heat dissipation during device operation.The performance of electronic devices based on two-dimensional(2D) semiconductors such as the transition metal dichalcogenides(TMDC) can significantly reduce power consumption,benefiting from atomically thin thickness.Here,we discuss the progress of dielectric integration of 2D metal–oxide–semiconductor field effect transistors(MOSFETs) and 2D negative capacitance field effect transistors(NCFETs),outlining their potential in low-power applications as a technological option beyond scaled logic switches.Above all,we show our perspective at 2D low-power logic transistors,including the ultra-thin equivalent oxide thickness(EOT),reducing density of interface trap,reliability,operation speed etc.of 2D MOSFETs and NCFETs.     

从电压较高的电源获取较低直流电压的电路

如果使用图1中的电路,那么您不用求助于电噪声很大的DC/DC转换器,也不必在降压电阻器中浪费功率,就能从电压较高并经整流的正弦电压源获得5VDC等很低的稳定电压。该应用需要一个稳定的5VDC源,但是变压器向全波桥式整流器供应18Vrms。在充电阶段,两个等值电解电容器C1和C2在通过     

Reducing voltage rating and cost of vehicle power systems with a new transient voltage suppression technology

Power electronics plays a critical role in modern vehicle systems. The voltage rating of vehicle power electronics is predominantly determined by the transient immunity requirement, which considerably exceeds the maximum operating voltages of the 14 V and 28 V vehicle power systems, and imposes a large cost penalty. In contrast, the emerging 42 V systems require a much improved bus voltage regulation to maintain system affordability. We discuss the feasibility of reducing the DC breakdown voltage requirement and subsequently the cost of various vehicle power systems by employing a new class of semiconductor transient voltage suppressors, termed MOSTVS. The MOSTVS, combining power MOSFET and polysilicon thin-film technologies, provides a much more accurately controlled clamping voltage than conventional Zener diodes and MOVs over a wide range of current and temperature. The MOSTVS can be used in the conventional alternator/rectifier/regulator configuration or the more advanced drivetrain motor/generator configuration. It is estimated that the cost of power semiconductor transistors and filter capacitors can be reduced by up to 70% if the voltage rating of the 14 V automotive system is reduced from 50 to 30 V. Similar benefits can also be achieved in the 28 V and 42 V systems.     

脉宽连续可调并带前峰的大功率激光方波电源

本文给出了一种用快速大功率可控硅构成的带前峰的激光方波电源,方波宽度从0.5ms到连续,方波幅度从几十A到几百A分别连续可调。用可控硅做斩波器,比用功率晶体管做的斩波器具有电流大、耐压高、过载能力强等特点,文中对开关过程进行了分析,并提出了设计公式。     

A voltage fed transistorized induction heating power supply

A prototype voltage fed MOSFET power supply for high frequency induction heating applications is described. Special emphasis is given to the practicalities of paralleling MOSFETs under these conditions, the protection circuitry required, and the use of PWM as a means of power control.     

可提供任意极性电压和电流的四象限电源

常规的电源只能工作于第一象限,为负载提供正的输出电压和电流;或者,通过故意将输出误接,作为"负"电源静态地工作于第三象限.但是,常规的电源既不能工作在第二象限(例如,作为负电源的可调负载),也不能工作于第四象限(例如用特定恒流进行电池放电测试).此外,它还不能作为负载条件或控制输入的函数,在各种工作模式之间进行天衣无缝的转换.图1所示电路采用了"互补的"传输晶体管配置,具有类似普通音频功率放大器的输出拓扑结构,可以实现全四象限功能.这一互补部分在较低电流设计中可以是基本的运算放大器输出端,而在涉及较大功率的情况下,可以使用外接功率MOSFET.当采用LT1970功率运算放大器来控制电路的工作时,由于它具有内部闭环限流特性,控制各种工作模式下的输出就变得非常简单.     

一种抗辐射前置稳压高压电源

以一种高压电源的前置稳压电路作为研究对象,重点分析稳压控制电路的抗中子抗辐射能力。对导致中子辐照前后输出电压变化量的因素进行分析,并对关键元器件晶体管进行辐照效应分析和试验验证,提出了晶体管优化和采用达林顿晶体管结构2种加固措施。通过电路仿真和制作样机,得到在1 MeV等效中子2×1013 n/cm2中子注量后的仿真和实测结果与理论分析值相吻合,验证了抗辐射加固措施的有效性。     

Reliable study of digital IC circuits with margin voltage among variable DC power supply, electromagnetic interference and conducting wire antenna

This paper measures the margin voltage of a digital IC circuit in order to assess the deterioration of the margin voltage caused by variations in the DC power supply, electromagnetic interference (EMI), and the corresponding power induced in a conducting wire antenna (CWA). The present results confirm that these factors may influence the margin voltage to such an extent that the operation of the digital IC circuit may fail. This paper provides a theoretical analysis of the influence of these factors upon the margin voltage, and develops corresponding equations, which are then applied with appropriate parameter values to determine an optimal circuit operation. It is shown that the deteriorated margin voltage of the IC circuit is a function of the amplitude and frequency of the EMI source, and of the parasitic capacitance of the device, i.e. the greater the EMI amplitude and frequency, and the higher the capacitance of the device, the greater the likelihood that its operation will fail when subjected to a variable DC supply voltage, or to EMI and CWA effects. Furthermore, in the case of EMI, it is shown that an increased interference frequency will reduce the margin voltage of the device. Finally, it is noted that the smaller the input impedance of the IC device, the greater the influence of EMI is likely to be.     

低压电网中的接地类型与供电系统

文章针对这几种接地形式和系统的各自所具备的特性优势和劣势及其在实际运用当中的具体应用的方向做出了简要的探讨.