基于65nm的SRAM低功耗电流型灵敏放大器的分析与设计

发布时间：2018-03-30 11:06

本文选题：灵敏放大器　切入点：低功耗　出处：《安徽大学》2015年硕士论文

【摘要】：灵敏放大器对SRAM (Static Random Access Memory)电路的性能提升起到无可替代的作用。它可以检测位线上的小摆幅信号并快速有效地进行放大,从而极大地提高SRA M的整体速度。因此,灵敏放大器广泛地被各类不同的SRAM电路使用。一般来说,灵敏放大器的结构可分为两大类：电压型和电流型灵敏放大器。电压型灵敏放大器依靠检测位线上的电压差值来进行放大输出,它结构简单,稳定性好,但受到位线负载电容的限制速度较慢;电流型灵敏放大器检测电流差值而进行放大,一般速度较快,但功耗高,稳定性差。灵敏放大器设计中需考虑多种指标,如速度,功耗,面积以及良率等,且几种因素彼此影响。在当今环境工艺不断进步、电源电压不断降低的情形下,速度和功耗会逐渐成为较为重要的两点因素。本文从上述两点要求出发,首先分析了灵敏放大器设计中的重点以及难点,提出研究的背景和意义。然后介绍了常用的几种灵敏放大器的结构和优缺点,最后通过对它们的总结和分析设计了一种低功耗电流型灵敏放大器。该放大器通过移除电路在非放电时间存在的的直流通路来较大幅度地降低功耗。电路的仿真在cadence中使用spectre仿真器进行,工艺设定为65nm,并使用多种工艺角分别仿真。仿真结果表明,在TT、SS、FF三种工艺角下,同传统的WTA型灵敏放大器相比,低功耗电流型灵敏放大器所费的功耗分别减小了64%、88%和68%；同时,放大器的放大速度相比于WTA型灵敏放大器也有一定的提升,通过对瞬态输出的分析得到,其放大速度在三种工艺角下分别增快了40%、38%和31%。另外,本文针对提出的灵敏放大器还给出了两种可用的改进方案电路：输入端补偿电路和抗闽值电压波动电路。主要设计于针对当前工艺条件下容易发生的不稳定因素及它们对电路可能造成的不良影响。其中,输入端补偿电路在原有的电路基础上增加了两个反相器和两个控制管,而抗阈值波动电路没有更多的器件添加。两种方案互有利弊,使用这两种方案可以有效的防止功能性失效的出现,提高放大器的准确度,但同时也增加了整体的功耗和面积。
[Abstract]:Sensitive amplifiers play an irreplaceable role in improving the performance of SRAM static Random Access memory circuits. They can detect small swing signals on bit lines and amplify them quickly and efficiently, thus greatly increasing the overall speed of SRA M. Sensitive amplifiers are widely used in various SRAM circuits. Generally speaking, The structure of sensitive amplifier can be divided into two categories: voltage mode and current type sensitive amplifier. Voltage mode sensitive amplifier amplifies the output by detecting voltage difference on the bit line. It has simple structure and good stability. However, the speed limited by the bit-line load capacitance is relatively slow, and the current mode sensitive amplifier amplifies by detecting the current difference, which is generally faster, but with high power consumption and poor stability. In the design of the sensitive amplifier, a variety of indexes should be considered, such as speed, power consumption, etc. Area, yield and so on, and several factors affect each other. With the continuous progress of environmental technology and the constant reduction of power supply voltage, speed and power consumption will gradually become more important two factors. This paper first analyzes the key points and difficulties in the design of sensitive amplifiers, puts forward the background and significance of the research, and then introduces the structure, advantages and disadvantages of several common sensitive amplifiers. Finally, a low power current-mode sensitive amplifier is designed by summing up and analyzing them. The amplifier can greatly reduce the power consumption by removing the DC path of the circuit in non-discharge time. Using the spectre emulator in cadence, The simulation results show that, compared with the conventional WTA sensitive amplifier, the power consumption of the low-power current-mode sensitive amplifier is reduced by 64% and 68%, respectively, in comparison with the conventional WTA type sensitive amplifier, and the simulation results show that the power consumption of the low-power current-mode sensitive amplifier is reduced by 64% and 68%, respectively. The amplification speed of the amplifier is also higher than that of the WTA sensitive amplifier. By analyzing the transient output, it is found that the amplification speed increases by 40% and 31% respectively at the three process angles. In this paper, two kinds of improved circuits for the sensitive amplifier are presented: the input compensation circuit and the anti-threshold voltage fluctuation circuit, which are mainly designed to deal with the unstable factors which are easy to occur under the current technological conditions. And their possible adverse effects on circuits. The input compensation circuit adds two inverters and two control tubes to the original circuit, but no more devices are added to the anti-threshold fluctuation circuit. The two schemes have advantages and disadvantages. Using these two schemes can effectively prevent the appearance of functional failure, improve the accuracy of amplifier, but also increase the overall power consumption and area.
【学位授予单位】：安徽大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN722

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