基于cmos反相器的可精确计算延时电路

cmos反相器振荡电路功率计算CMOS反相器振荡电路功率计算引言：CMOS反相器振荡电路是一种常用的时钟信号产生电路，广泛应用于数字系统和通信领域。

在设计和分析CMOS反相器振荡电路时，了解其功率特性是非常重要的。

本文将介绍CMOS反相器振荡电路的功率计算方法，并探讨一些影响功率的关键因素。

一、CMOS反相器振荡电路简介CMOS反相器振荡电路由两个互补的MOSFET（金属-氧化物-半导体场效应晶体管）构成，其中一个是NMOS（n型MOSFET），另一个是PMOS（p型MOSFET）。

这两个MOSFET的栅极相连，形成一个反相器。

当输入信号通过反相器时，输出信号与输入信号相位相反。

二、CMOS反相器振荡电路功率计算方法1. 静态功耗计算静态功耗是指当CMOS反相器振荡电路处于稳态时的功耗。

由于CMOS反相器振荡电路的输出始终处于高电平或低电平，所以在稳态下，输入信号的功耗非常小，可以忽略不计。

因此，静态功耗主要来自于漏电流。

漏电流的大小与MOSFET的阈值电压、温度和电源电压有关。

可以通过查阅MOSFET的规格书来获得漏电流的数值。

2. 动态功耗计算动态功耗是指当CMOS反相器振荡电路在切换过程中的功耗。

由于CMOS反相器振荡电路是通过周期性的输入信号切换来产生时钟信号的，所以在切换过程中会有一定的功耗。

动态功耗主要来自于充电和放电过程中的能量损耗。

具体的计算方法如下：- 充电功耗计算：当输入信号从高电平切换到低电平时，NMOS导通，PMOS截止，CMOS反相器的输出电压从低电平切换到高电平。

在这个过程中，NMOS的开通导致电荷从电源电压充入电容，产生能量损耗。

充电功耗可以通过如下公式计算：Pcharge = 1/2 * C * Vdd^2 * f其中，C是CMOS反相器的等效电容，Vdd是电源电压，f是输入信号的频率。

- 放电功耗计算：当输入信号从低电平切换到高电平时，NMOS截止，PMOS导通，CMOS反相器的输出电压从高电平切换到低电平。

宽长比对CMOS反相器延迟时间影响的分析张照锋; 董海青【期刊名称】《《电子测试》》【年(卷),期】2019(000)017【总页数】2页(P46-47)【关键词】宽长比; 反相器; 延迟时间【作者】张照锋; 董海青【作者单位】南京信息职业技术学院江苏南京 210023【正文语种】中文0 引言延迟时间是信号在集成电路单元内部传输所要花费的时间。

一般情况下延迟时间包括两个：高电平到低电平的传输延迟时间tPHL、高电平到低电平的传输延迟时间tPLH。

1 CMOS反相器CMOS反相器包括一个PMOS晶体管和一个NMOS晶体管，其电路图如图1所示。

图1 CMOS反相器结构本次设计的CMOS反相器所用库文件为EDA工具自带元器件库，工艺特征尺寸为0.25μm。

后续仿真过程中，将会改变两个MOS晶体管的沟道宽度，进而计算对应沟道长度下的传输延迟时间。

2 仿真设定通过EDA工具生成CMOS反相器的Spice网表文件。

然后为该网标文件添加元器件模型库、工作电源、输入信号、仿真设定和输出设定等信息，完成的反相器仿真网表文件内容如下所示。

*INV Simulation反相器仿真网表MM1n F1 A Gnd 0 NMOS25 W=1.5u L=250n M=1MM2p F1 A Vdd Vdd PMOS25 W=1.5u L=250n M=2.lib“D：\exp1\Generic_250nm.lib”ttVVdd Vdd Gnd 2.5VVa A Gnd PULSE (0 2.5 5n 5n 5n 50n 100n).tran 1n 400n.print tran v(A) v(F1).end为了计算两个信号传输延迟时间，需要在网表文件中添加相应的测量命令，测量命令的源代码如下所示。

.measure tran tPHL trig V(A) val=1.25 rise=2 targ V(F1)val=1.25 fall=2.measure tran tPLH trig V(A) val=1.25 fall=2 targ V(F1)val=1.25 rise=2仿真测量的结果如下所示，分别列出了计算的最后结果。

基于逻辑功效模型的CMOS数字集成电路延迟的估算与优化一、摘要CMOS数字集成电路中，快速的延迟估算对于关键路径的设计是非常必要的。

模拟或者时序分析只能告诉我们某个特定电路的速度有多快，但不能解决如何改进电路使其速度更快这类问题。

本文将建立逻辑功效模型，快速估算出延迟时间，发现来源，找出缩短延迟方法。

本文将重点介绍如何选择逻辑的级数，逻辑门类型和MOS管尺寸来对逻辑和电路优化。

关键词：CMOS数字集成电路；逻辑功效模型；延迟二、寄生延迟与逻辑功效t等于从输入信号跨越50%到输出信号跨越50%所需的最大时间。

门的传输延迟时间pd我们认为门的传输延迟由两部分构成，一部分是门没有负载时的寄生延迟，一部分是由门本身的驱动能力和它的负载共同来决定的功效延迟。

门的寄生延迟是当这个门驱动零负载时的延迟。

手工计算时一种粗略的办法就是只计算输出节点上的扩散电容。

我们可以使用RC延迟模型来计算这个延迟的大小。

我们选择每个门中MOS管的宽度使其对应的电阻大小为R，这里我们认为单位NMOS管具有有效电阻R。

单位PMOS管电阻2R，单位晶体管的栅电容定义为C，源漏区寄生电容也等于C (约2fF/um 栅宽) 。

如图1，为了做到无偏斜，我们把PMOS管的宽度做到2倍NMOS管，单位反向器在输出端上有3个单位的扩散电容，输出端电平变化时，要通过电阻R对三个单位的扩散电容进行充或者放电，因此其寄生延迟为3RC=τ。

我们把无偏斜单位反相器的寄生延迟定义为标准寄生延迟，为简便起见我们把它看成是1。

与非门在输出端都有6个单位的扩散电容，因此其寄生延迟就是两倍大小，简记为2。

图1表1估算出了一些常见门的寄生延迟。

增大晶体管的尺寸能够减少电阻但却相应增加了电容，因此在一阶精度上寄生延迟与们的尺寸大小无关。

表1 一些常见门的寄生延迟的电容，如图1，一个2输入与非门的模型，如上方的输入型号等于1，而最底部的输入信号开始从0到1上升，这个与非门也必须对内部节点的扩散电容进行放电。

CMOS反相器由本书模拟部分已知，MOSFET有P沟道和N沟道两种，每种中又有耗尽型和增强型两类。

由N沟道和P沟道两种MOSFET组成的电路称为互补MOS或CMOS电路。

下图表示CMOS反相器电路，由两只增强型MOSFET组成，其中一个为N沟道结构，另一个为P沟道结构。

为了电路能正常工作，要求电源电压V DD大于两个管子的开启电压的绝对值之和，即V DD＞(V TN＋|V TP|) 。

1.工作原理首先考虑两种极限情况：当v I处于逻辑0时，相应的电压近似为0V；而当v I处于逻辑1时，相应的电压近似为V DD。

假设在两种情况下N沟道管T N为工作管P沟道管T P为负载管。

但是，由于电路是互补对称的，这种假设可以是任意的，相反的情况亦将导致相同的结果。

下图分析了当v I=V DD时的工作情况。

在TN的输出特性i D—v DS（v GSN ＝V DD）(注意v DSN=v O)上，叠加一条负载线，它是负载管T P在v SGP=0V 时的输出特性i D－v SD。

由于v SGP＜V T（V TN=|V TP|=V T），负载曲线几乎是一条与横轴重合的水平线。

两条曲线的交点即工作点。

显然，这时的输出电压v OL≈0V（典型值＜10mV ，而通过两管的电流接近于零。

这就是说，电路的功耗很小（微瓦量级）下图分析了另一种极限情况，此时对应于v I＝0V。

此时工作管T N在v GSN ＝0的情况下运用，其输出特性i D－v DS几乎与横轴重合，负载曲线是负载管T P在v sGP＝V DD时的输出特性i D－v DS。

由图可知，工作点决定了V O＝V OH≈V DD；通过两器件的电流接近零值。

可见上述两种极限情况下的功耗都很低。

由此可知，基本CMOS反相器近似于一理想的逻辑单元，其输出电压接近于零或+V DD，而功耗几乎为零。

2.传输特性下图为CMOS反相器的传输特性图。

图中V DD=10V，V TN=|V TP|=V T= 2V。

Contents•Defining “Delay” in a circuito Propagation delayo Transition timeo Practical input signals•“Rise-time” and “Fall-time”o Approximate Calculationo Inference from approximate calculationo Accurate calculations•Factors affecting propagation delay in CMOS inverterso Threshold Voltageo Width (W) of the MOSFETSo Supply voltageo Capacitive loado Short channel effectso Maximum operating frequency•The capacitance of CMOS inverters•ConclusionDefining “Delay” in a circuitEvery circuit has some parasitic capacitance components associated with it.In the chapter for non-ideal effects in MOSFETs, we have discussedthe parasitic capacitance present in the MOSFET device. These capacitance results in delaying the voltage change in the circuit. So we will getlimitations in our speed of operation depending on how fast we can charge or discharge these capacitors.To illustrate how the capacitances affect the output waveforms, we take some examples of waveforms. 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9.1 图题9.1是用两个555定时器接成的延时报警器。

当开关S 断开后，经过一定的延迟时间后，扬声器开始发声。

如果在延迟时间内开关S 重新闭合，扬声器不会发出声音。

在图中给定参数下，试求延迟时间的具体数值和扬声器发出声音的频率。

图中G 1是CMOS 反相器，输出的高、低电平分别为V OH =12V ，V OL ≈0V 。

图题9.5解：1.工作原理：图题9.1由两级555电路构成，第一级是施密特触发器，第二级是多谐振荡器。

施密特触发器的输入由R 1、C 1充放电回路和开关S 控制，当S 闭合时，V C =0V ，施密特触发器输出高电平。

施密特触发器的输出经反相器去控制多谐振荡器的R D 端，当施密特触发器的输出为高电平时，R D =0，多谐振荡器复位，扬声器不会发出声音。

当开关S 断开后，R 1、C 1充放电回路开始充电，V C 随之上升，但在达到CC T 32V V =+之前，施密特触发器的输出仍为高电平时，R D =0，扬声器仍不会发出声音。

这一段时间即为延迟时间。

一旦V C 达到CC T 32V V =+，施密特触发器触发翻转，输出低电平，R D =1，多谐振荡器工作，扬声器开始发声报警。

2.求延迟时间：延迟时间由R 1、C 1充放电回路的充电过程决定：τtev v v v -+∞-+∞=)]()0([)(C C C C将 V 12)(CC C ==∞V v )0(C +v =0V τ=R 1C 1代入上式，得： )1(11CC C C R t eV v --=t=t 1时，CC C 32V v =代入上式，整理得延迟时间：t 1= R 1C 1ln3≈1.1 R 1C 1=1.1×106+10×10-6=11S扬声器发声频率：MHz 95.01001.010157.01)2(7.0163232≈⨯⨯⨯⨯=+=-C R R f9.2图题9.2所示电路是由两个555定时器构成的频率可调而脉宽不变的方波发生器，试说明其工作原理；确定频率变化的范围和输出脉宽；解释二极管D 在电路中的作用。

数字集成电路设计
实验报告
一、实验目的
通过实验了解CMOS反相器的工作原理，能自己用CMOS和PMOS 连接电路。

通过设置不同的measure参数表，求得上升延迟、下降延迟、高电平转低电平的延迟时间、低电平转高电平的延迟时间。

二、实验内容
1、用软件求出输入输出电压曲线
2、通过设置不同的参数求得上升延迟tr、下降延迟tf、高电平转低电平的延迟时间thl、低电平转高电平的延迟时间tlh。

三、实验原理
四、实验步骤
VTC曲线
最终求得上升延迟tr 、下降延迟tf 、高电平转低电平的延迟时间thl 、低电平转高电平的延迟时间tlh 。

五、实验心得
本次实验虽与上次实验相似，只是所求不一样。

通过改变参数，求得上升延迟tr、下降延迟tf、高电平转低电平的延迟时间thl、低电平转高电平的延迟时间tlh，使我进一步了解mos管延迟。

集成电路设计基础_华中科技大学中国大学mooc课后章节答案期末考试题库2023年1.画小信号等效电路时，恒定电流源视为。

答案:开路2.模拟集成电路设计中可使用小信号分析方法的是。

答案:增益3.模拟集成电路设计中可使用大信号分析方法的是（）。

答案:输出摆幅4.题1-1-1 中国高端芯片联盟正式成立时间是：。

答案:2016年7月5.题1-1-2 如下不是集成电路产业特性的是：。

答案:低风险6.题1-1-3 摩尔定律是指集成电路上可容纳的晶体管数目，约每隔：个月便会增加一倍，性能也将提升一倍。

答案:187.MOS管的小信号模型中，体现沟长调制效应的参数是（）。

答案:8.工作在饱和区的MOS管，可以被看作是一个。

答案:电压控制电流源9.下图中的MOS管工作在区（假定Vth=0.7V）。

【图片】答案:饱和区10.一个MOS管的本征增益表述错误的是。

答案:与MOS管电流无关11.工作在区的MOS管，其跨导是恒定值。

答案:饱和12.MOS管中相对最大的寄生电容是。

答案:栅极氧化层电容13.MOS管的小信号输出电阻【图片】是由MOS管的效应产生的。

答案:沟长调制14.题1-1-4 摩尔定律之后，集成电路发展有三条主线，以下不是集成电路发展主线的是：。

答案:SoC15.题1-1-5 单个芯片上集成约50万个器件，按照规模划分，该芯片为：。

答案:VLSI16.题1-1-6 年发明了世界上第一个点接触型晶体管。

答案:194717.题1-1-7 年发明了世界上第一块集成电路。

答案:195818.题1-1-8 FinFET等多种新结构器件的发明人是：。

答案:胡正明19.题1-1-9 集成电路代工产业的缔造者：。

答案:张忠谋20.题1-1-10 世界第一块集成电路发明者：。

答案:基尔比21.MOS管一旦出现现象，此时的MOS管将进入饱和区。

答案:夹断22.MOS管从不导通到导通过程中，最先出现的是。

答案:耗尽23.在CMOS模拟集成电路设计中，我们一般让MOS管工作在区。

数字集成电路学习总结5CMOS反相器今天开始总结数字集成电路。

这本书其实算是本科最难的⼀本了，细节过多⽆法卒读，涉及到的知识也⾮常全⾯。

实际上本科课程安排中并为将其作为重点，我们的课⾮常⽔，不知道讲了什么。

今天详细总结⼀下。

当时然由于内容过多，⽆法全部涵盖，只能⼤致总结，并着重记录定性的结论。

涉及到计算之类的问题，就只能略过了。

第五章 COMS反相器5.1 引⾔为什么从第五章开始，原因是这章⽐较基础，详细学习CMOS反相器后，才能继续看组合电路和时序电路等等。

研究的对象有如下⼏个指标：成本（复杂性和⾯积）、完整性和稳定性（静态特性）、性能（动态特性）、能量效率（功耗）。

5.2 静态CMOS反相器——直观综述课本上的描述：晶体管只不过是⼀个具有⽆限关断电阻和有限导通电阻的开关。

以开关来理解，可以推导出其他重要特性：1、输出⾼电平和低电平分别为VDD和GND，换⾔之，电压摆幅等于电源电压。

因此噪声容限很⼤。

2、逻辑电平与器件的相对尺⼨⽆关，所以晶体管可以采⽤最⼩尺⼨。

这⾥有⼀个概念叫⽆⽐逻辑3、稳态时，输出和VDD或GND之间总存在有限电阻的通路。

因此⼀个设计良好的CMOS反相器具有低输出阻抗，这使得它对噪声和⼲扰不敏感。

4、输⼊电阻极⾼。

理论上，单个反相器可以驱动⽆穷个门，或者说有⽆穷⼤的扇出。

但很快我们发现增加扇出也会增加传播延时。

因此扇出不会影响稳态特性，会影响瞬态特性。

5、忽略漏电流的话，意味着⽆静态功耗。

之前常⽤的是NMOS电路，静态功耗不为0，限制了集成度。

后来必须转向CMOS。

电压传输特性（VTC）的性质和形状可以通过图解法迭加两管的图像得到。

结果是观察到VTC具有⾮常窄的过渡区。

我们可以把开关特性简化为RC电路，⼀个快速门的设计是通过减⼩输出电容或者减⼩晶体管的导通电阻（增⼤宽长⽐）实现的。

5.3 CMOS反相器稳定性的评估——静态特性5.3.1 开关阈值开关阈值VM定义是Vin=Vout的点，利⽤图解法可以看出。