1、 原文： Digital circuit definition: Completes with the digital signal to the digital quantity carries onthe arithmetic operation and the logic operation electric circuit iscalled the digital circuit, or number system. Because it has the logicoperation and the logical processing function, therefore call
2、s thenumeral logic circuit. Numeral logic circuit classification (according to function minute): 1st, combinatory logic electric circuit The abbreviation combination circuit, it becomes by the mostbasic logical gate electric circuit combination. The characteristicis: Output value only and then input
3、 value related, namely output onlyby then input value decision. The electric circuit has not rememberedthe function, the output condition changes along with the inputcondition change, is similar to the resistance electric circuit, likethe accumulator, the decoder, the encoder, the data selector and
4、so onall belong to this kind. 2nd, succession logic circuit The abbreviation sequence circuit, it is adds on the feedbacklogic return route by the most basic logical gate electric circuit (tooutput the electric circuit which input) or the component combinationbecomes, lies in the sequence circuit wi
5、th the combination circuitessence difference to have the memory function. The sequence circuitcharacteristic is: The output not only was decided by then inputvalue, moreover also the and circuit past condition concerned. It issimilar to containing the stored energy part the inductance or theelectric
6、 capacity electric circuit, like electric circuit and so ontrigger, latch, counter, shift register, reservoir all is the sequencecircuit typical component. Digital circuit characteristic: 1st, simultaneously has the arithmetic operation and the logicoperation function The digital circuit is take the
7、 binary system logic algebra asmathematics foundation, the use binary numeral signal, both can carryon the arithmetic operation and to be able conveniently to carry onthe logic operation (with, or, non-, judgement, comparison, processingand so on), therefore extremely suits to application and so ono
8、peration, comparison, memory, transmission, control, decision-making. 2nd, realization simple, the system is reliable By binary system underlie numeral logic circuit, simplereliable, the accuracy is high. 3rd, integration rate high, the function realization is easy Integration rate high, volume smal
9、l, the power loss is low isone of digital circuit prominent merits. Electric circuit design,service, maintenance nimble convenient, along with the integratedcircuit technology high speed development, the numeral logic circuitintegration rate is more and more high, integrated circuit blockfunction al
10、ong with small scale integration electric circuit (SSI),center scale integrated circuit (MSI), large scale integrated circuit(LSI), ultra large scale integrated circuit (VLSI) the developmentalso from the part level, the component level, the part level, theboard card level rises to the system level.
11、 The electric circuitdesign composition only must use some standards the integrated circuitblock unit connection to become. Also may use the programmableforeword logic array electric circuit regarding the non- standardspecial electric circuit, through programming method realization freelogic functio
12、n. Digital circuit application: Digital circuit and numeral electronic technology widespreadapplication to science and technology each domain and so ontelevision, radar, correspondence, electronic accounting machine,automatic control, astronautics. 数字电路定义： 用数字信号完成对数字量进行算术运算和逻辑运 算的电路称为数字电路，或数字系统。由于它具
13、有逻辑运算和逻辑处理功能，所以又称数字逻辑电路。 数字逻辑电路分类（按功能分）： 1、组合逻辑电路 简称组合电路，它由最基本的的逻辑门电路组合而成。特点是：输出值只与当时的输入值有关，即输出惟一地由当时的输入值决定。电路没有记忆功能，输出状态随着输入状态的变化而变化，类似于电阻性电路，如加法器、译码器、编码器、数据选择器等都属于此类。 2、时序逻辑电路 简称时序电路，它是由最基本的逻辑门电路加上反馈逻辑回路（输出到输入）或器件组合而成的电路，与组合电路最本质的区别在于时序电路具有记忆功能。时序电路的特点是：输出不仅取决于当时的输入值，而且还与电路过去的状态有关。它类似于含储能元件的电感或电容的
14、电路，如触发器、锁存器、计数器、移位寄存器、储存器等电路都是时序电路的典型器件。 数字电路的特点： 1、 同时具有算术运算和逻辑运算功能 数字电路是以二进制逻辑代数为数学基础，使用二进制数字信号，既能进行算术运算又能方便地进行逻辑运算（与、或、非、判断、比较、处理等 ），因此极其适合于运算、比较、存储、传输、控制、决策等应用。 2、 实现简单，系统可靠 以二进制作为基础的数字逻辑电路，简单可靠，准确性高。 3、集成度高，功能实现容易 集成度高，体积小，功耗低是数字电路突出的优点之一。电路的设计、维修、维护灵活方便，随着集成电路技术的高速发展，数字逻辑电路的集成度越来越高，集成电路块的功能随着小规模集成电路（ SSI）、中规模集成电路（ MSI）、大规模集成电路（ LSI）、超大规模集成电路（ VLSI）的发展也从元件级、器件级、部件级、板卡级上升到系统级。电路的设计组成只需采用一 些标准的集成电路块单元连接而成。对于非标准的特殊电路还可以使用可编程序逻辑阵列电路，通过编程的方法实现任意的逻辑功能。 数字电路的应用： 数字电路与数字电子技术广泛的应用于电视、雷达、通信、电子计算机、自动控制、航天等科学技术各个领域。
