选择正确的德州仪器信号开关

摘  要
德州仪器提供各式各样的电子开关 (数传，类比, 双边的,双边的类比) 在多种家庭中, 包括 CBT 、 CBTLV 、 HC 、 LV 和 LVC。 靠在申请上，正确的解决可能是一个经过数传信号的类比开关, 或反之亦然。 这一项申请报告概述各种不同的转变技术和提供选择适当的 TI 信号开关的申请考量。

1  引言
德州仪器提供多种家庭的各式各样的信号开关，包括 CBT、CBTLV 、 CD4000 、 HC，LV-一, 和 LVC。 这些信号开关可能是数字，模拟， 双边的或双边的模拟。 选择正确的可能是一件强大的工作。 这一个申请的目的报告将藉由举例说明在家庭之间的不同使选择处理比较容易而且在命名会中消除不明确。

2  背景(优秀毕业设计 www.2bysj.cn)
首先以开关来看,示意图为理想开关(类似图1 ),或接近理想。
 
输入信号=输出信号
图表1   为理想开关

在图 1 的适用于左边的输入／输出大头针 (或端口) 的一个输入信号在右边的输入／输出大头针造成一个同一的输出信号，和反之亦然。 然而，在真正的世界中，开关不是理想的，而且总是有一些损失。 在干净的情况, 适当地工作机械的开关, 损失是如此微不足道，因而它几乎不忍受注意。
相似的机械开关,使用电晶体的开关也不是理想的。 事实上, 与损失有关的使用电晶体的开关可能是重要的。 为什么使用如果它如此远来自于理想，一个开关喜欢这? 答案是方便。使用电晶体的开关小、快速、以及容易使用, 容易的控制,而且消费被与传统的电受约束的开关, 像是接替者相较的相对一点的力量。 在这一项申请报告中提及的开关是补充的金属-氧化物的半导体(互补型金属氧化半导体) 领域-效果的电晶体 (FET) 转变。 如先前当, 他们不是理想的，因此，我们需要一个方法调查并且比较表现特性那不同的互补型金属氧化半导体家庭。 图 2 表演一单一化-互补型金属氧化半导体的线路模型转变。
 
BSTRACT
Texas Instruments offers a wide variety of electronic switches (digital, analog, bilateral,bilateral analog) in a variety of families, including CBT, CBTLV, HC, LV, and LVC. Dependingon the application, the right solution may be an analog switch that passes digital signals, orvice versa. This application report summarizes the various switching technologies and rovides application considerations for choosing the appropriate TI signal switch.

1 Introduction
Texas Instruments offers a wide variety of signal switches in a variety of families, including CBT,CBTLV, CD4000, HC, LV-A, and LVC. These signal switches can be digital, analog, bilateral, or lateral analog. Selecting the right one can be a formidable task. The purpose of this application report is to make the selection process easier by illustrating the differences between the families and removing ambiguity in the naming conventions.
2 Background
When first considering switches, a schematic of the ideal switch (similar to Figure 1) might come to mind.
 
Signal In = Signal Out
Figure 1. Ideal Switch
An input signal applied to the left I/O pin (or port) in Figure 1 results in an identical output signal at the right I/O pin, and vice versa. However, in the real world, switches are not ideal and there always is some loss. In the case of clean, properly working mechanical switches, the loss is so miniscule that it hardly bears noting.
Like mechanical switches, solid-state switches are not ideal either. In fact, losses associated with solid-state switches can be significant. Why use a switch like this if it is so far from ideal? The answer is convenience. Solid-state switches are small, fast, easy to use, easy to control,and consume relatively little power compared to traditional electrically controlled switches, such as relays. The switches referred to in this application report are complementary metal-oxide semiconductor (CMOS) field-effect transistor (FET) switches. As mentioned previously, they are not ideal, so we need a way to examine and compare the performance characteristics of the different CMOS families. Figure 2 shows a simplified-circuit model of a CMOS switch.