电子线路 差分放大器和差问题练习题题

来源：蜘蛛抓取(WebSpider) 时间：2011-09-04 22:52 标签： 和差问题练习题
使用运放的差分放大器电路图_中国百科网
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使用运放的差分放大器电路图
Differential amplifier.Differential amplifier is a closed loop amplifier circuit which amplifies the difference between two signals. Such a circuit is very useful in instrumentation systems. Differential amplifiers have high common mode rejection ratio (CMRR) and high input impedance. Differential amplifiers can be made using one opamp or two opamps. Both of these configurations are explained here.Differential amplifier using one opamp.The circuit diagram of a differential amplifier using one opamp is shown below. R1 and R2 are the input resistors, Rf is the feedback resistor and RL is the load resistor.Differential amplifier using one opampDerivation for voltage gain.Equation for the voltage gain of the differential amplifier using one opamp can be derived as follows. The circuit is just a combination of an inverting and non inverting amplifier. Finding the output voltages s of these two configurations separately and then summing them will result in the overall output voltage.If Vb is made zero, the circuit becomes an inverting amplifier. The output voltage Voa due to Va alone can be expressed using the following equation.When Va is made zero the circuit becomes a non inverting amplifier. Let V1 be the voltage at the non inverting input pin. Relation between Vb and V1 can be expressed using the following equation.Output voltage Vob due to Vb alone is according to the equationLet R1 = R2 and R3 =Rf thenThen overall output voltage isTherefore overall gain isDifferential amplifier using two opamps.Circuit diagram of a differential amplifier using two opamps is shown below. Main advantage of differential amplifier with two opamps is that it has increased overall gain. R1 is the input resistor for IC1 and R3 is the input resistor for IC2. Rf is the feedback resistor. Va and Vb are the two input voltages and they are applied to the non inverting inputs of ?IC2 and IC1 respectively. RL is the load resistor. V+ and V- are the positive and negative supply voltages.Differential amplifier using opampDerivation of voltage gain.The equation for the output voltage V1 of the first opamp (IC1) is as follows. V1 and Va are the inputs for the second stage (IC2). Output voltage due to Va ?alone is.Output voltage due to Vb alone isOverall output voltage Vo = Voa + VobLet R1 = R2 and Rf =R1, then we haveTherefore overall voltage gain Av can be expressed using the equationPractical differential amplifier.A practical differential amplifier using uA741 opamp is shown below. With used components the amplifier has a gain of around 5. Remember the equation Av = -Rf/R1. Here Rf = 10K and R1 =2.2K, ?-Rf/R1 = -10/2.2 = -4.54 = ~-5. Negative sign represents phase inversion. Use +/-12V DC ?dual supply for powering the circuit. uA 741 must be mounted on a holder.Practical differential amplifier circuit&&&&&
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课程实验七 模拟电路单元版图设计-差分放大器.doc
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3秒自动关闭窗口差分放大器的电路是什么形式?_百度知道
差分放大器的电路是什么形式?
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baidu.hiphotos.jpg" />输出信号正比于输入信号的差值://c://c.com/zhidao/wh%3D600%2C800/sign=5b026e5cc1cec3fd8b6baf73e6b8f807/8435e5dde74fcc1b9d16fdfa6075.jpg" esrc="http.jpg" target="_blank" title="点击查看大图" class="ikqb_img_alink"><img class="ikqb_img" src="/zhidao/wh%3D450%2C600/sign=f2ae72b22c2//zhidao/pic/item/8435e5dde74fcc1b9d16fdfa6075.baidu://c.hiphotos<a href="http
用运放实现差分放大电路，该如何实现呢
百度图片搜索一下就有了。
差分放大电路有什么用呢？
抗共模干扰能力强，输出与输入成线性关系，用在一些要求较高的场合。
就是有两个输入端的电路。
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差分放大器的相关知识
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正向放大器，差分放大器，测量电路
，以及三者的区别
谢谢！
如果用运放来作这三个电路可以选同一种运放片子。正向放大器是信号从运放的正端输入，差分放大器是信号从正负两端同时输入。测量电路一般是差分放大器因为它有高的共模抑制，当然也有专门的测量电路电路，其实就是运放，也是差分放大器，只不过起参数更高，更适合测量使用。
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