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1、余卫宇一、负反馈放大电路的方框图二、负反馈放大电路放大倍数的一般表达式三、深度负反馈的实质四、深度负反馈条件下放大倍数的估算方法Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.余卫宇决定反馈量和输出量关系的所有元件所组成的网络反馈组态反馈组态电压串联电压串联电压并联电压并联电流串联电流串联电流并联电流并联负反馈放大电路的基本放大电路反馈网络方框图中信号是单向流通的。Evaluation only.Created wi
2、th Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.余卫宇基本放大电路的放大倍数(开环增益）反馈系数反馈放大电路的放大倍数（闭环增益）Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.余卫宇环路放大倍数反馈组态功能电压串联电压控制电压电压并联电流控制电压电流串联电压控制电流电流并联电流控制电流Ev
3、aluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.余卫宇净输入量可忽略不计(a)电路引入负反馈(b)电路引入正反馈( c)电路没有反馈闭环放大倍数AF只取决于反馈系数FEvaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.余卫宇1. 电压串联负反馈电路
4、Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.余卫宇Rif很小Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.余卫宇Evaluation only.Created with Aspose.Slides for .NET 3.5 Clien
5、t Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.余卫宇Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.余卫宇Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.余卫宇反馈组态反馈组态电压
6、串联电压串联电压并联电压并联电流串联电流串联电流并联电流并联Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.余卫宇+ +_ _ _+ + + +_ _u uF F比较两电路比较两电路Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.余卫宇1.
7、第三级从射极输出；2.若在第三级的射极加旁路电容，且在输出端和输入端跨接一电阻。R REvaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.余卫宇因为uO为有限值，Aod，所以uNuP0，即因为rid，所以 理想运放参数特点：Aod，rid，ro0。电路特征：反馈网络为无源网络，如图。uNuP虚短路iNiP0虚断路求解放大倍数的基本出发点Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.余卫宇Evaluation only.Created with Aspose.Slides for .NET 3.5 Client Profile 5.2.0.0.Copyright 2004-2011 Aspose Pty Ltd.
