最近看ADI的应用文档,发现原来自己一直犯了一个错误,就是错误的运用平衡电阻去消减运放偏置电流或者失调电流的影响了!
原文如下: It is also well-known fact that,within an op amp application circuit,the effects of bias current on the output offset voltage of an op amp can be cancelled by making the source resistances at the two inputs equal.But,there is an important caveat here.The validity of this practice only holds true for bipolar input op amps without bias current compensation,that is,where the input currents are well matched.In a case of an op amp using internal bias current compensation,adding an extra resistance to either input will usually make the output offset worse!
那么内部偏置电流补偿的运放比如OP27,OP37如何减小偏置电流或者失调电流的影响呀?? |