* Question
| What are the main performance indicators of integrated op amps? |
* Answer
| 1. Open-loop differential mode voltage gain Aud. When there is no external connection between the output terminal and the input terminal of the integrated operational amplifier, the ratio of output voltage to input voltage is defined as open-loop differential mode voltage gain, ie Aud=U0/ui.The larger the open-loop differential mode voltage gain Aud of the integrated op amp, the better the open-loop voltage gain of the ideal op amp, Aud→∞.It reflects the amount of current drawn by the integrated op amp from the source.Define Rid=Uid/Iid.The larger the differential mode input resistance Rid, the better. The differential mode input resistance of the ideal op amp is Rid→∞4 and the output resistance R0.Commonly used decibels, that is, KCMR=20log∣Aud/Auc∣(db) The larger the common mode rejection ratio of the integrated op amp, the better the ideal op amp KCMR→∞6, the maximum common mode input voltage amplitude uicm.Uicm=12V7 of 007, maximum differential mode input voltage amplitude uidm When the differential mode input voltage applied between the two input terminals of the integrated operational amplifier exceeds a certain value, the normal input performance of the input stage is destroyed.
Maximum differential mode input voltage amplitude uidm.The smaller the input offset voltage of the integrated op amp, the better.When the ideal op amp tends to 09 and the input bias current IIB is static, the DC current values of the two inputs are defined as the average of the IB1 and IB2 input bias currents.The Iib of F007 is about 200nA.The smaller the input bias current of the integrated op amp, the better.The bandwidth of the open-loop differential mode voltage gain of the op amp is reduced to 2 times (-3db) of the DC gain, which is called the -3db open-loop gain bandwidth of the op amp, and is represented by BW.The open-loop voltage gain of the op amp drops to a one-time bandwidth, called the unity gain bandwidth, expressed in BWG.The open loop gain bandwidth of an ideal op amp is infinite. |
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