Hi All,

I designed a butter-worth 4th order filter with Fc = 3.5KHz,

I wish to use the part OP496GS.

For verification of the design I acquired the psice model of the part OP196.

I am using Multisim 10.1 for simulation of my circuit.

When I am doing…

AN-581_cn.pdf

参考ADI 应用笔记AN_581《单电源应用中的偏置和去耦运算放大器》设计直流耦合电池供电电路，在P6底部提到电路中 RA,RB电阻阻值的选择需要查看AD663A 数据手册，我查过后发现没有AD663A这款芯片，AD6634/6635/6636是已经停产了的模数转换器，数据手册中也没看到这一部分的内容，这个要怎么解决呢？

问题2：该电路中，使用了一个跟随器电路，它是起隔离的作用吗？但是为什么反相端和输出端之间连接了一个110k欧姆的电阻呢？

Hi, i would like to know the OP296 input resistance. I was wondering if the OP296 works as a transimpedance amplifier with a 1M feedback resistance (so i need that value). any advice?.

And the same question for ADA4528.

Thanks.