As I followed the application note and the datasheet to test the real rms-to-dc converter circuit, I first chose the AD8436 because of its high operating frequency. However the simulation in LTspice always come the similar errors no matter which circuit I use. For example, I use the AD8436 circuit shown in the datasheet as below:
And here is my simulation circuit and error comes along:
This is not the only circuit I tried with AD8436, but also the circuit in the application note. In addition to AD736, but the same error comes along, really don't know why it keeps saying the floating connection. Hope ot hear from you. Thanks a lot.