So, the whole idea is to use base and emitter of the VAS stage transistor to input differential and common mode signal.
Or other words, split differential and common mode signals in voltage and current domains independently.
I1 can be just dedicated winding with ~10-20 pF capacitance to earth/common mains.
But really this task are better to resolve with much more common ways from differential signaling.
In your case just I1 injection aka source/sink can be used to manage common mode.
Or other words, split differential and common mode signals in voltage and current domains independently.
I1 can be just dedicated winding with ~10-20 pF capacitance to earth/common mains.
But really this task are better to resolve with much more common ways from differential signaling.
In your case just I1 injection aka source/sink can be used to manage common mode.