Walt Kester and James Bryant
Analog Isolation Techniques
There are many applications where it is desirable, or even essential, for a sensor to have no direct (“galvanic”) electrical connection with the system to which it is supplying data. This might be in order to avoid the possibility of dangerous voltages or currents from one half of the system doing damage in the other, or to break an intractable ground loop. Such a system is said to be “isolated,” and the arrangement that passes a signal without galvanic connections is known as an isolation barrier.
The protection of an isolation barrier works in both directions, and may be needed in either, or even in both. The obvious application is where a sensor may ...