What other parameters are important when considering an isolation device?

The ideal isolator consumes no power, imposes no signal errors, and supports any type of input signal. As a result, the important performance metrics are as follows:

Which of the above metrics are important to a particular user is a function of the application in question. Often in a specific application, certain parameters are important and others are not.

Other performance characteristics important to users are an isolator's power-up/down characteristics, its performance in the presence of input noise, and its performance in the presence of a DC input or after a loss of power. In all cases, the output of an isolator should properly reflect the correct input state.