Signal isolator with three state data transmission

A method implementing a signal isolator having a first circuit separated from a second circuit by an isolation barrier layer, the method comprising:

• receiving an input signal at an input of the first circuit of the signal isolator, the input having a logical high or a logical low value;
• providing an output signal at an output of the second circuit as at least one of three states, wherein a first state is indicative of the logical high of the input signal, a second state is indicative of the logical low of the input signal, and a third state is indicative of a first condition, wherein the first circuit is disposed on a first die and the second circuit is disposed on a second die, different from the first die;
• and
• comparing the output of the second die to the input of the first die to provide a compared output.

A method implementing a signal isolator having a first circuit separated from a second circuit by an isolation barrier, the first circuit having a first input and a first output, the second circuit having a second input and a second output, the method comprising:

• receiving an input signal at the first input of the first circuit;
• sending an output signal at the second output of the second circuit back, across the isolation barrier, to a comparison circuit;
• comparing the output signal to the input signal by the comparison circuit;
• and
• providing an output as one of at least three states, wherein a first state is indicative of a logical high of the input signal, a second state is indicative of logical low of the input signal, and a third state indicative of a fault condition when the output signal is not equal to the input signal,
• wherein the first circuit is disposed on a first die and the second circuit is disposed on a second die, different from the first die.