Digital Isolator Interface with Process Tracking

A method for transmitting a signal through an isolation barrier comprising:

• converting a digital signal to a fast differential edge modulation;
• passing the fast differential edge modulation through a capacitive isolation barrier;
• and
• differentiating the passed fast differential edge modulation to form the pulse according to a transfer function that amplifies the pulse whereby capacitor size in the isolation barrier is reduced or minimized and slowly moving common-mode components that are converted to differential due to capacitor mismatch are attenuated.

A method for transmitting a signal through an isolation barrier comprising:

• forming a plurality of inter-level metal dielectric capacitors on first and second sides of the isolation barrier from respective separate first and second integrated circuit dies from adjacent portions of a common wafer;
• converting a digital signal to a fast differential edge modulation that tracks process characteristics across the isolation barrier;
• and
• passing the fast differential edge modulation through the isolation barrier.

A method for constructing a signal isolator comprising:

• forming first and second separate dies from a common wafer;
• separating the first and second dies by an isolation barrier;
• forming a converter on the first die configured to convert a digital signal to a fast differential edge modulation that tracks process characteristics across the isolation barrier;
• and
• forming a differentiator on the second die in a configuration that differentiates the fast differential edge modulation to form a pulse according to a transfer function that amplifies the pulse.

A signal interface comprising:

• an isolation barrier;
• a converter coupled to the isolation barrier and configured for receiving a digital signal and converting the digital signal to a fast differential edge modulation that tracks process characteristics across the isolation barrier;
• and
• a differentiator coupled to the isolation barrier and configured for receiving the fast differential edge modulation passed through the isolation barrier and differentiating the passed fast differential edge modulation to form a pulse according to a transfer function that amplifies the pulse.

A signal interface comprising:

• an integrated circuit substrate;
• an isolation barrier formed by at least two interlayer metal dielectric capacitors that isolate a first domain from a second domain in the substrate;
• a converter in the first domain coupled to the isolation barrier and configured to convert a digital signal to a fast differential edge modulation that tracks process characteristics across the isolation barrier and pass the fast differential edge modulation across the isolation barrier;
• and
• a differentiator in the second domain coupled to the isolation barrier and configured to differentiate the passed fast differential edge modulation to form a pulse according to a transfer function that amplifies the pulse.