Isolator with integral transformer

A method of providing galvanic isolation for one or more signals comprising:

• providing a substrate for supporting isolator circuitry and having a plurality of parallel conductive layers separated by insulation;
• providing a region in the substrate between an upper conductive shield formed in a second conductive layer of the substrate and a lower conductive shield formed in a fifth conductive layer of the substrate,
• forming a first transformer in the region between the upper conductive shield and lower conductive shield including a first primary winding formed in a third conductive layer of the substrate and a first secondary winding formed in a fourth conductive layer of the substrate;
• providing space in the region for a magnetic field coupling the first primary and secondary windings;
• exciting the primary winding at a first frequency using power derived exclusively from a first input signal;
• selectively sensing the first frequency at the secondary winding;
• providing an output signal via a first output in response to sensing the first frequency using power derived from the secondary winding;
• and
• providing encapsulation material covering the electronic components and at least a portion of the upper surface of the substrate.

An apparatus comprising:

• a substrate having a plurality of parallel conductive layers separated by insulation;
• a region formed in the substrate having an upper conductive shield formed in a second conductive layer of the substrate and a lower conductive shield formed in a fifth conductive layer of the substrate,
• a transformer formed in the region between the upper conductive shield and lower conductive shield and including a primary winding formed in a third conductive layer of the substrate and a secondary winding formed in a fourth conductive layer of the substrate;
• the region providing space for a magnetic field coupling the windings;
• a first high frequency oscillator circuit having an input for receiving an input signal, the first oscillator circuit being connected at one end of the substrate to excite the primary winding at a first frequency in response to the input signal;
• a first detector circuit connected at an opposite second end of the substrate to the secondary winding, having a first output, being adapted to selectively sense the first frequency, and being configured to provide an output signal via the first output in response to the first oscillator exciting the primary winding.