Patent ID: 7768790

Claim:
An electronic communications circuit comprising: a first substrate including a first coil that is formed by wiring on the first substrate, and is connected to a transmitter circuit having a delay element; a second substrate including a second coil that is formed by wiring on the second substrate at a position corresponding to said first coil, is inductively coupled to said first coil, and is connected to a first receiver circuit; and a third substrate including a third coil that is formed by wiring on the third substrate at a position corresponding to said first and second coils, is inductively coupled to said first and second coils, and is connected to a second receiver circuit; said substrates being laminated in order from said first substrate to said third substrate, wherein said transmitter circuit changes a potential of one end of said first coil from a first potential to a second potential in response to a change of a transmission digital signal from zero to one, changes a potential of the other end of said first coil from said first potential to said second potential in a predetermined delay, changes a potential of said one end of said first coil from said second potential to said first potential in response to a change of said transmission digital signal from one to zero, and changes a potential of said other end of said first coil from said second potential to said first potential in a predetermined delay; and said first and second receiver circuits receive a digital signal transmitted by said transmitter circuit.