Patent ID: 7000040

Claim:
A data receiving apparatus for receiving and demodulating data modulated in a pseudo-ternary form which is transferred over signal line pair in which a transformer is inserted, the data modulated in the pseudo-ternary form taking either of the three values: a first value by which current is allowed to flow in a positive direction in the transformer; a second value by which current is allowed to flow in a negative direction in the transformer; and a third value by which no current is allowed to flow in the transformer, comprising: a first comparator configured to make a comparison between potentials on the paired signal lines connected with the secondary winding of the transformer to produce a signal indicating whether data of the first value has been received or not; a second comparator configured to make a comparison between potentials on the paired signal lines connected with the secondary winding of the transformer to output a signal indicating whether data of the second value has been received or not; a first detector configured to sample the output signal of the first comparator at regular sampling intervals and to compare the value of the current sample with the value of a sample of one sampling interval before to produce a signal indicating whether an output signal indicating the reception of data of the first value has been produced from the first comparator; a second detector configured to sample the output signal of the second comparator at the regular sampling intervals and to compare the value of the current sample with the value of a sample of one sampling interval before to produce a signal indicating whether an output signal indicating the reception of data of the second value has been produced from the second comparator; and an output circuit connected to receive the output signals of the first and second detectors, configured to produce demodulated data corresponding to the data modulated in the pseudo-ternary form.