Data transmission method and a data transmission apparatus between ground-isolated apparatuses

1 . A digital data transmission method for transmitting digital data and a clock from a first apparatus to a second apparatus ground-isolated from said first apparatus, said method comprising:

generating reference signals from a power source voltage of said first apparatus and a ground of said first apparatus;

generating a multiphase clock having the same base frequency as the maximum base frequency of said digital data of said clock;

comparing said digital data and said reference signals and outputting the comparison results; and

latching said comparison results using said multiphase clock.

2 . A digital data transmission apparatus that transmits digital data and a clock from a first apparatus to a second apparatus ground-isolated first apparatus from said first apparatus, said transmission apparatus comprising:

a signal generator that generates said reference signals from a power source voltage of said first apparatus and a ground of said first apparatus;

a multiphase clock generator having the same base frequency as the maximum base frequency of said digital data from said clock;

a comparator for comparing said digital data and said reference signals; and

a latching device for latching the comparison results of said comparator using said multiphase clock.

3 . The digital data transmission apparatus according to claim 2 , wherein said first apparatus comprises said signal generator and said second apparatus comprises said comparator.

4 . The digital data transmission apparatus according to claim 2 , wherein said signal generator divides between said power source voltage and said ground of said first apparatus by a resistor to generate said reference signals.

5 . The digital data transmission apparatus according to claim 2 , wherein signal generator divides between the high level and the low level of said digital data by a resistor to generate said reference signals.

6 . A transmitter which comprises:

a data generator for generating digital data in synchronization with a clock; and

a voltage generator for generating threshold voltage corresponding to said digital data and said clock; wherein said transmitter thereafter transmits said clock, said digital data, and said threshold voltage.

7 . The transmitter according to claim 6 , further comprising a device for dividing this clock into a multiphase clock, wherein said transmitter transmits said multiphase clock having the same base frequency as the maximum base frequency of said digital data in place of said clock.

8 . A receiver which receives a clock, digital data and threshold voltage, wherein said receiver comprises:

a first comparator that compares said clock and said threshold voltage;

a second comparator that compares said digital data and said threshold voltage; and

a sampler that samples the second output signals from said second comparator in response to the first output signals from said first comparator, wherein said sampler thereafter outputs sampled signals from said sampler.

9 . The receiver according to claim 8 , wherein said clock is a multiphase clock having the same base frequency as the maximum base frequency of said digital data and said sampled signals are output selectively in response to said multiphase clock.

10 . A digital data transmission apparatus which comprises:

a transmitter which comprises: a data generator for generating digital data in synchronization with a first clock; and a voltage generator for generating first threshold voltage corresponding to said first digital data and said first clock; wherein said transmitter thereafter transmits said first clock, said first digital data, and said first threshold voltage; and

a receiver which receives a second clock, a second digital data and a second threshold voltage, wherein said receiver comprises: a first comparator that compares said second clock and said second threshold voltage;a second comparator that compares said second digital data and said second threshold voltage; and a sampler that samples the second output signals from said second comparator in response to the first output signals from said first comparator, wherein said sampler thereafter outputs sampled signals from said sampler.