| 摘要 |
<p>A code generator is provided which produces a transmission code in response to a serial binary data stream applied to its input (1). The transmission code is similar to that known as WAL2 but whereas WAL2 involves a double frequency component when the binary data changes from "1" to "0" or vice versa the transmission code produced by the code generator holds the output signal constant at a level intermediate those corresponding to the binary "1" and "0". This reduces the high frequency content of the transmitted signal and consequently reduces crosstalk between channels.</p><p>The code generator comprises a first current source (11) which is connected to a summing network (R1) through a first switch (T1, T3), a second current source (12) which is connected to the summing network (R1) through a second switch (T2, T4) and a control circuit (1-14) which produces signals on lines (13,14) to selectively operate the first and second switches.</p> |
