| 摘要 |
PROBLEM TO BE SOLVED: To provide an isolation circuit for analog information using a photocoupler of one channel that can simultaneously transmit digitally-informatized one-bit binary data and clock. SOLUTION: A PWM encoder 13 uses a PWM method for transmitting one-bit binary data by matching the rise of a clock with that of a PWM signal by generating a pulse having binary pulse widths, that is, a pulse width "T/4" to a code "0" of the one-bit binary data by a clock in a prescribed period T and a pulse width "3T/4" to a code "1" of the one-bit binary data by the clock, in a prescribed period T in the transmission side chip 10. A PWM decoder 23 detects data at timing of "T/2" from the rising of the clock in the reception side chip 20. Accordingly, it has a temporal margin of "T/4". Namely, digital data can be reproduced and outputted on the receiving side, since the data are transmitted with the pulse width and clock information is transmitted with the rise of the pulse simultaneously with a single channel from the transmission side, respectively. COPYRIGHT: (C)2007,JPO&INPIT
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