| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique for realizing stable data communication between a data carrier driver and a data carrier device while maintaining a compact and inexpensive configuration intact in a two-contact scheme data communication system.SOLUTION: In this data communication system, a data carrier driver communicating with a data carrier device using a rectification smoothing circuit in order to generate a power supply voltage controls the pulse width of each pulse of a clock signal (pulse voltage) supplied to the data carrier device. The data carrier driver sets the time width of each pulse of the pulse voltage in order to suppress a level reduction occurring in the pulse voltage generated by the data carrier driver itself as will be caused to occur by a charge operation of the rectification smoothing circuit. Specifically, the data carrier driver sets the time width of each pulse of the pulse voltage so that a period in which the pulse voltage is at high level is longer than or equal to a period in which the pulse voltage is at low level in one cycle. |
