| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve data processing efficiency by actualizing control over a clock signal frequency, taking a surplus of a DC current according to a communication distance into consideration with no increase in circuit scale and in a shortened processing time. <P>SOLUTION: The non-contact communication device includes a detection part (5) which detects the extent of the surplus of the DC current, obtained by rectifying a signal input from an antenna terminal (LA, LB), with respect to a source voltage (VDD) generated by a voltage generation part (20) which generates the source voltage from the DC current. A data processing part (6) which performs data processing on transmission and reception signals using the source voltage as an operation voltage includes a clock control part (11) which determines the frequency of a clock signal for the data processing based upon the level of the surplus current detected by the detection part in a state in which the frequency of the clock signal (SCLK) is set to a predetermined reference frequency. Electric power consumed by the data processing part during the surplus detection of the DC current is a power consumption determined by the specific reference frequency, so the detected surplus of the DC current can be grasped as an absolute surplus. <P>COPYRIGHT: (C)2012,JPO&INPIT |
