| 摘要 |
<P>PROBLEM TO BE SOLVED: To generate a stable internal power supply even when there is access from a noncontact terminal during contact operation. <P>SOLUTION: The semiconductor device (U2) has a first power supply circuit (B3) which produces a DC voltage on a first power supply line (VDD) based on a voltage applied externally to a power supply terminal (VCC), a rectifier circuit (B4) which rectifies an AC signal provided from an antenna (L0) to antenna terminals (LA, LB), and a second power supply circuit (B5) which produces a DC voltage on the first power supply line based on a rectified voltage. When a voltage is applied to the power supply terminal, the rectifier circuit stops rectification operation. <P>COPYRIGHT: (C)2012,JPO&INPIT |
