| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a semiconductor device which is normally operated and has high reliability even in the case where a signal having high amplitude is supplied to the semiconductor device having a wireless communication function. <P>SOLUTION: The semiconductor device includes an antenna 101 which generates AC voltage, a rectifier circuit 102 which rectifies the AC voltage and generates internal voltage Vin, a first protection circuit 107, and a second protection circuit 108. The first protection circuit 107 includes a first diode 201 and a second diode 202, and the second protection circuit 108 includes a capacitor 203 and a transistor 204. When the absolute value of the AC voltage generated in the antenna 101 is larger than a certain value, the first protection circuit 107 cuts the surplus, the second protection circuit 108 functions when the level of the internal voltage Vin generated in the rectifier circuit 102 is high, and by changing resonant frequency, the second protection circuit 108 can decrease the number of signals input to the semiconductor device. <P>COPYRIGHT: (C)2010,JPO&INPIT |
