Patent ID: 8339245
Filing Date: 2012-12-25
Classification: G06K,H01Q,H02M

Abstract:
1. A semiconductor device comprising: an antenna; a rectifier circuit electrically connected to the antenna; a first capacitor comprising a first electrode electrically connected to the rectifier circuit, and a second electrode electrically connected to a first ground line; a first switch electrically connected to the first electrode, a second capacitor comprising a third electrode electrically connected to the first switch, and a fourth electrode electrically connected to a second ground line; a second switch electrically connected to the third electrode; a third capacitor comprising a fifth electrode electrically connected to the second switch, and a sixth electrode electrically connected to a third ground line; and a constant voltage circuit, wherein an input terminal of the constant voltage circuit is electrically connected to the rectifier circuit and the first electrode, and an output terminal of the constant voltage circuit is electrically connected to a logic circuit, wherein the first switch and the second switch each comprises a first transistor and a first diode, and one terminal of the first diode is electrically connected to one of source and drain of the first transistor, and the other terminal of the first diode is electrically connected to the other of source and drain of the first transistor, and wherein during charging, the first switch is configured to be turned on after the first capacitor is charged above a predetermined level to charge the second capacitor, and the second switch is configured to be turned on after the second capacitor is charged above a predetermined level to charge the third capacitor; and wherein during discharging, the second switch is configured to be turned off after the third capacitor discharge below a predetermined level of charge, and the first switch is configured to be turned off after the second capacitor is below a predetermined level of charge.