Patent ID: 7339480

Claim:
A power processing interface for a radio frequency identification system, comprising: a resonance circuit for inducing a first signal transmitted from a terminal as an AC voltage; a first rectifier circuit electrically connected to said resonance circuit for converting said AC voltage into a DC voltage; a filter circuit electrically connected to said first rectifier circuit for generating an operating voltage in response to said DC voltage; a voltage-detecting circuit electrically connected to said filter circuit and said first rectifier circuit for detecting a magnitude of said operating voltage; a second rectifier circuit electrically connected to said resonance circuit; and a voltage-clamping modulation circuit electrically connected to said first rectifier circuit, said voltage-detecting circuit and said second rectifier circuit for controlling a conduction of said second rectifier circuit in response to an output of said voltage-detecting circuit so as to bypass an excessive current, and for providing a minimum voltage to said radio frequency identification system during a modulation process so as to keep said radio frequency identification system in a normal operation.