Inductive coupling reader comprising means for extracting a power supply voltage

  • US 7,665,664 B2
  • Filed: 12/13/2005
  • Issued: 02/23/2010
  • Est. Priority Date: 08/23/2005
  • Status: Active Grant
First Claim
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1. A method for supplying a power supply voltage to a contactless integrated circuit reader that is in a passive operating mode, in the presence of an external alternating magnetic field, the reader comprising an antenna circuit having at least one input terminal, at least one capacitor and an antenna coil having two end terminals, the antenna circuit being substantially tuned to a working frequency and having, as measured with respect to the at least one input terminal and at the working frequency, a first impedance, the method comprising:

  • taking off in the antenna circuit an alternating voltage induced in the antenna circuit by the external magnetic field; and

    rectifying the alternating voltage to supply an auxiliary supply voltage of the reader.

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