Electromagnetic field coupling implementation circuit with safety function for non-contact intelligent card

Abstract

The invention provides an electromagnetic field coupling implementation circuit with a safety function. On one hand, the mechanical electrical connection reliability for card packaging can be improved; on the other hand, the operating risk that the intelligent card of a holder is activated directly and read and written illegally by an attacker through a reader-writer via a magnetic field can be avoided.

Description

technical field [0001] The invention relates to a circuit for implementing electromagnetic field coupling of a non-contact smart card with a safety function, which is mainly used in electronic devices that obtain energy and signals through electromagnetic fields, and for passive radio frequency chips that obtain energy and signals in electromagnetic fields through non-contact methods. The method realizes one-way and two-way transmission of energy and signals, and is especially suitable for the field of non-contact smart cards that realize energy and signal transmission through magnetic field coupling. Background technique [0002] The wide application of smart cards has developed from the initial contact smart card with a single communication interface to the contact and non-contact dual-interface smart cards that are widely used now. The contact communication interface realizes the card reader and smart card through the mechanical and electrical connection of contact contac...

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Problems solved by technology

[0002]The wide application of smart cards has developed from the initial contact smart card with a single communication interface to the contact and non-contact dual-interface smart cards that are widely used now. The contact communication interface is through The mechanical and electrical connection of the contact point realizes the power supply and signal transmission between the card reader and the smart card; the non-contact communication interface usually uses inductive coupling to realize the transmission of energy and signals, and the smart card using inductive coupling is usually composed of The resonant inductor, resonant capacitor, and electronic module are composed of the resonant inductor and the resonant capacitor that form a parallel resonance, and are electrically connected to the port of the electronic module by welding. This method has two obvious weaknesses: one is the resonance The welding of the inductor and the electronic module has a weakness in the reliability of the mechanical connection, and there is a possibility of welding open circuit under stress conditions such as card twisting and deformation; on the other hand, as a smart card used in the security field, when the cardholder is unknown Under the circumstances, the attacker can easily use the magnetic field of the card reader to activate the smart card and put it in a charged state, so as to further attack the possibility

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