Method for controlling NFC tag and controlled NFC tag

A controlled near field communication (NFC) tag for pairing with a bluetooth headset, comprising:

• an NFC tag body, comprising an NFC tag chip and an NFC antenna coil;
• an electronic switch, comprising a first connection terminal, a second connection terminal and a control terminal, the first connection terminal and the second connection terminal being connected with two terminals of the NFC antenna coil, respectively;
• an electronic switch control circuit, comprising an input terminal and an output terminal for an enabling or disabling signal, the output terminal being connected with the control terminal of the electronic switch,
• wherein the electronic switch control circuit comprises a booster circuit so as to input the off control signal or the on control signal causing the electronic switch to open or to close, wherein,
• when the enabling or disabling signal is input from the input terminal of the electronic switch control circuit, the output terminal of the electronic switch control circuit outputs an off control signal or an on control signal in response, and the off control signal or the on control signal is exerted upon the control terminal of the electronic switch, so that the first connection terminal and the second connection terminal of the electronic switch are disconnected or connected correspondingly, wherein
• when the off control signal is exerted upon the control terminal of the electronic switch, and the first connection terminal and the second connection terminal of the electronic switch are disconnected, electromagnetic energy coupled with the NFC antenna coil is transferred to an NFC tag chip of the NFC tag so as to enable wireless communication between a NFC card reader and the NFC tag, and
• when the on control signal is exerted upon the control terminal of the electronic switch, and the first connection terminal and the second connection terminal of the electronic switch are connected, the NFC antenna coil is short-circuited, and the electromagnetic energy coupled with the NFC antenna coil is not transferred to the NFC tag chip of the NFC tag so as to disable the wireless communication between the NFC card reader and the NFC tag, such that information stored in the NFC tag chip is not read by the NFC card reader,
• wherein the enabling signal is a non-zero voltage signal, and the disabling signal is a 0V voltage signal, and
• wherein the electronic switch is a normally-closed switch.