| 摘要 |
An overvoltage protective circuit for a near-field communication (NFC) or radio frequency identification (RFID) device comprising an NFC of RFID circuit 226, antenna, rectifier 220, switch 224, voltage detector 228 and control module 230, wherein the measured voltage is compared to a threshold value, and if it exceeds this then the control module controls the switch to be open. After a predetermined time period the control module reassesses the input voltage in comparison to the threshold value and changes the position of the switch 224 accordingly. This is done by gradually transitioning the switch to the closed state, and if at any time the voltage detected exceeds the threshold value this is indicated to the control module 230 which then opens the switch 224 again. The antenna 210 may have multiple terminals 214,216 and may therefore comprise multiple rectifiers 222. The antenna may comprise an inductor 202 and capacitor arrangement 208, 212. |
