RECTIFIER AND LIMITER CIRCUIT CONTROLLED BY SWITCHING SIGNALS, AND PASSIVE RADIO FREQUENCY TAG

摘要

The present invention relates to the technical field of radio frequency identification, in particular to a rectifier and limiter circuit controlled by switching signals and a passive radio frequency tag comprising the rectifier and limiter circuit. The rectifier and limiter circuit controlled by switching signals provided by the present invention converts DC signals, which are absorbed and rectified by an inductance coil antenna of a passive RFID tag, into high- and low-level signals and inputs the high- and low-level signals into the control input terminals of discharge paths of a rectifier circuit. The discharge paths are controlled to be opened or closed according to the amount of charge. The amplitude limiting control of the circuit voltage is realized by dynamically adjusting the voltage amplitude of a rectifier, thereby meeting the requirements on reliability of over-voltage protection of a semiconductor device on a chip and avoiding saturation of reception at the card reader side.

主权项

1. A rectifier and limiter circuit controlled by switching signals, characterized in that the circuit comprises:
a resonant capacitor, which is connected, between a first antenna terminal and a second antenna terminal, in parallel to a resonant inductor, and configured to form a resonant circuit together with the resonant inductor, receive an external electromagnetic field and couple the external electromagnetic field to a rectifier circuit; a rectifier circuit, the input terminal of which is connected to a first antenna terminal and a second antenna terminal and configured to convert AC power, to which the resonant circuit is coupled, into DC power, the first output terminal of which outputs the DC power to an external load circuit, the second output terminal of which outputs the DC power to power supply voltage detection and judgment circuits and is configured to supply a judgment voltage to the power supply voltage detection and judgment circuits, and the third output terminal of which is grounded by at least two N-type MOS transistors connected in parallel to serve as a discharge path and configured to output charge to the ground when the field intensity is too high; and at least two power supply voltage detection and judgment circuits, the power input terminals of which are connected to the second output terminal of the rectifier circuit, and the output terminals of which are connected to the control input terminals of at least two discharge paths of the rectifier circuit and configured to control the discharge paths of the rectifier circuit to be opened or closed according to the amount of charge between the first antenna terminal and the second antenna terminal, so as to control the leakage state of the output terminals.