Limiter circuit capable of continuously adjusting amplitude of rectified signal and passive radio frequency tag

A limiter circuit capable of continuously adjusting amplitude of a rectified signal, comprising:

• 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, and receive an external electromagnetic field and couple the external electromagnetic field to a rectifier circuit;
• a rectifier circuit, an input terminal of which is connected to the first antenna terminal and the second antenna terminal, and configured to convert AC power, to which the resonant circuit is coupled, into DC power and output the DC power to an external load circuit, and provide power supply to the rectifier circuit;
• and meanwhile, one output terminal of which is grounded and configured to output charge to the ground when the field intensity is too high;
• and
• a limiter circuit, the power input terminal of which is connected to a power output terminal of the rectifier circuit, and the output terminal of which is connected to a control input terminal of the rectifier circuit;
• wherein the limiter circuit comprises a current mirror unit connected to a power supply;
• a control terminal of the current mirror unit is connected to an input terminal of a threshold unit;
• the control terminal of the threshold unit is connected to a band-gap reference voltage module unit;
• and an output terminal of the threshold unit is grounded;
• the current mirror unit comprises a first P-type MOS transistor and a second P-type MOS transistor;
• sources of the first P-type MOS transistor and the second P-type MOS transistor are respectively connected to the power supply to serve as a current source;
• a gate of the first P-type MOS transistor is connected to a gate of the second P-type MOS transistor;
• the gate of the first P-type MOS transistor is connected to the drain thereof and to the threshold unit;
• and a control terminal of the threshold unit is connected to the band-gap reference voltage module unit, and the output terminal of the threshold unit is grounded;
• and
• a drain of the second P-type MOS transistor is connected to the gate of the first N-type MOS transistor, and grounded by a resistor.