A limiting circuit

Abstract

The invention discloses an amplitude limiting circuit. The amplitude limiting circuit comprises a voltage sampling unit, an amplification unit and an amplitude limiting unit, wherein the amplitude limiting circuit is connected with power voltage to be subjected to amplitude limiting and a bias current generation circuit; the voltage sampling unit converts first bias current which is generated by the bias current generation circuit into sampling voltage by a sampling resistor; the amplification unit amplifies voltage reduction formed between the power voltage and the sampling voltage; and the amplitude limiting unit performs amplitude limiting on the voltage which is amplified by the amplification unit. By adoption of the technical scheme, the technical problems of high deviation and low accuracy of the power voltage which is output by the amplitude limiting circuit in the prior art are solved.

Description

technical field [0001] The invention relates to the field of electronics, in particular to a limiter circuit. Background technique [0002] For electronic devices, when the input voltage is too large or the internal load is too small, the limiter circuit is usually required to discharge the excess energy and limit the power supply voltage. Take the UHF RFID tag chip as an example. When the distance between the tag and the card reader is relatively small When the energy sensed by proximity is too large or the internal load of the chip is too small, the power supply voltage will be too high, which is higher than the normal operating voltage of the device, which will affect the performance of the circuit. A limiting circuit is designed in the circuit, and excess energy is released through the limiting circuit. [0003] The limiter circuit in the prior art is generally implemented by detecting the voltage and incorporating a certain resistive load into the chip system according...

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