CN103413168A - Rectification amplitude limiting circuit of RFID - Google Patents

Abstract

The invention relates to a rectification amplitude limiting circuit of a RFID. The rectification amplitude limiting circuit is characterized in that a first resistor and a second resistor are connected with two input ends respectively to be connected with a substrate bias amplitude limiting module and a rectification module respectively, the rectification module is connected with the substrate bias amplitude limiting module through a voltage monitoring control module, a third resistor and a fourth resistor which are connected with the first resistor and the second resistor respectively are symmetrically arranged in the substrate bias amplitude limiting module, the third resistor and the fourth resistor are connected with two substrate bias control elements respectively through two current discharge elements to be then connected with the ground, and the control ends of the two current discharge elements and the two substrate bias control elements are all connected with the voltage monitoring control module. The rectification amplitude limiting circuit is simple and reliable in structure, can bear the approximate twenty-volt high voltage sensed by an antenna, meanwhile, can produce the minimum rectification output voltage which enables a chip to normally work with the low antenna end sensing voltage only, and accordingly and greatly improves the voltage endurance capability of the RFID under the condition that the longest working distance is not reduced.

Description

The rectification amplitude limiter circuit of radio electronic label

Technical field

The present invention relates to the rectification amplitude limiter circuit, is the rectification amplitude limiter circuit for radio electronic label concretely.

Background technology

Along with the rise of Internet of Things, RFID(radio-frequency (RF) identification) technology has obtained application very widely.The RFID technology is a kind of Modern wireless communication technology of utilizing the space electromagnetic wave to communicate, can realize that the noncontact remote information reads.The RFID technology is compared conventional bar code (barcode) and is had the advantages such as read-write, that read or write speed is fast, security is high.That is used widely at present has low frequency tags (125KHz～134.2KHz), high-frequency label (13.56MHz), ultrahigh-frequency tag (860MHz～960MHz) and microwave segment mark label (2.4GHz～5.8GHz).

The electronic tag that works in different frequency range is referred to as radio electronic label, and it mainly is comprised of antenna, AFE (analog front end), digital processing part and storage unit.The supply voltage of passive label chip is that its magnetic field energy of utilizing the mode of magnetic Field Coupling that reader is sent by antenna is coupled to the connection of antenna receiving end from the electromagnetic wave signal that reader sends, obtaining.The magnetic field changed causes the electric field of alternation on antenna, the antenna of namely capturing electromagnetic energy is equivalent to an AC power, antenna ends is exactly the two ends of AC power, can change the alternating voltage of antenna ends into to chip power supply DC voltage by the rectification module in the label chip AFE (analog front end).Yet the electromagnetic energy that reader sends can sharply change along with the variation of distance, thereby the voltage amplitude variation scope that the electronic label antenna induction obtains is very large, the highest alternating voltage that may induce up to nearly 20 volts.

In order to allow device in rectification module can bear antenna, may respond to the high pressure obtained, the general two schemes that adopts in traditional structure, the one, adopt the input pipe of high voltage bearing device as rectification module, at rectification output end, the effect that leadage circuit reaches the step-down amplitude limit is set, but relative normal pressure Guan Eryan has larger threshold voltage due to high-voltage tube, while causing its rectification, need to expend larger voltage remaining.Namely in the situation that obtain identical rectifier output voltage, its input voltage amplitude needed, than the height that adopts the normal pressure pipe, has reduced the maximum functional distance of chip.In addition, the technique that this method requires to use can provide high-voltage tube, thereby the universality of application is lower; The 2nd, in antenna end, clamp circuit is set, by clamp technical limitation input signal amplitude, but transistor used is numerous, and complex structure, increased use cost.Therefore, above-mentioned traditional method all can not meet the requirement that the radio electronic label telecommute has both low-cost application well.

Summary of the invention

The invention provides a kind of rectification amplitude limiter circuit of radio electronic label, make the antenna end induced voltage that electronic tag only need be lower just can produce the minimum commutation output voltage that chip can be worked, thereby, in the situation that do not reduce operating distance farthest, improve the voltage endurance capability of radio electronic label.

The rectification amplitude limiter circuit of radio electronic label of the present invention, after the first resistance connects first input end and the second resistance connection the second input end, all with the input end of the inclined to one side amplitude limit module of lining and rectification module, be connected, rectification module connects the inclined to one side amplitude limit module of described lining by two output voltage after the voltage monitoring control module, at lining, has the 4th resistance that the 3rd resistance that an end is connected with the first resistance and an end are connected with the second resistance in inclined to one side amplitude limit module, the other end of the 3rd resistance and the 4th resistance by the first earial drainage element, be connected with the second earial drainage element respectively first the lining inclined to one side control element and second the lining inclined to one side control element after ground connection, the control end of the first earial drainage element and the second earial drainage element all is connected a wherein road output voltage of described voltage monitoring control module, the inclined to one side control element of the first lining all is connected another road output voltage of described voltage monitoring control module with the control end of the inclined to one side control element of the second lining.

The present invention utilizes negative-feedback technology in conjunction with body bias effect, output by voltage monitoring control module monitoring rectification module, then produce suitable negative feedback control signal, the lining of regulating the earial drainage element in controlled discharge element conductive power is partially strong and weak, reaching the low pressure amplitude limit weakens, the effect that the high pressure amplitude limit strengthens, realize the accurate control of output to input, thereby make rectifier output voltage be controlled in the scope that subsequent conditioning circuit can work.Wherein rectification module and voltage monitoring control module all can be used existing conventional module.

Preferably, described the first earial drainage element and the second earial drainage element, and first the lining inclined to one side control element and second the lining inclined to one side control element be nmos type transistor;

Corresponding the 3rd resistance and the 4th resistance of being connected of the drain electrode of the first earial drainage element and the second earial drainage element, the corresponding drain electrode that is connected the first inclined to one side control element of lining and the inclined to one side control element of the second lining of the source electrode of the first earial drainage element and the second earial drainage element;

The grid of the first earial drainage element and the second earial drainage element all is connected a wherein road output voltage of described voltage monitoring control module;

The source grounding of the first inclined to one side control element of lining and the inclined to one side control element of the second lining, grid all connects another road output voltage of voltage monitoring control module.

Further, the equal ground connection of substrate of the first earial drainage element of described nmos type transistor structure, the second earial drainage element, the first inclined to one side control element of lining and the inclined to one side control element of the second lining.

Further, described rectification module is for intersecting the bridge rectifier module.The bridge rectifier module of intersecting is existing conventional module, and its structure is not done detailed description at this.

Circuit structure of the present invention is simple and reliable, and when can bearing nearly 20 volts of high pressure that antenna induction arrives, antenna end induced voltage that only need be lower just can produce the minimum commutation output voltage that chip can be worked, thereby, in the situation that do not reduce operating distance farthest, significantly improved the voltage endurance capability of radio electronic label.

Below in conjunction with the embodiment of embodiment, foregoing of the present invention is described in further detail again.But this should be interpreted as to the scope of the above-mentioned theme of the present invention only limits to following example.Without departing from the idea case in the present invention described above, various replacements or change according to ordinary skill knowledge and customary means are made, all should comprise within the scope of the invention.

The accompanying drawing explanation

Fig. 1 is the circuit diagram of the rectification amplitude limiter circuit of radio electronic label of the present invention.

Fig. 2 is a kind of particular circuit configurations of Fig. 1.

Fig. 3 be the input rectifying module of Fig. 2 voltage magnitude (| V _In1-V _In2|) with the antenna induction voltage magnitude (| V _{ANT_A}-V _{ANT_B}|) the simulation waveform figure that changes.

Fig. 4 is the rectifier output voltage (V of Fig. 2 _rec) with the antenna induction voltage magnitude (| V _{ANT_A}-V _{ANT_B}|) the simulation waveform figure that changes.

Fig. 5 is the voltage stabilizing output voltage (V of Fig. 2 _CC) with the antenna induction voltage magnitude (| V _{ANT_A}-V _{ANT_B}|) the simulation waveform figure that changes.

Embodiment

The rectification amplitude limiter circuit of radio electronic label of the present invention as shown in Figure 1, the output voltage of rectification module of take is example near 1.8V.Because of the technique difference, the required supply voltage difference of the chip of design, thus metal-oxide-semiconductor parameter and resistance in the rectification amplitude limiter circuit have difference.For easy to understand, this embodiment will realize controlling voltage V with the simplest circuit _C1And V _C2Obtain.

In Fig. 1, comprised conventional cross bridge rectifier module and voltage monitoring control module, also have the inclined to one side amplitude limit module of lining.The voltage that antenna obtains from the first and second two voltage input end inductions is from V _{ANT_A}And V _{ANT_B}Input, two input end V of rectification module _In1, V _In2Through the first resistance R ₁With the second resistance R ₂With antenna induction signal input part V _{ANT_A}, V _{ANT_B}Correspondence is joined respectively, and produces rectifier output voltage V _recBe linked in the voltage monitoring control module.The voltage monitoring control module is according to its input signal V _recProduce two and V _recRelevant signal V _C1And V _C2As control signal, be input in the inclined to one side amplitude limit module of lining; Serve as a contrast inclined to one side amplitude limit module according to control signal V _C1And V _C2Regulate its current drain ability, reach the purpose of step-down amplitude limit.

As depicted in figs. 1 and 2, at lining, has the 4th resistance R 4 that the 3rd resistance R 3 that an end is connected with the first resistance R 1 and an end are connected with the second resistance R 2 in inclined to one side amplitude limit module, the other end of the 3rd resistance R 3 and the 4th resistance R 4 is connected respectively the first earial drainage element MN1 of being the nmos pass transistor structure and the drain electrode of the second earial drainage element MN2, and by corresponding connection of source electrode of the first earial drainage element MN1 and the second earial drainage element MN2 being similarly the drain electrode that first of nmos pass transistor serves as a contrast inclined to one side control element MN3 and the inclined to one side control element MN4 of the second lining, the source grounding of the first inclined to one side control element MN3 of lining and the inclined to one side control element MN4 of the second lining.The grid of the first earial drainage element MN1 and the second earial drainage element MN2 all is connected a wherein road output voltage V of described voltage monitoring control module _C1, the inclined to one side control element MN3 of the first lining all is connected another road output voltage V of voltage monitoring control module with the grid of the inclined to one side control element MN4 of the second lining _C2.The equal ground connection of substrate of the first earial drainage element MN1, the second earial drainage element MN2, the first inclined to one side control element MN3 of lining and the inclined to one side control element MN4 of the second lining.

In Fig. 2, conventional cross bridge rectifier module is managed MN by NMOS ₅, MN ₆, MN ₇And MN ₈Form, wherein NMOS pipe MN ₅Drain electrode meet the input end V of rectification module _In1, grid meets the input end V of rectification module _In2, source class ground connection.NMOS manages MN ₆Drain electrode meet the input end V of rectification module _In2, grid meets the input end V of rectification module _In1, source class ground connection.NMOS manages MN ₇With NMOS pipe MN ₈Be the diode type of attachment, its grid leak short circuit also meets respectively the input end V of rectification module _In1And V _In2, its source class is received together the output as rectification module.NMOS manages MN ₅, MN ₆, MN ₇And MN ₈The equal ground connection of substrate.The voltage that common antenna induction obtains is sinusoidal signal and its both end voltage V _{ANT_A}And V _{ANT_B}Single spin-echo.Work as V _{ANT_A}For timing NMOS pipe MN ₆And MN ₇Conducting, work as V _{ANT_B}For timing NMOS pipe MN ₅And MN ₈Conducting, and twice conducting all produces the electric current of same phase in load, thus realize full-wave rectification.

In order to facilitate rationale, the voltage monitoring control module in this embodiment is by two resistance R ₅, R ₆And the PMOS of diode type of attachment pipe MP ₁Form.Resistance R ₅The output V of one termination rectification module _rec, another termination PMOS manages MP ₁Source electrode; PMOS manages MP ₁The grid leak short circuit, substrate connects source electrode to eliminate body bias effect, drain electrode connecting resistance R ₆Resistance R ₆Other end ground connection.Control voltage V _C2From PMOS pipe MP ₁Drain electrode draw.By the size of pipe breadth length ratio and resistance value rationally is set, can make when the rectification module output voltage is 1.8V, control voltage V _C2Reach the threshold voltage of the inclined to one side control tube of lining.The inclined to one side control tube NMOS pipe of lining used MN in this embodiment ₃And MN ₄Threshold voltage be 0.7V, PMOS manages MP ₁Threshold voltage is-0.7V.The threshold voltage of supposing pipe does not change with external environment, controls voltage V _C2Be expressed as: V _C2=R ₆/ (R ₅+ R ₆) * (V _rec-V _GSP1), V _GSP1For PMOS pipe MP ₁Gate-source voltage.Want to make to control voltage V _C2Output voltage V at rectification module _recDuring for 1.8V, its value, for the 0.7V left and right, requires R ₆/ (R ₅+ R ₆)=7/11.Accordingly, fixed resistance R ₅After value, just can obtain resistance R ₆Value.Due to above-mentioned calculating, ignored the impact of environment, it is not very accurate, finally also needs, by emulation, each component parameters in circuit is carried out to intense adjustment.Be in course of adjustment and should be noted that the value of resistance, it should not be excessive or too small.Cross conference and take larger area, too smallly can consume too much power.Power taking resistance R in this example ₅For 120K Ω, resistance R ₆For 210K Ω.

Suppose that can make the minimum commutation output voltage values of chip normal operation is V _{Rec_min}, and the minimum voltage amplitude that can produce the rectification module input end of this voltage is V _{In_min}, the antenna end minimum voltage amplitude that corresponding induction obtains is V _{ANT_min}.If the voltage that antenna induction obtains (| V _{ANT_A}-V _{ANT_B}|) be less than V _{ANT_min}, the voltage of rectification module input end (| V _In1-V _In2|) can be less than V _{In_min}, cause rectification output not reach the required minimum commutation output voltage values V of chip _{Rec_min}Thereby label chip can't work.The voltage of sensing when antenna (| V _{ANT_A}-V _{ANT_B}|) be greater than antenna end minimum voltage V _{ANT_min}The time, the rectification module output voltage V of thereupon raising _recAlso be greater than the minimum commutation output voltage V _{Rec_min}, make the access produced by the voltage monitoring control module serve as a contrast the control signal V of inclined to one side amplitude limit module _C1, V _C2Increase.Because the conducting degree of bleeder circuit strengthens with the increase of controlling voltage, thereby flow through the first resistance R ₁With the second resistance R ₂Electric current increase, make the first resistance R ₁With the second resistance R ₂The pressure reduction at two ends increases separately, causes V _In1=V _{ANT_A}– IR ₁And V _In2=V _{ANT_B}– IR ₂Reduce, with this reach restriction rectification module input terminal voltage (| V _In1-V _In2|) big or small purpose.

Due to the voltage of sensing when antenna (| V _{ANT_A}-V _{ANT_B}|) be less than V _{ANT_min}The time, rectification output does not reach the required minimum V of chip _{Rec_min}, therefore the having little significance of its analysis, only illustrate here that voltage that antenna induction arrives is from V _{ANT_min}The situation that starts to increase.The voltage of sensing when antenna is greater than V _{ANT_min}The time, rectifier output voltage V _recAlso with antenna induction voltage (| V _{ANT_A}-V _{ANT_B}|) increase and increase, and surpass V _{Rec_min}.The voltage monitoring control module monitors this variation, produces and controls voltage V _C1, V _C2Be input in the inclined to one side amplitude limit module of lining.Along with controlling voltage V _C2Increase, the bleeder circuit served as a contrast in inclined to one side amplitude limit module is started working.When bleeder circuit is just started working, due to the inclined to one side control element MN of the first lining ₃With the inclined to one side control element MN of the second lining ₄Introducing, the source class current potential of the first earial drainage element MN1 and the second earial drainage element MN2 is high more a lot of than substrate electric potential, makes the first earial drainage element MN1 and threshold voltage V corresponding to the second earial drainage element MN2 _TH1And V _TH2In this case because body bias effect increases, thereby the size of restriction leakage current has been prevented under low pressure the excessively situation of earial drainage.Yet, in the situation that the voltage that antenna induction arrives is higher, the inclined to one side control element MN of the first lining ₃With the inclined to one side control element MN of the second lining ₄Can be owing to controlling voltage V _C2Increase, make its conducting resistance sharply reduce, the body bias effect of the first earial drainage element MN1 and the second earial drainage element MN2 sharply weakens, thereby can not affect the processing of this circuit to high-pressure situations.Control voltage V _C2For controlling the inclined to one side control element MN of the first lining ₃With the inclined to one side control element MN of the second lining ₄Open and make it to be operated in linear zone.The NMOS pipe that works in linear zone can be equivalent to a variable resistor, and its value is:

$R_{\mathrm{on}}=\frac{1}{{\mathrm{\μ}}_n{C}_{\mathrm{ox}}\frac{W}{L}(V_{\mathrm{GS}}-V_{\mathrm{TH}})}=\frac{1}{{\mathrm{\μ}}_n{C}_{\mathrm{ox}}\frac{W}{L}(V_{c2}-V_{\mathrm{TH}\mathrm{3,4}})}$ (formula 1)

μ in formula 1 _nAnd C _OxBe parameter,

For the wide and long ratio in NMOS pipe trench road, V _GSFor NMOS pipe gate-source voltage, V _THFor desired threshold voltage, V _TH3,4Be the inclined to one side control element MN of the first lining ₃Or the inclined to one side control element MN of the second lining ₄Threshold voltage (first the lining inclined to one side control element MN ₃With the inclined to one side control element MN of the second lining ₄Threshold voltage identical, appoint and to get one).

Can find out variable resistor R _OnWith controlling voltage V _C2Increase and reduce.The source class of leak-off pipe (also namely serving as a contrast the drain electrode of inclined to one side control tube) current potential is:

${\mathrm{<figure-callout\; id="1"\; label="V\; S"\; filenames="HDA0000368661100000021.png,HDA0000368661100000022.png"\; state="\{\{state\}\}">\; <figure-callout\; id="2"\; label="V\; S"\; filenames="HDA0000368661100000022.png,HDA0000368661100000032.png"\; state="\{\{state\}\}">V</figure-callout>\; </figure-callout>}}_S=I_D{R}_{\mathrm{on}}=\frac{I_D}{{\mathrm{\&mu;}}_n{C}_{\mathrm{ox}}\frac{W}{L}(V_{\mathrm{GS}}-V_{\mathrm{TH}})}=\frac{I_D}{{\mathrm{\&mu;}}_n{C}_{\mathrm{on}}\frac{W}{L}(V_{c2}-V_{\mathrm{TH}\mathrm{3,4}})}$ (formula 2)

I in formula 2 _DFor drain current.Can find out source class current potential V _S1,2Also with control signal V _C2Increase and reduce.Because the equal ground connection of the substrate of NMOS pipe, so V _SB1,2=V _S1,2, so V _SB1,2With V _C2Increase and reduce.According to the device theory, as the source class current potential V of the first earial drainage element MN1 or the second earial drainage element MN2 _SB1,2When non-vanishing, there is body bias effect in the MOS device.The threshold voltage formula of considering body bias effect is:

$V_{\mathrm{TH}}={\mathrm{<figure-callout\; id="0"\; label="V\; TH"\; filenames="HDA0000368661100000032.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{TH}}+\mathrm{\&gamma;}(\sqrt{2{\mathrm{\&Phi;}}_F-V_{\mathrm{SB}}|}-\sqrt{\left|2{\mathrm{\&Phi;}}_F\right|})$ (formula 3)

Φ wherein _F=(kT/q) ln (N _sub/ n _i) be positive number, V _TH0For not considering the NMOS pipe threshold voltage of body bias effect, N _subFor substrate mixes concentration, T is temperature value, k, q, n _iBe the preset parameter value.This formula shows, along with source class current potential V _SB1,2Reduce, threshold voltage also can reduce.

For leak-off pipe the first earial drainage element MN1 or the second earial drainage element MN2, controlled voltage V _C1Controlling and be operated in ，Qi saturation region, saturation region leakage current formula is:

$I_{\mathrm{<figure-callout\; id="1"\; label="D"\; filenames="HDA0000368661100000021.png,HDA0000368661100000022.png"\; state="\{\{state\}\}">\; <figure-callout\; id="2"\; label="D"\; filenames="HDA0000368661100000022.png,HDA0000368661100000032.png"\; state="\{\{state\}\}">D</figure-callout>\; </figure-callout>}\mathrm{1,2}}=\frac{1}{2}{\mathrm{\&mu;}}_n{C}_{\mathrm{ox}}\frac{W}{L}{({\mathrm{<figure-callout\; id="1"\; label="V\; GS"\; filenames="HDA0000368661100000021.png,HDA0000368661100000022.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{GS}}-{\mathrm{<figure-callout\; id="1"\; label="V\; TH"\; filenames="HDA0000368661100000021.png,HDA0000368661100000022.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{TH}})}^2=\frac{1}{2}{\mathrm{\&mu;}}_n{C}_{\mathrm{ox}}\frac{W}{L}{(V_{c1}-{\mathrm{<figure-callout\; id="1"\; label="V\; S"\; filenames="HDA0000368661100000021.png,HDA0000368661100000022.png"\; state="\{\{state\}\}">V</figure-callout>}}_S-{\mathrm{<figure-callout\; id="1"\; label="V\; TH"\; filenames="HDA0000368661100000021.png,HDA0000368661100000022.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{TH}})}^2$ (formula 4)

Can find out, control voltage V _C1When increasing, V _SB1,2Because of V _C2Increase and reduce, cause V _TH1,2Reduce, occur can be due to above-mentioned two effects the time and increase rapidly thereby flow through the electric current of the first earial drainage element MN1 and the second earial drainage element MN2, thus the first resistance R ₁With the second resistance R ₂Two ends pressure reduction also increases rapidly thereupon separately, and while making voltage that antenna induction arrives arrive the rectification module input end through pressure limiting resistance, its amplitude can obtain decay by a relatively large margin, namely the input voltage of rectification module (| V _In1-V _In2|) will be limited in the withstand voltage scope of rectification module input pipe, and rectifier output voltage V _recAlso will maintain in the required voltage range of chip normal operation.According to body bias effect principle above-mentioned, as source voltage V _SB>0 o'clock, the threshold voltage of NMOS pipe can be along with V _SBIncrease and increase, thereby the discharge capacity of the first earial drainage element MN1 and the second earial drainage element MN2 is limited.

When the voltage obtained at antenna induction was low, the restriction discharge capacity was extremely important concerning radio electronic label, because it has determined that directly whether label can work under this induced voltage, namely determined the operating distance of label.And the voltage obtained at antenna induction wishes that discharge capacity is very strong when very high, can be by the input voltage V of rectification module _In1, V _In2Be limited in the withstand voltage scope of rectification module input pipe, this needs very large leakage current to make the first resistance R ₁With the second resistance R ₂Enough large pressure drops of upper generation.According to metal-oxide-semiconductor saturation region leakage current (formula 4), the method for the increase metal-oxide-semiconductor electric current that can use has: 1) increase breadth length ratio; 2) improve V _GS3) reduce V _TH.If only using method 1), so not only need to take larger chip area, also can cause when antenna induction voltage is not high pressure, its larger electric current of will releasing, if do not limited, the situation of excessive earial drainage may appear, make voltage attenuation cause the output voltage of rectification module lower than V _{Rec_min}Situation, thereby chip can't be worked, reduced the chip operation distance.If only using method 2), in order to allow whole circuit can tackle high-pressure situations, it can run into the situation the same with method 1 in the face of low pressure the time, and it also can be subject to V simultaneously _C2Maximal value (V _rec) restriction.If only use method 3), also can run into and above-mentioned two kinds of situations that method is the same.And the present invention is in conjunction with above-mentioned three kinds of methods, make this circuit both complete the strong restrictions of the high pressure that antenna induction is obtained, significantly weakened again the limitation capability of the low pressure that antenna induction is obtained.

When not serving as a contrast the inclined to one side control element MN of pipe the first lining partially ₃With the inclined to one side control element MN of the second lining ₄The time, the substrate of leak-off pipe the first earial drainage element MN1 and the second earial drainage element MN2 and the equal ground connection of source class, do not exist lining partially, so the size of current of leak-off pipe only depends on control voltage V _C1.Be difficult to like this control voltage V by only regulating _C1Size just can make amplitude limiter circuit can effectively process the high pressure that antenna induction arrives, guarantee simultaneously that again the output voltage of rectification module under low pressure meets the minimum voltage requirement of whole circuit working.And lining is managed the inclined to one side control element MN of the first lining partially ₃With the inclined to one side control element MN of the second lining ₄Introducing, make the threshold voltage V of NMOS pipe _THUnder low pressure because body bias effect increases, thereby limit the discharge capacity of leak-off pipe the first earial drainage element MN1 and the second earial drainage element MN2, prevented under low pressure the excessively situation of earial drainage.In the situation that the voltage that antenna induction arrives is higher, lining is the inclined to one side control element MN of pipe the first lining partially ₃With the inclined to one side control element MN of the second lining ₄Can be owing to controlling voltage V _C2Increase, its conducting resistance is sharply reduced, the body bias effect of leak-off pipe sharply weakens, and can not affect equally the processing of this circuit to high-pressure situations.

Based on the foregoing circuit principle, can find out, the voltage obtained when antenna induction (| V _{ANT_A}-V _{ANT_B}|) be a bit larger tham V _{ANT_min}The time, the lining of leak-off pipe the first earial drainage element MN1 and the second earial drainage element MN2 is partially serious, and threshold voltage is high, and earial drainage is limited, thereby has prevented the generation of excessive earial drainage situation, i.e. antenna input voltage | V _{ANT_A}-V _{ANT_B}| be greater than V _{ANT_min}And the rectification input | V _In1-V _In2| but be less than V _{In_min}Situation.When the voltage of sensing when antenna increases gradually, the control voltage V of leak-off pipe the first earial drainage element MN1 and the second earial drainage element MN2 _C1Can increase, discharge capacity improves thereupon, and its body bias effect can be due to the inclined to one side control element MN of inclined to one side pipe the first lining of lining ₃With the inclined to one side control element MN of the second lining ₄Reducing of conducting resistance and weaken, its threshold voltage is descended, discharge capacity further strengthens, and too high antenna induction voltage is fallen to a greater degree on pressure limiting resistance, thereby realizes that the high pressure amplitude limit strengthens, the purpose that the low pressure amplitude limit weakens.

By negative-feedback technology in conjunction with body bias effect, can be so that the variation of amplitude limit ability adaptive antenna induced voltage amplitude, thus it is very weak to reach the low pressure amplitude limit, the effect that the high pressure amplitude limit is very strong finally makes the voltage of actual input rectifying module | V _In1-V _In2| be limited in the withstand voltage scope of rectification module input pipe.By amplitude limit, make the rectification module output voltage V that offers the rear class mu balanced circuit _recBe controlled in a rational scope, this voltage just can obtain almost constant DC voltage through mu balanced circuit, for each module work of chip.

As shown in Figure 3, the voltage magnitude that arrives of antenna induction (| V _{ANT_A}-V _{ANT_B}|) the input voltage amplitude of rectification module while changing to 20.5V from 2.5V | V _In1-V _In2| variation.The voltage magnitude obtained at antenna induction as we can see from the figure, (| V _{ANT_A}-V _{ANT_B}|) be 2.5V(low pressure) time, the input voltage amplitude of rectification module after amplitude limit | V _In1-V _In2| be 2.028V; The voltage magnitude obtained at antenna induction is the 20.5V(high pressure) time, the input voltage amplitude of rectification module is 2.885V after amplitude limit.When input voltage is increased to high voltage variable and turns to 18V from low pressure, the input voltage amplitude of rectification module | V _In1-V _In2| variation be only 0.857V, very small.

Figure 4 shows that the voltage magnitude that antenna induction obtains (| V _{ANT_A}-V _{ANT_B}|) output voltage V of corresponding rectification module while changing to 20.5V from 2.5V _recChange.Therefrom can see the nearly 20V of antenna end change in voltage, and rectifier output voltage V _recOnly changed less than 1V(1.85V～2.44V).Rectifier output voltage is further pressed by after the mu balanced circuit voltage stabilizing, obtaining galvanic current, gives each module for power supply of chip.

Fig. 5 is the voltage stabilizing output voltage V under the present embodiment _CCThe voltage magnitude arrived with antenna induction (| V _{ANT_A}-V _{ANT_B}|) simulation result that changes.Therefrom see, due to the excellent Limiting effect of rectification amplitude limiter circuit, although the voltage that antenna induction obtains changes to 20.5V from 2.5V, the voltage stabilizing output voltage V _CCVariation but less than 9mV(1.809V～1.818V).

From above-mentioned simulation result, can find out, the present invention has realized low pressure amplitude limit not substantially, the very strong function of high pressure amplitude limit simultaneously.For the ease of understanding, what adopt in the present embodiment is the most simply to obtain to control voltage V _C1, V _C2Method, although Limiting effect can meet the integrated circuit requirement, the excellent results of this invention does not embody fully in the examples of circuits of the present embodiment.

Claims (4)

1. the rectification amplitude limiter circuit of radio electronic label, is characterized by: the first resistance (R1) connection first input end (V _{ANT_A}) and the second resistance (R2) connection the second input end (V _{ANT_B}) after, all with the input end of the inclined to one side amplitude limit module of lining and rectification module, be connected, rectification module connects the inclined to one side amplitude limit module of described lining by two output voltage after the voltage monitoring control module, at lining, has the 4th resistance (R4) that the 3rd resistance (R3) that an end is connected with the first resistance (R1) and an end are connected with the second resistance (R2) in inclined to one side amplitude limit module, the other end of the 3rd resistance (R3) and the 4th resistance (R4) is connected respectively the first lining inclined to one side control element (MN3) and the rear ground connection of the second inclined to one side control element of lining (MN4) with the second earial drainage element (MN2) by the first earial drainage element (MN1), the control end of the first earial drainage element (MN1) and the second earial drainage element (MN2) all is connected a wherein road output voltage (V of described voltage monitoring control module _c1), the first inclined to one side control element of lining (MN3) and the second control end that serves as a contrast inclined to one side control element (MN4) all are connected another road output voltage (V of described voltage monitoring control module _c2).

2. the rectification amplitude limiter circuit of radio electronic label as claimed in claim 1, it is characterized by: described the first earial drainage element (MN1) and the second earial drainage element (MN2), and the first lining inclined to one side control element (MN3) and second serves as a contrast inclined to one side control element (MN4) and is nmos type transistor;

Corresponding the 3rd resistance (R3) and the 4th resistance (R4) of being connected of the drain electrode of the first earial drainage element (MN1) and the second earial drainage element (MN2), the corresponding drain electrode that is connected the first lining inclined to one side control element (MN3) and the second inclined to one side control element of lining (MN4) of the source electrode of the first earial drainage element (MN1) and the second earial drainage element (MN2);

The grid of the first earial drainage element (MN1) and the second earial drainage element (MN2) all is connected a wherein road output voltage (V of described voltage monitoring control module _C1);

The source grounding of the first lining inclined to one side control element (MN3) and the second inclined to one side control element of lining (MN4), grid all connects another road output voltage (V of voltage monitoring control module _C2).

3. the rectification amplitude limiter circuit of radio electronic label as claimed in claim 2, is characterized by: the equal ground connection of substrate of the first earial drainage element (MN1) of described nmos type transistor structure, the second earial drainage element (MN2), the first lining inclined to one side control element (MN3) and the second inclined to one side control element of lining (MN4).

4. as the rectification amplitude limiter circuit of the described radio electronic label of one of claims 1 to 3, it is characterized by: described rectification module is for intersecting the bridge rectifier module.

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