CN204425651U - TMR near field magnetic communication system - Google Patents
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- CN204425651U CN204425651U CN201420387199.3U CN201420387199U CN204425651U CN 204425651 U CN204425651 U CN 204425651U CN 201420387199 U CN201420387199 U CN 201420387199U CN 204425651 U CN204425651 U CN 204425651U
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Abstract
The utility model discloses a kind of TMR near field magnetic communication system, for detecting AC and the DC magnetic field that near field magnetic communication system produces, and AC and DC field signal is input to audio-frequency electric acoustic device as its input signal, audio-frequency electric acoustic device comprises the earphone of hearing aids, home entertainment system, has the public hearing circuit system (public hearing loop system) etc. of embedded hearing device.This system comprises: one or more bridge-type TMR transducer for AC and DC input; Comprise the analog circuit of filter, filter is used for AC and the DC Signal separator exported by TMR transducer; For the amplifier that the AC signal of telecommunication is amplified; Analog output is used for the AC signal of telecommunication to pass to audio-frequency electric acoustic device.TMR transducer can be linear or non-linearly TMR transducer, and wherein TMR transducer is designed in specific DC magnetic field, have best signal to noise ratio.
Description
Technical field
The present invention relates to a kind of device detecting near field magnetic communication system sound intermediate frequency signal, particularly relate to a kind of design of the magnetic resistance sensor for input, combined method, increase signal to noise ratio to reach, improve working direct current magnetic field range, reduce power consumption and realize the effect of many inductive axis.
Background technology
At present, more hearing aids utilizes line of induction ring type (T-coil) to adopt acoustic device and receives the AC magnetic signal come from the receiver of Telephone set.When using phone, the background signal that T-coil transducer wherein can help hearing aids user to eliminate people's ear can to hear, can avoid the reduction of sound quality simultaneously.And when primary sound formula hearing aids and telephone receiver use simultaneously, the reduction of sound quality occurs often.Best solution utilizes the DC magnetic field in telephone receiver to trigger the magnetic switch in hearing aids, closes the microphone of hearing aids, activates line of induction ring type (T-coil) and adopt acoustic device, instead of use hand switch mute microphone (MIC).
Except improving the sound quality of telephone receiving, hearing aids is just progressively applied in high-end consumer audio system and public broadcasting audio transmission system, T-coil transducer wherein, as the detector of near field magnetic communication system, has dual-use function in circuit system.As a rule, telephone signal picking up system, Public Address system, and the simulated audio signal in the near field magnetic communication system such as home audio is carried by magnetic field, and this magnetic field is very near transmission coil.This and conventional radio communication are different in several, and wherein maximum difference is: the magnetic field carrying audio signal near field magnetic communication system is not the electromagnetic wave of easily diffusion.So near field magnetic communication can only be carried out in a room or building, improves privacy, thus allow adjacent system only to respective local transmission information.
Traditional induction coil (T-coil) can only detect AC magnetic field, and induction coil has two kinds of forms, and one is passive type, forms by around the coil on magnetic core, and another kind is active, and it comprises a preamplifier.But, comparatively large, expensive for the inductance volume of picking up signal; In addition, induction coil self can not respond to the existence of D.C. magnetic field, must use additional circuit to detect the existence of the D.C. magnetic field coming from near-field communication equipment.These devices are all very large, occupy the space that hearing aids is larger, and these spaces can be used for other application of hearing aids originally, or can be used for the space increasing battery.Another shortcoming that traditional line of induction ring type adopts acoustic device is, traditional line of induction ring type transducer is vector, is not scalar type transducer, so it can only measure the changes of magnetic field along a direction.Only not necessarily just bad to single axial sensitivity, but due to the volume of coil large, coil is longer than the length along non-inductive axle in the length along inductive axis, causes the receiver being difficult to make traditional T-Coil and landline telephone to mate.
Summary of the invention
Therefore, be necessary the transducer that installation volume is less in hearing aids, with performance that is cost-saving, that reduce volume, increase greater functionality or battery and raising T-coil, and select preferably just with the T-coil that TMR transducer is made.In addition, little transducer can make circuit system (loop system) detect mutually perpendicular two magnetic-field components, and this scheme is just more and more general.And, because induction coil can not detect the D.C. magnetic field in base receiver, so need extra magnetic switch to trigger T-coil pattern.And TMR transducer can detect DC component, therefore it can have sensor/switch dual-use function.The present invention discloses the method by TMR transducer manufacture list sensitive axes or sensitive axle sensor system, magnetic switch, T-coil and circuit system (loop system) unit are integrated in a little encapsulation by this sensing system.
AC and the DC magnetic field that TMR near field magnetic communication system produces for detecting near field magnetic communication system, and magnetic signal is converted to the signal of telecommunication received by audio-frequency electric acoustic device (audio electroacoustic device), TMR near field magnetic communication system comprises
Detect the bridge-type magnetic resistance sensor TMR [A] in magnetic field;
The analogue signal circuit be connected with the output of bridge-type magnetic resistance sensor TMR [A], analogue signal circuit comprises filter and amplifier, AC with the DC signal of telecommunication that bridge-type magnetic resistance sensor TMR [A] exports is separated by filter, amplifier amplifies the AC signal of telecommunication, and the AC signal of telecommunication is passed to audio-frequency electric acoustic device by analog signal output;
The power circuit be connected with bridge-type magnetic resistance sensor TMR [A] and analogue signal circuit and provide the power input of supply of electric power for power circuit;
Bridge-type magnetic resistance sensor TMR [A] is the linear TMR magnetic resistance sensor of muting sensitivity, the linear TMR magnetic resistance sensor of high sensitivity or NONLINEAR TM R magnetic resistance sensor.
Preferably, this TMR near field magnetic communication system, also comprises:
The digital signal circuit be connected with bridge-type magnetic resistance sensor TMR [A], the DC component of the signal of telecommunication that digital signal circuit process magnetic resistance sensor TMR [A] exports;
Digital signal output end, the information of the DC component exported by bridge-type magnetic resistance sensor TMR [A] passes to audio-frequency electric acoustic device.
Preferably, power circuit comprises the flat duty ratio of height that occupancy controller controls bridge-type magnetic resistance sensor TMR [A]; Digital signal circuit comprises the comparator of the existence of the large DC signal of telecommunication detected in bridge-type magnetic resistance sensor TMR [A] output signal; When comparator detects the large DC signal of telecommunication in the output of TMR bridge-type magnetic resistance sensor [A], occupancy controller quits work, and its output is still DC offset voltage.
Preferably, power circuit comprises voltage multiplie, and when comparator detects the large DC signal of telecommunication in the output of bridge-type magnetic resistance sensor TMR [A], voltage multiplie is opened, and increases the bias voltage of bridge-type magnetic resistance sensor TMR [A].
Preferably, the bridge-type magnetic resistance sensor TMR [B] be connected with power circuit is comprised.
Preferably, TMR near field magnetic communication system, comprising:
The digital signal circuit process be connected with bridge-type magnetic resistance sensor TMR [B] comes from the DC signal of telecommunication of bridge-type magnetic resistance sensor TMR [B], digital signal circuit comprise one for detect bridge-type magnetic resistance sensor TMR [B] output in the comparator of larger DC component, when comparator in the output signal of bridge-type magnetic resistance sensor TMR [B] the DC signal of telecommunication detected time, comparator sends signal, and the bias voltage of bridge-type magnetic resistance sensor TMR [A] is opened;
Digital output end, the information of the DC component exported by bridge-type magnetic resistance sensor TMR [B] passes to audio-frequency electric acoustic device;
The resistance of resistance ratio bridge-type magnetic resistance sensor TMR [A] of bridge-type magnetic resistance sensor TMR [B] is large.
Preferably, power circuit comprises voltage multiplie, and when comparator detects the DC signal of telecommunication in the output of bridge-type magnetic resistance sensor TMR [B], voltage multiplie will be opened, to increase the bias voltage of bridge-type magnetic resistance sensor TMR [A].
Preferably, TMR near field magnetic communication system, comprise bridge-type magnetic resistance sensor TMR [C], bridge-type magnetic resistance sensor TMR [C] and magnetic resistance sensor TMR [B] detects two magnetic-field components along orthogonal directions respectively, magnetic resistance sensor TMR [C] is the linear TMR magnetic resistance sensor of high sensitivity, is used for detecting AC magnetic field.
Preferably, analogue signal circuit is connected to the output of bridge-type magnetic resistance sensor TMR [C], analogue signal circuit is separated and amplifies the AC signal of telecommunication that bridge-type magnetic resistance sensor TMR [C] exports, and the treated AC signal of telecommunication is passed to the analog signal output of TMR near field magnetic communication system.
Preferably, bridge-type magnetic resistance sensor TMR [A] and bridge-type magnetic resistance sensor TMR [B] is half-bridge, and full-bridge, recommends bridge, or their arbitrary combination; TMR near field magnetic communication system is packaged into thin membrane flip chip encapsulation, multi-chip package (COF), or chip on board encapsulation (COB); Bridge-type magnetic resistance sensor TMR [A] and bridge-type magnetic resistance sensor TMR [B] crystal grain upset technique makes.
Preferably, bridge-type magnetic resistance sensor is half-bridge, and full-bridge recommends bridge, or their arbitrary combination; TMR near field magnetic communication system is packaged into thin membrane flip chip encapsulation (single semiconductor package), multi-chip package (COF), or chip on board encapsulation (COB); Bridge-type magnetic resistance sensor crystal grain upset technique makes.
Preferably, bridge-type magnetic resistance sensor TMR [A] is the NONLINEAR TM R transducer adopting crystal grain upset technique to make, the bias magnetic field of each brachium pontis is greater than its saturation magnetic field, and bias magnetic field and saturation magnetic field sum equal the maximum DC magnetic field of the operation of bridge-type magnetic resistance sensor TMR [A].
Preferably, bridge-type magnetic resistance sensor TMR [A] is the NONLINEAR TM R transducer adopting crystal grain upset technique to make, the bias magnetic field of each brachium pontis is greater than its saturation magnetic field, and bias magnetic field and saturation magnetic field sum equal the maximum DC magnetic field of the operation of bridge-type magnetic resistance sensor TMR [A].
Preferably, TMR near field magnetic communication system, comprise a digital input end, for TMR near field magnetic communication system at hearing circuit pattern (Loop system mode), manual switchover between T-coil pattern and standby mode, wherein in standby mode, bridge-type magnetic resistance sensor TMR [A] does not work.
Preferably, TMR near field magnetic communication system, comprise a digital input end, for TMR near field magnetic communication system at hearing circuit pattern (Loop system mode), manual switchover between T-coil pattern and standby mode, wherein in standby mode, bridge-type magnetic resistance sensor TMR [A] does not work.
Preferably, TMR near field magnetic communication system, comprise bridge-type magnetic resistance sensor TMR [C], bridge-type magnetic resistance sensor TMR [C] and bridge-type magnetic resistance sensor TMR [A] detects the component in two orthogonal magnetic fields respectively, magnetic resistance sensor TMR [C] is the linear TMR transducer of high sensitivity, for detecting AC magnetic field, the output of bridge-type magnetic resistance sensor TMR [C] is buffered and is coupled with the audio frequency amplifier AC in analog circuit.
Preferably, TMR near field magnetic communication system, comprise digital signal circuit, digital signal circuit comprises comparator, comparator receive the DC signal of telecommunication from the output of bridge-type magnetic resistance sensor TMR [C] and bridge-type magnetic resistance sensor TMR [A], the output of comparator is connected to digital signal output end, and by digital signal output end by the DC component information that outputs signal of bridge-type magnetic resistance sensor TMR [A] be transferred to audio-frequency electric acoustic device.
Preferably, TMR near field magnetic communication system, comprises one or more extra bridge-type magnetic resistance sensor TMR [A1], TMR [A2] ..., TMR [Ai] (i is positive integer); All magnetic resistance sensor TMR [Ai] have different Hsat; All bridge-type magnetic resistance sensor TMR [Ai] and bridge-type magnetic resistance sensor TMR [A] detect the magnetic-field component of equidirectional; Bridge-type magnetic resistance sensor TMR [Ai] be the linear TMR magnetic resistance sensor of high sensitivity, muting sensitivity TMR magnetic resistance sensor or NONLINEAR TM R magnetic resistance sensor; The output of bridge-type magnetic resistance sensor TMR [A] and bridge-type magnetic resistance sensor TMR [Ai], through buffering, is coupled with the audio frequency amplifier AC in analog circuit.
Preferably, TMR near field magnetic communication system, the biased field of at least one bridge-type magnetic resistance sensor is greater than its saturation field, and the magnetic field range that it is being positioned at 10 ~ 100G is run, to obtain optimum signal-noise ratio.
Preferably, TMR near field magnetic communication system is packaged into thin membrane flip chip encapsulation (single semiconductor package), multi-chip package (COF), or chip on board encapsulation (COB); Bridge-type magnetic resistance sensor TMR [A] and bridge-type magnetic resistance sensor TMR [Ai] (i is positive integer) crystal grain upset technique makes.
Accompanying drawing explanation
In order to be illustrated more clearly in the technical scheme in embodiment of the present invention technology, be briefly described to the accompanying drawing used required in the description of embodiment technology below, apparently, accompanying drawing in the following describes is only some embodiments of the present invention, for those of ordinary skill in the art, under the prerequisite not paying creative work, other accompanying drawing can also be obtained according to these accompanying drawings.
Fig. 1 is MTJ profile, the display Rotating fields of MTJ and the circuit of measuring resistance;
Fig. 2 is the schematic diagram of the transformation curve that the magneto-resistor of conventional Spin Valve GMR, TMR changes with externally-applied magnetic field, and the direction of magnetization of its pinning layer points to the direction of-H;
Fig. 3 be the transformation curve that change with externally-applied magnetic field of the magneto-resistor of conventional Spin Valve GMR, TMR schematic diagram, the direction of the direction of magnetization sensing+H of its pinning layer;
Fig. 4 is the sketch of the method multiple TMR element being connected into an arm of electric bridge;
Fig. 5 is the full-bridge magnetic resistance sensor be made up of 4 sensing arm;
Fig. 6 is the transformation curve of linear TMR full-bridge magnetic resistance sensor;
Fig. 7 is the transformation curve of NONLINEAR TM R full-bridge magnetic resistance sensor;
Fig. 8 is the TMR near field magnetic communication system only employing a TMR magnetic resistance sensor;
Fig. 9 is for employing two TMR magnetic resistance sensors, and one of them is exclusively used in the TMR near field magnetic communication system that telephone audio field signal gathers;
Figure 10 is use three TMR magnetic resistance sensors, and one of them is exclusively used in the collection of telephone audio field signal, and at least one is exclusively used in the TMR near field magnetic communication system that hearing loop field signal gathers;
Figure 11 employs the TMR near field magnetic communication system that two TMR magnetic resistance sensors detect the component in two mutually perpendicular magnetic fields respectively, one of them TMR magnetic resistance sensor is exclusively used in the collection of telephone audio field signal, and at least one is exclusively used in the TMR near field magnetic communication system that hearing loop field signal gathers;
Figure 12 employs multiple TMR near field magnetic communication system with the TMR magnetic resistance sensor of different Hsat, and add the DC magnetic field threshold value scope that AC magnetic field can be detected, the AC field signal exceeding this DC magnetic field threshold value can be detected;
Figure 13 is optional multiple TMR magnetic resistance sensor, and it has widened the DC magnetic field threshold value scope that AC magnetic field can be detected, and AC magnetic signal can detect with high sensitivity TMR transducer.
Embodiment
Fig. 1 is the structure of tunneling junction magnetoresistive (MTJ) element and the schematic diagram of its resistance measurement.The Μ TJ Rotating fields 1 of a standard comprises pinning layer 3 magnetic coupling be made up of the pinned Ruthenium layer 4 of ferromagnetism and antiferromagnet and the magnetic nailed layer 2 formed, and by MgO or Al
2o
3the tunnel barrier layer 5 formed.Tunnel barrier layer 5 is deposited directly on the pinned Ruthenium layer 4 of ferromagnetism.Ferromagnetic layer 6 is deposited on above tunnel barrier layer 5.The direction of the magnetic moment direction 8 of magnetic nailed layer 2 and the magnetic moment direction 7 of sensitive layer as shown by arrows.The direction of magnetization 8 of pinning layer is stapled to a direction relatively regularly, can not change under not being very strong magnetic field intensity condition; Comparatively speaking, the magnetic moment direction 7 of sensitive layer can change with the change of external magnetic field.The magnetic moment direction 7 of free magnetic layer 6 represents with double-head arrow, and the direction 8 of nailed layer 4 represents exactly in order to show the difference of this rotary freedom with single arrow.The typical thickness of layer 3,4,5,6 is that 0.1nm is to tens nm.
Bottom directly contacts with 6 with MTJ upper strata 3 with 17 with top electrodes 16, is used for measuring magneto-resistor.Bottom and top electrodes 16 and 17 are made up of the metal of nonmagnetic conduction usually, must carry the electric current leading to ohmmeter 18.The whole Rotating fields of ohmmeter 18 couples of MTJ applies a known voltage (or electric current), and measures the electric current (or voltage) finally by MTJ.In general, tunnel barrier layer 5 provides most resistance, such as: barrier layer resistance is 10,000 ohms, and remainder resistance is 10 ohms.Bottom electrode 16 is positioned on insulating barrier 9, and insulating barrier 9 is formed on substrate 10, and the edge of insulating barrier 9 has stretched out the edge of bottom electrode 16.Substrate 10 is the most normal to be made up of silicon, but also can be glass, heat resistant glass, and GaAs, AlTiC or any other provide the goods and materials of suitable wafer Integrated Trait.Although magnetic resistance sensor does not always need integrated circuit, silicon is favored owing to being suitable for working integrated circuit.
Fig. 2 be GMR or Μ Τ J transducer the conventional output curve diagram of resistance ~ externally-applied magnetic field, the transducer with this curve is suitable for the measurement of linear magnetic field.Curve of output 30 is saturated when low resistance state 21 and high-impedance state 22, RL and RH represents the resistance value of low resistance state 21 and high-impedance state 22 respectively.Between two saturation conditions, curve of output is the linearity curve of externally-applied magnetic field H.The direction of externally-applied magnetic field H is parallel with the sensitive direction of transducer.When the direction of magnetization 8 of pinning layer and sensitive direction antiparallel, the direction of-H is pointed in pinned layer magnetization direction.When the direction of magnetization 7 of free magnetic layer and the direction of magnetization 8 of pinned magnetic layer parallel time, the measured resistance value of whole element is at low resistance state 21; When the direction of magnetization 8 antiparallel with pinned magnetic layer of the direction of magnetization 7 of free magnetic layer, the measured resistance value of whole element is at high-impedance state 22.Part below will describe, and direction that is relative at free layer 6 and nailed layer 4 is between 0-180 degree, and the resistance of MTJ element 1 obtains the value between high resistance and low resistance.
] curve of output 30 need not relative to H=0 point symmetry.Typical situation, there is a side-play amount H in saturation field 25 and 26
023, make low saturation field close to H=0 point.H
023 values are relevant with " orange effect " or " Neel coupling ", and its value is usually at 1-25 Oe, and relevant with the straight and even degree of ferromagnetic thin film in MR element, also depends on material and processing technology.H
023 can by reducing the magnetic bias of TMJ element and increase.
In order to the operation principle of TMR near field magnetic communication system is described, between saturation field 25 and 26, the curve of output of Fig. 2 can be expressed as approx:
(1)
H
sit is saturation field.The magnetic field value that when Hs is defined as low field quantitatively, the tangent line of curve of output is corresponding with the intersection point of the tangent line of curve of output time saturated, this value is ignoring H
0when acquired.
Fig. 3 be in Fig. 2 crystal grain (wafer cuts into the crystal grain of many, each crystal grain has a transducer) curve of output of the resistance ~ externally-applied magnetic field after 180 degree is have rotated relative to the axle of the plane orthogonal with transducer, through over-rotation, the direction of magnetization 8 of nailed layer points to+H direction now.This rotate as a result, under identical externally-applied magnetic field condition, the slope of R ~ H curve of output be do not rotate the negative value of slope of crystal grain.Only have and utilize this characteristic, just can build the magnetic resistance sensor of larger output, this method is for making the transducer in disclosed embodiment of this invention.Making linear TMR transducer by the method for rotational grain has been 201310718969.8,201310496945.2 at application number), 201120167350.9, and open in the Chinese patent application of 201110134982.X.
As shown in Figure 4, because their volumes are little, multiple MTJ element can be connected use, improves sensitivity, reduces 1/F noise, improves antistatic property.The MTJ element 40 of multiple electrical connection is between bottom electrode 41 and top electrodes 42, form sandwich structure, its electric connection mode makes electric current 43 flow longitudinally through MTJ40 and flows transversely through to be positioned at bottom and the top electrodes 42 that is alternately arranged of top conductive layer and bottom electrode 41.Bottom electrode 41 to be positioned on separator 9 and may to have extra substrate 10.When using bridge design, the reference arm of electric bridge is preferably identical with the size of the MTJ element 1 of sensing arm, the skew etching and cause can be eliminated like this, and utilize the design of element string, the MTJ element 40 of varying number can be used, to obtain the ratio of best sensing arm/reference arm resistance value in sensing arm and reference arm.
Electric bridge is used for resistance switching signal being converted to the voltage signal easily amplified.This can improve signal to noise ratio, eliminates common-mode noise, reduces thermal effect, etc.The MR element string of Fig. 4 can be used for being built into the Wheatstone bridge of Fig. 5 easily.Preferred is " full-bridge " 50; 4 arms of full-bridge 50 all have induction to externally-applied magnetic field H, are referred to as sensing arm.Sensing arm 52 and 52 ' transmission curve as shown in Figure 2, its slope is just; Sensing arm 54 and 54 ' transmission curve as shown in Figure 3, its slope is negative.In Fig. 5, the direction of arrow in sensing arm 52 and 54 represents that the symbol of their resistance value to the slope of the transformation curve of the intensity of externally-applied magnetic field is contrary.In addition, GHP: when by sensor production on substrate time, need following to be electrically connected pad: voltage bias pad (V
bias45), ground pad (GND, 46), the centre cap pad (V of two half-bridge circuits
1, 47, V
2, 48).The output voltage of full-bridge circuit 50 is shown in the curve 60 in Fig. 6 with the variation relation of externally-applied magnetic field.
In order to the R from the transformation curve 30 in Fig. 2 and Fig. 3
hand R
lthe curve of derivation graph 6
,need first to calculate when externally-applied magnetic field H is positive very large value, the difference V of voltage
1– V
2.Under this sensed conditions, sensing arm 52 and 52 ' resistance value are R
h; The resistance value of 54,54 ' is R
l;
Electric bridge from V
biasresistance value to GND is:
（2）
Since there is equal resistance value electric bridge both sides, the electric current of electric bridge both sides also should be identical, according to divided relation, can obtain:
(3)
The electromotive force of left side V1 point is:
(4)
The electromotive force of right side V2 point is:
（5）
The output of bridge-type magnetic resistance sensor is the difference of V1 and V2:
（6）
Vout in above formula is when additional forward magnetic field, and the output maximum of bridge-type magnetic resistance sensor, is designated as Vpeak 61 in Fig. 6.And as can be seen from the figure, tangent line 63 through initial point, and intersects at a H=Hsat with the line at+Vpeak value place.The susceptibility of bridge circuit output voltage is defined as: the slope of bridge circuit output voltage when H=0, as shown in the formula:
（7）
Fig. 6 is the curve of output V1-V2 ~ H of linear full-bridge sensors.The saturation field of Fig. 6 is defined as Hsat, needs the biased field adding each MTJ element, to revise the value of saturation field, as shown in the formula:
(8)
Note H that is that Hsat is more than or equal to single MTJ element or brachium pontis
s.Meanwhile, when the direction of the pinning layer of the MTJ element on the adjacent brachium pontis on electric bridge is contrary, the biased field H of single MTJ element group
owill be cancelled.
When using magnetic resistance sensor as audio frequency magnetic field signal picker, consider to have two important parameters to need to consider from the quality point of sound:
(1) saturation field (Hsat), and
(2) signal to noise ratio (SNR).
Here sensitivity definition is Vp/Hsat.Note the increase along with the field intensity needing the externally-applied magnetic field measured, Hsat also must correspondingly increase.This means when measuring stronger external magnetic field, the sensitivity of magnetic resistance sensor needs to decline.
The counter productive of sensitivity decrease is the Quality Down of the audio frequency magnetic field signal gathered.In the audiorange of 100Hz to 10KHz, Johnson noise model can describe the magnetic noise in TMR transducer well, Johnson noise is done integration in the bandwidth of T-coil, then gets root mean square:
（9）
F1 in formula is the low-limit frequency of passband, and F2 is highest frequency, k
bbe Boltzmann constant, T is temperature, and R is the resistance of the electric bridge of magnetic resistance sensor.The signal to noise ratio of the signal quality that representative measures can be expressed as relative to the amplitude Btest of the sound wave measured:
（10）
Along with Hsat increases, SNR reduces.
Design have high s/n ratio magnetic resistance sensor time, also have other factor that will consider.Vp is less than the bias voltage (Vbias) of magnetic resistance sensor, and relevant with the resistance change rate of magnetic resistance sensor with the structure of electric bridge.The resistance change rate of magnetic resistance sensor has the limitation of its reality, and Vp close to the bias voltage of magnetic resistance sensor, can only can not equal the bias voltage of magnetic resistance sensor.In fact, at its best, to recommend full-bridge, 0.45 Vbias <=Vp<=Vbias.The optimum sensitivity of recommending full-bridge linear magnetoresistance transducer is:
（11）
Vbias and Hsat examines quantitative limitation by DC magnetic field with the actual of power consumption.Therefore maximum sensitivity is subject to design restriction, even if improve linear transfer slope of a curve, can not significantly improve sensitivity.
The noise of certain magnetic resistance sensor also can affect SNR, so we can consider the noise reducing magnetic resistance sensor.From introducing above, Bns is determined by bandwidth, but the bandwidth determining audio frequency magnetic field signal by the sound of the mankind and music is unalterable.Although noise reduces with temperature, we cannot control temperature.Finally, noise reduces with the reduction of resistance.But the resistance reducing magnetic resistance sensor can increase power consumption, reduce the service time of battery, so resistance can not design too low.
The parameter affecting SNR can be summarised in formula below,
(12)
(13)
Suppose V
p~ 0.5 V
bias
(14) by arranging less R and Hsat, and larger Vbias, SNR can be optimized.But optimize and be subject to R, Hsat, and the restriction of the practicable value of Vbias.In base system, Hsat minimum value is approximately 35 Oe, so R and Vbias that only change.But less R and larger Vbias can cause larger power consumption, therefore linear magnetoresistance transducer as shown in Figure 6 SNR be subject to the constraint of the possible actual value of its parameter.
Notice that, in base application, TMR near field magnetic communication system only has when near telephone set, just can be used.Magnetic Sensor is through being commonly used for proximity switch to detect the existence of base.Magnetic switch can be triggered in DC magnetic field in telephone receiver, making magnetic switch be less than 10 Oe in magnetic field intensity and opens, so when not increasing power consumption, having two kinds of ways to improve SNR.
A kind of scheme, when needs use T-coil transducer, with the linear transducer of highly sensitive high resistance as magnetic switch, opens low-resistance linear TMR T-coil transducer.As Fig. 6, between interval 65A and 65B of two switching thresholds region, TMR T-coil transducer is idle.
Another kind of scheme, change the magnetic field ~ voltage transitions curve of TMR T-coil, make curve work as magnetic field intensity to become more flat (two between dotted line region) lower than 10Oe, and make curve work as magnetic field intensity when 10 Oe to 100 Oe, to become greatly steeper, (region two outside dotted line).This scheme is presented at Fig. 7.When magnetic resistance sensor gathers audio frequency magnetic field signal in this scope, its sensitivity is expressed as,
(15)
This is highly sensitive in the sensitivity of high sensitivity linear magnetoresistance transducer.The strong point of this magnetic resistance sensor is: in the magnetic field range needing collection signal, has high sensitivity, in order to reduce power consumption, can get higher resistance value.This magnetic resistance sensor can by making
H
o>H
s(16)
Realize.The method realizing Ho>Hs comprises Neel coupling, and substrate arranges biased permanent magnet, or exchange coupling.When using exchange coupling, be deposited on second inverse ferric magnetosphere on free layer for generation of bias magnetic field.
For object of the present invention, " high sensitivity linear transducer " is defined as the linear transducer of Hsat < 10 Oe, and " muting sensitivity linear transducer " or linear TMR transducer are defined as the linear transducer of Hsat > 20 Oe.Highly sensitive TMR transducer may be used for hearing circuit system, the collection of handset audio field signal, or magnetic switch.
Present invention uses three kinds of dissimilar TMR magnetic resistance sensors,
I. high sensitivity linear transducer
Ii. muting sensitivity linear transducer
Iii. NONLINEAR TM R magnetic resistance sensor, as high SNR, the telephone audio field signal collector of low power consumption
The magnetic resistance sensor of above-mentioned several types can form the combination of several difference in functionality, gathers or hearing circuit system for telephone audio field signal.
The TMR linear magnetoresistance transducer of i and ii can use various different method for designing, the correlation technique comprised with reference to bridge magnetic resistance sensor is shown in MDT2011.15 (CN102621504A), MDT2013.07.30 (201310719255.9), or MDT2013.01.14 (201310203311.3), the correlation technique that standard recommends bridge linear magnetoresistance transducer is shown in MDT2011.09(CN102331564A) or MDT2011.11 (CN102540112A), the method for designing that NONLINEAR TM R magnetic resistance sensor in iii must use pinning layer to reverse, be disclosed in MDT2013.09.15.X (201310718969.8), MDT2013.08.20.X, MDT2011.24 (CN202230192U), MDT2011.06 (CN102208530A), MDT2011.05 (CN102298125A) (CN102298125A), or MDT2011.11.30 (CN102565727A).
Hearing aids generally includes microphone, sound intensifier, and receiver.Microphones sound also converts thereof into the signal of telecommunication, and the signal of telecommunication coming from microphone amplifies by sound intensifier, and the signal of telecommunication be then exaggerated is passed to receiver, and the signal of telecommunication is converted back the voice signal importing people's ear into by receiver.When user uses phone, can mute microphone (MIC) be wanted, receive the AC magnetic field coming from telephone receiver and produce.Open TMR T-Coil and mute microphone (MIC) can manually complete, also can be realized by the magnetic switch detecting the DC magnetic field that telephone receiver produces.Below in conjunction with 4 embodiments, the present invention is described in detail.
embodiment 1
Fig. 8 is that the TMR near field magnetic communication system 11 that embodiment 1. can detect magnetic field comprises: bridge-type magnetic resistance sensor TMR [A] 24A detecting magnetic field; The analog circuit 37 be connected with the output of bridge-type magnetic resistance sensor TMR [A] 24A, analog circuit 37 comprises filter 18 and amplifier 12, filter 18 can by AC and the DC Signal separator of bridge-type magnetic resistance sensor TMR [A] 24A, and amplifier 12 amplifies AC signal; AC signal is passed to audio-frequency electric acoustic device by analog signal output 14; Power circuit 19 and being connected with bridge-type magnetic resistance sensor TMR [A] 24A and analog circuit 37; Power input 20 provides supply of electric power for power circuit 19.Wherein, bridge-type magnetic resistance sensor TMR [A] 24A is the linear TMR transducer of muting sensitivity, the linear TMR transducer of high sensitivity, or NONLINEAR TM R transducer.
TMR near field magnetic communication system 11 also comprises the digital signal circuit 27 be connected with bridge-type magnetic resistance sensor TMR [A] 24A in addition, and it can process the DC signal coming from bridge-type magnetic resistance sensor TMR [A] 24A and export.The signal of telecommunication processed through digital signal circuit 27 passes to audio-frequency electric acoustic device by digital output end 15.In addition, digital signal circuit 27 comprises comparator 29, and comparator 29 can detect the existence of the DC component in bridge-type magnetic resistance sensor TMR [A] 24A output signal.Occupancy controller 36 can control the high level duty ratio of the bias voltage of magneto-resistor bridge type magnetic sensor TMR [A] 24A, when comparator 29 detects DC magnetic field in the output of bridge-type magnetic resistance sensor TMR [A] 24A, occupancy controller 36 will be closed.In addition, power circuit 19 comprises voltage multiplie 28, and it can increase the bias voltage of bridge-type magnetic resistance sensor TMR [A] 24A; When comparator 29 detects larger DC magnetic field in the output of bridge-type magnetic resistance sensor TMR [A] 24A, voltage multiplie 28 will be opened.
In a first embodiment, bridge-type magnetic resistance sensor TMR [A] 24A is half-bridge, full-bridge, recommends bridge or their arbitrary combination.TMR T-Coil near field magnetic communication system can be packaged into chip package on flexible board (COF), multi-chip package (single semiconductor package) or chip on board encapsulation (COB).TMR magnetic resistance sensor adopts crystal grain upset (flip die) technology or single bare chip (single die) fabrication techniques.
embodiment 2
Fig. 9 is second embodiment, and TMR near field magnetic communication system 11 comprises: for measuring bridge-type magnetic resistance sensor TMR [A] 24A in magnetic field; The analogue signal circuit 37 be connected with the output of bridge-type magnetic resistance sensor TMR [A] 24A, analogue signal circuit 37 comprises filter 18 and amplifier 12, AC with the DC signal of telecommunication that bridge-type magnetic resistance sensor TMR [A] 24A exports can be separated by filter 18, and amplifier 12 amplifies the AC signal of telecommunication; The AC signal of telecommunication is passed to audio-frequency electric acoustic device by analog signal output 14; Power circuit 19 is connected with bridge-type magnetic resistance sensor TMR [A] 24A and analogue signal circuit 37; Power input 20 provides supply of electric power for the power circuit 19 of TMR near field magnetic communication system 11.Wherein, bridge-type magnetic resistance sensor TMR [A] 24A is the linear TMR transducer of muting sensitivity, or NONLINEAR TM R transducer.
TMR near field magnetic communication system 11 also comprises bridge-type magnetic resistance sensor TMR [B] 24B, and bridge-type magnetic resistance sensor TMR [B] 24B is the linear TMR magneto-resistor of a high sensitivity or muting sensitivity, can detect the DC magnetic field in Telephone set receiver.Bridge-type magnetic resistance sensor TMR [A] 24A and bridge-type magnetic resistance sensor TMR [B] 24B detects the magnetic-field component of equidirectional.
TMR near field magnetic communication system 11 also comprises in addition: the digital signal circuit 27 be connected with bridge-type magnetic resistance sensor TMR [B] 24B, and it can process the DC signal of telecommunication coming from bridge-type magnetic resistance sensor TMR [B] 24B; Digital output end 15, for passing to audio-frequency electric acoustic device by the DC information of bridge-type magnetic resistance sensor TMR [A] 24A.Wherein, digital signal circuit 27 comprises comparator 29, and comparator 29 can detect the existence in DC magnetic field from bridge-type magnetic resistance sensor TMR [B] 24B outputs signal.Occupancy controller 36 can control the high level duty ratio of the bias voltage of bridge-type magnetic resistance sensor TMR [B] 24B.Power circuit 19 comprises voltage multiplie 28, and it can increase the bias voltage of bridge-type magnetic resistance sensor TMR [A] 24A; When comparator 29 detects existing of larger DC component in the output of bridge-type magnetic resistance sensor TMR [B] 24B, voltage multiplie 28 will open the bias voltage increasing bridge-type magnetic resistance sensor TMR [A] 24A.
TMR near field magnetic communication system 11 can also comprise a digital signal input end, and for TMR near field magnetic communication system 11 at hearing circuit pattern, manual switchover between T-coil pattern and standby mode, wherein in standby mode, TMR T-coil does not work.
embodiment 3
Figure 10 is embodiment 3.TMR near field magnetic communication system sound 11 comprises: for detecting bridge-type magnetic resistance sensor TMR [A] 24A in magnetic field; The analogue signal circuit 37 be connected with the output of bridge-type magnetic resistance sensor TMR [A] 24A, analogue signal circuit 37 comprises filter 18 and amplifier 12, AC with the DC signal of telecommunication of the output of bridge-type magnetic resistance sensor TMR [A] 24A can be separated by filter 18, and amplifier 12 amplifies the AC signal of telecommunication; The AC signal of telecommunication is passed to audio-frequency electric acoustic device by analog signal output 14; Power circuit 19 is connected with bridge-type magnetic resistance sensor TMR [A] 24A and analogue signal circuit 37; Power input 20 provides supply of electric power for power circuit 19.Wherein, bridge-type magnetic resistance sensor TMR [A] 24A is the linear TMR transducer of muting sensitivity, or NONLINEAR TM R transducer.
TMR near field magnetic communication system 11 also comprises bridge-type magnetic resistance sensor TMR [B] 24B, bridge-type magnetic resistance sensor TMR [B] 24B is the linear TMR magnetic resistance sensor of a high sensitivity or muting sensitivity, can detect the DC magnetic field in Telephone set receiver.Bridge-type magnetic resistance sensor TMR [A] 24A and bridge-type magnetic resistance sensor TMR [B] 24B detects the magnetic-field component of equidirectional.The power supply of bridge-type magnetic resistance sensor TMR [B] 24B can by the power supply signal after occupancy controller copped wave, to reduce energy ezpenditure.
TMR near field magnetic communication system 11 comprises in addition: the digital signal circuit 27 be connected with bridge-type magnetic resistance sensor TMR [B] 24B, and it can process the DC signal coming from bridge-type magnetic resistance sensor; Numeral exports 15 by the direct current signal information transmission of bridge-type magnetic resistance sensor TMR [A] 24A to audio-frequency electric acoustic device.Wherein, digital signal circuit 27 comprises comparator 29, and comparator 29 can detect the existence of the DC component in bridge-type magnetic resistance sensor TMR [B] 24B output signal.Occupancy controller 36 in a power 19 can control the high level duty ratio of the bias voltage of bridge-type magnetic resistance sensor TMR [B] 24B.In addition, power circuit 19 comprises voltage multiplie 28, it can increase the bias voltage of bridge-type magnetic resistance sensor TMR [A] 24A, and when comparator 29 detects larger DC component in the output of bridge-type magnetic resistance sensor TMR [B] 24B, voltage multiplie 28 will be opened.
TMR near field magnetic communication system 11 also comprises bridge-type magnetic resistance sensor TMR [C] 24C, bridge-type magnetic resistance sensor TMR [C] 24C and bridge-type magnetic resistance sensor TMR [B] 24B detects mutually perpendicular two magnetic-field components, bridge-type magnetic resistance sensor TMR [C] 24C is the TMR magnetic resistance sensor of highly sensitive dimension, and it is used for detecting AC magnetic field.
Analog signal 37 also comprises: the buffer 44C being connected to bridge-type magnetic resistance sensor TMR [C] 24C output; The AC signal of telecommunication of bridge-type magnetic resistance sensor TMR [C] 24C is separated by filter 18; Amplifier 12 amplifies this AC signal of telecommunication, and the signal be exaggerated is passed to the output 14 of the analog signal of TMR near field magnetic communication system 11.In addition, buffer 44A is connected to the output of bridge-type magnetic resistance sensor TMR [A] 24A, isolates preferably to make it with bridge-type magnetic resistance sensor TMR [C] 24C signal.
Power circuit 19 comprises voltage multiplie 28, to increase the bias voltage of bridge-type magnetic resistance sensor TMR [A] 24A and TMR [C] 24C; Only have when comparator 29 detects the DC component of suitable intensity in the output of bridge-type magnetic resistance sensor TMR [B] 24B, voltage multiplie 28 just can be opened.
Bridge-type magnetic resistance sensor TMR [A] 24A, bridge-type magnetic resistance sensor TMR [B] 24B and bridge-type magnetic resistance sensor TMR [C] 24C are half-bridges, and full-bridge, recommends bridge, or their arbitrary combination.
TMR near field magnetic communication system 11 may comprise another digital signal input end, and for TMR near field magnetic communication system 11 at hearing circuit pattern, manual switchover between T-coil pattern and standby mode, wherein in standby mode, TMR T-coil does not work.
TMR T-Coil near field magnetic communication system can be packaged into chip package on flexible board (COF), multi-chip package (single semiconductor package) or chip on board encapsulation (COB).
embodiment 4
Figure 11 is AC and the DC magnetic field that embodiment 4, TMR near field magnetic communication system 11 is used for detecting near field magnetic communication system, AC and DC magnetic field is converted to the signal of telecommunication that can be accepted by audio-frequency electric acoustic device.TMR near field magnetic communication system 11 comprises a pair TMR transducer placed in 90 degree, can detect two orthogonal magnetic-field components respectively.This is bridge-type magnetic resistance sensor TMR [A] 24A to TMR transducer, bridge-type magnetic resistance sensor TMR [C] 24C.The output of bridge-type magnetic resistance sensor TMR [A] 24A and bridge-type magnetic resistance sensor TMR [C] 24C is all connected to respective buffer, by filter, itself AC with DC signal of telecommunication is separated, and the AC signal of telecommunication of two transducers is exaggerated device 12 amplifies.Analog signal output 14 is used for the AC signal of telecommunication to pass to audio-frequency electric acoustic device.Power circuit 19 is connected with bridge-type magnetic resistance sensor TMR [A] 24A with TMR [C] 24C and analog circuit 37, and power input 20 provides supply of electric power for the power circuit 19 of TMR near field magnetic communication system 11.Bridge-type magnetic resistance sensor TMR [A] 24A and TMR [C] 24C is the linear TMR transducer of muting sensitivity, the linear TMR transducer of high sensitivity, or NONLINEAR TM R transducer.
TMR near field magnetic communication system 11 comprises digital signal circuit 27, and digital signal circuit 27 comprises comparator 29, and the direct-flow output signal of bridge-type magnetic resistance sensor TMR [A] 24A and TMR [C] 24C is transferred to comparator 29.The output of comparator 29 is connected to digital output end 15, and the DC signal message of bridge-type magnetic resistance sensor TMR [A] 24A and TMR [C] 24C is passed to audio-frequency electric acoustic device by digital output end 15.
Power circuit 19 can comprise voltage multiplie 28, and it can increase the bias voltage of bridge-type magnetic resistance sensor TMR [A] 24A and TMR [C] 24C.When comparator 29 detect in the output of bridge-type magnetic resistance sensor TMR [A] 24A and TMR [C] 24C have enough DC components time, voltage multiplie 28 will be opened.Power circuit 19 can comprise occupancy controller 36, when not having enough DC components in the output at bridge-type magnetic resistance sensor TMR [A] 24A and TMR [C] 24C, it controls the high level duty ratio of the bias voltage of bridge-type magnetic resistance sensor TMR [A] 24A and TMR [C] 24C.
Bridge-type magnetic resistance sensor TMR [A] 24A, TMR [B] 42B and TMR [C] 24C is half-bridge, and full-bridge, recommends bridge, or their arbitrary combination.
TMR near field magnetic communication system 11 may comprise another digital signal input end, and for TMR near field magnetic communication system 11 at hearing circuit pattern, manual switchover between T-coil pattern and standby mode, wherein in standby mode, TMR T-coil does not work.
TMR T-Coil near field magnetic communication system can be packaged into chip package on flexible board (COF), multi-chip package (single semiconductor package) or chip on board encapsulation (COB).
embodiment 5
Figure 12 is embodiment 5.In order to expand DC magnetic field threshold value scope in AC magnetic field detection, TMR near field magnetic communication system 11 also comprises the extra magnetic resistance sensor TMR [A1] that several detect equidirectional magnetic-field component, TMR [A2], TMR [Ai] (i is positive integer), and these extra magnetic resistance sensor TMR [A1], TMR [A2],, the sensitive direction of TMR [Ai] (i is positive integer) is identical with magnetic resistance sensor TMR [A].There is provided electric power by power circuit 19, the output of each transducer is connected with the input cushioning the analogue signal circuit 37 inputted.These magnetic resistance sensors have different Hsat, and Hsat distribution as shown in figure 13.This design makes in very wide DC magnetic field range, and AC magnetic field can obtain level and smooth measurement.Power circuit 19 comprises the voltage multiplie 28 that can improve magnetic resistance sensor sensitivity and the occupancy controller 36 reducing power consumption.The output of each magnetic resistance sensor is through buffer, output to high pass filter 18, every road of filter 18 exports and is connected with amplifier 12 electricity, the AC signal of telecommunication coming from magnetic resistance sensor amplifies by amplifier 12, and through analog output 14, the AC signal of telecommunication is after treatment passed to audio-frequency electric acoustic device.
These are only embodiments of the invention, be not limited to the present invention, for a person skilled in the art, the present invention can have various modifications and variations.Within the spirit and principles in the present invention all, any amendment done, equivalent replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (20)
1.TMR near field magnetic communication system, for detecting AC and the DC magnetic field that near field magnetic communication system produces, and magnetic signal is converted to the signal of telecommunication received by audio-frequency electric acoustic device, it is characterized in that, described TMR near field magnetic communication system comprises
Detect the bridge-type magnetic resistance sensor TMR [A] in magnetic field;
The analogue signal circuit be connected with the output of bridge-type magnetic resistance sensor TMR [A], described analogue signal circuit comprises filter and amplifier, AC with the DC signal of telecommunication that described bridge-type magnetic resistance sensor TMR [A] exports is separated by described filter, described amplifier amplifies the described AC signal of telecommunication, and the described AC signal of telecommunication is passed to described audio-frequency electric acoustic device by analog signal output;
The power circuit be connected with described bridge-type magnetic resistance sensor TMR [A] and described analogue signal circuit and provide the power input of supply of electric power for described power circuit;
Described bridge-type magnetic resistance sensor TMR [A] is the linear TMR magnetic resistance sensor of muting sensitivity, the linear TMR magnetic resistance sensor of high sensitivity or NONLINEAR TM R magnetic resistance sensor.
2. TMR near field magnetic communication system according to claim 1, is characterized in that, comprising:
The digital signal circuit be connected with described bridge-type magnetic resistance sensor TMR [A], the DC component of the signal of telecommunication that magnetic resistance sensor TMR [A] exports described in described digital signal circuit process;
Digital signal output end, the information of the DC component described bridge-type magnetic resistance sensor TMR [A] exported passes to described audio-frequency electric acoustic device.
3. TMR near field magnetic communication system according to claim 2, is characterized in that, described power circuit comprises the flat duty ratio of height that occupancy controller controls described bridge-type magnetic resistance sensor TMR [A]; Described digital signal circuit comprises the comparator of the existence of the large described DC signal of telecommunication detected in described bridge-type magnetic resistance sensor TMR [A] output signal; When described comparator detects the large described DC signal of telecommunication in the output of bridge-type magnetic resistance sensor TMR [A], described occupancy controller quits work, and its output is still DC offset voltage.
4. TMR near field magnetic communication system according to claim 3, it is characterized in that, described power circuit comprises voltage multiplie, when described comparator detects the large described DC signal of telecommunication in the output of bridge-type magnetic resistance sensor TMR [A], described voltage multiplie is opened, and increases the bias voltage of described bridge-type magnetic resistance sensor TMR [A].
5. TMR near field magnetic communication system according to claim 1, is characterized in that, comprises the bridge-type magnetic resistance sensor TMR [B] be connected with described power circuit.
6. TMR near field magnetic communication system according to claim 5, comprising:
The digital signal circuit process be connected with described bridge-type magnetic resistance sensor TMR [B] comes from the DC signal of telecommunication of described bridge-type magnetic resistance sensor TMR [B], described digital signal circuit comprise one for detect described bridge-type magnetic resistance sensor TMR [B] output in the comparator of larger DC component, when described comparator in the output signal of described bridge-type magnetic resistance sensor TMR [B] the described DC signal of telecommunication detected time, described comparator sends signal, and the bias voltage of described bridge-type magnetic resistance sensor TMR [A] is opened;
Digital output end, the information of the DC component described bridge-type magnetic resistance sensor TMR [B] exported passes to described audio-frequency electric acoustic device;
Described in the resistance ratio of bridge-type magnetic resistance sensor TMR [B], the resistance of bridge-type magnetic resistance sensor TMR [A] is large.
7. TMR near field magnetic communication system according to claim 6, it is characterized in that, described power circuit comprises voltage multiplie, when described comparator detects the DC signal of telecommunication in the output of described bridge-type magnetic resistance sensor TMR [B], described voltage multiplie will be opened, to increase the bias voltage of bridge-type magnetic resistance sensor TMR [A].
8. the TMR near field magnetic communication system according to any one of claim 5-7, it is characterized in that, comprise bridge-type magnetic resistance sensor TMR [C], described bridge-type magnetic resistance sensor TMR [C] and described magnetic resistance sensor TMR [B] detect two magnetic-field components along orthogonal directions respectively, described magnetic resistance sensor TMR [C] is the linear TMR magnetic resistance sensor of high sensitivity, is used for detecting described AC magnetic field.
9. TMR near field magnetic communication system according to claim 8, it is characterized in that, described analogue signal circuit is connected to the output of described bridge-type magnetic resistance sensor TMR [C], described analogue signal circuit is separated and amplifies the AC signal of telecommunication that described bridge-type magnetic resistance sensor TMR [C] exports, and the treated described AC signal of telecommunication is passed to the analog signal output of described TMR near field magnetic communication system.
10. TMR near field magnetic communication system according to any one of claim 1 or 5; it is characterized in that, described bridge-type magnetic resistance sensor TMR [A] and described bridge-type magnetic resistance sensor TMR [B] are half-bridges, full-bridge; recommend bridge, or their arbitrary combination; Described TMR near field magnetic communication system is packaged into thin membrane flip chip encapsulation, multi-chip package, or chip on board encapsulation; Bridge-type magnetic resistance sensor TMR [A] and described bridge-type magnetic resistance sensor TMR [B] make by crystal grain upset technique.
11. described TMR near field magnetic communication systems according to Claim 8, it is characterized in that, described bridge-type magnetic resistance sensor is half-bridge, and full-bridge, recommends bridge, or their arbitrary combination; Described TMR near field magnetic communication system is packaged into thin membrane flip chip encapsulation, multi-chip package, or chip on board encapsulation; Bridge-type magnetic resistance sensor crystal grain upset technique makes.
12. TMR near field magnetic communication systems according to claim 10, it is characterized in that, described bridge-type magnetic resistance sensor TMR [A] is the NONLINEAR TM R transducer adopting crystal grain upset technique to make, the bias magnetic field of each brachium pontis is greater than its saturation magnetic field, and described bias magnetic field and described saturation magnetic field sum equal the maximum DC magnetic field of the operation of described bridge-type magnetic resistance sensor TMR [A].
13. TMR near field magnetic communication systems according to claim 11, it is characterized in that, described bridge-type magnetic resistance sensor TMR [A] is the NONLINEAR TM R transducer adopting crystal grain upset technique to make, the bias magnetic field of each brachium pontis is greater than its saturation magnetic field, and described bias magnetic field and described saturation magnetic field sum equal the maximum DC magnetic field of the operation of described bridge-type magnetic resistance sensor TMR [A].
14. TMR near field magnetic communications according to claim 1 or 5, it is characterized in that, comprise a digital input end, for TMR near field magnetic communication system at hearing circuit pattern, manual switchover between T-coil pattern and standby mode, wherein in standby mode, bridge-type magnetic resistance sensor TMR [A] does not work.
15. TMR near field magnetic communication systems according to claim 8, it is characterized in that, comprise a digital input end, for TMR near field magnetic communication system at hearing circuit pattern, manual switchover between T-coil pattern and standby mode, wherein in standby mode, bridge-type magnetic resistance sensor TMR [A] does not work.
16. TMR near field magnetic communication systems according to claim 1, it is characterized in that, comprise bridge-type magnetic resistance sensor TMR [C], described bridge-type magnetic resistance sensor TMR [C] and described bridge-type magnetic resistance sensor TMR [A] detect the component in two orthogonal magnetic fields respectively, described magnetic resistance sensor TMR [C] is the linear TMR transducer of high sensitivity, for detecting AC magnetic field, the output of described bridge-type magnetic resistance sensor TMR [C] is buffered and is coupled with the described audio frequency amplifier AC in described analog circuit.
17. TMR near field magnetic communication systems according to claim 16, it is characterized in that, comprise digital signal circuit, described digital signal circuit comprises comparator, described comparator receives the DC signal of telecommunication from the output of described bridge-type magnetic resistance sensor TMR [C] and described bridge-type magnetic resistance sensor TMR [A], the output of described comparator is connected to described digital signal output end, and by digital signal output end, the DC component information that described bridge-type magnetic resistance sensor TMR [A] outputs signal is transferred to described audio-frequency electric acoustic device.
18. TMR near field magnetic communication systems according to claim 1, is characterized in that, comprise one or more extra bridge-type magnetic resistance sensor TMR [A1], TMR [A2] ..., TMR [Ai], described i are positive integer; All described magnetic resistance sensor TMR [Ai] have different Hsat; All described bridge-type magnetic resistance sensor TMR [Ai] and described bridge-type magnetic resistance sensor TMR [A] detect the magnetic-field component of equidirectional; Described bridge-type magnetic resistance sensor TMR [Ai] is the linear TMR magnetic resistance sensor of high sensitivity, muting sensitivity TMR magnetic resistance sensor or NONLINEAR TM R magnetic resistance sensor; The output of described bridge-type magnetic resistance sensor TMR [A] and described bridge-type magnetic resistance sensor TMR [Ai], through buffering, is coupled with the described audio frequency amplifier AC in described analog circuit.
19. TMR near field magnetic communication systems according to claim 16 or 18, it is characterized in that, the biased field of at least one bridge-type magnetic resistance sensor is greater than its saturation field, and the magnetic field range that it is being positioned at 10 ~ 100G is run, to obtain optimum signal-noise ratio.
20. according to claim 16 or 18 TMR near field magnetic communication system, it is characterized in that, described TMR near field magnetic communication system is packaged into thin membrane flip chip encapsulation, multi-chip package, or chip on board encapsulation; Described bridge-type magnetic resistance sensor TMR [A] and described bridge-type magnetic resistance sensor TMR [Ai] make by crystal grain upset technique.
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| CN104301851A (en) * | 2014-07-14 | 2015-01-21 | 江苏多维科技有限公司 | TMR near-field magnetic communication system |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104301851A (en) * | 2014-07-14 | 2015-01-21 | 江苏多维科技有限公司 | TMR near-field magnetic communication system |
| WO2016008370A1 (en) * | 2014-07-14 | 2016-01-21 | 江苏多维科技有限公司 | Tmr near-field magnetic communication system |
| CN104301851B (en) * | 2014-07-14 | 2018-01-26 | 江苏多维科技有限公司 | TMR near fields magnetic communication system |
| US10277992B2 (en) | 2014-07-14 | 2019-04-30 | MultiDimension Technology Co., Ltd. | TMR near-field magnetic communication system |
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