(19)
(11)EP 3 101 654 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
09.09.2020 Bulletin 2020/37

(21)Application number: 15290151.8

(22)Date of filing:  05.06.2015
(51)International Patent Classification (IPC): 
G11C 11/16(2006.01)
G01R 33/00(2006.01)
H03F 15/00(2006.01)
G01R 33/09(2006.01)

(54)

MAGNETIC DEVICE CONFIGURED TO PERFORM AN ANALOG ADDER CIRCUIT FUNCTION AND METHOD FOR OPERATING SUCH MAGNETIC DEVICE

MAGNETISCHE VORRICHTUNG, DIE ZUR AUSFÜHRUNG EINER ANALOGEN ADDIERSCHALTUNGSFUNKTION AUSGESTALTET IST UND VERFAHREN ZUM BETRIEB SOLCH EINER MAGNETISCHEN VORRICHTUNG

DISPOSITIF MAGNÉTIQUE CONFIGURÉ POUR RÉALISER UNE FONCTION DE CIRCUIT ADDITIONNEUR ANALOGIQUE ET PROCÉDÉ DE FONCTIONNEMENT D'UN TEL DISPOSITIF MAGNÉTIQUE


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(43)Date of publication of application:
07.12.2016 Bulletin 2016/49

(73)Proprietor: Crocus Technology
38025 Grenoble Cedex (FR)

(72)Inventor:
  • Stainer, Quentin
    38330 Montbonnot-ST-Martin (FR)

(74)Representative: P&TS SA (AG, Ltd.) 
Avenue J.-J. Rousseau 4 P.O. Box 2848
2001 Neuchâtel
2001 Neuchâtel (CH)


(56)References cited: : 
EP-A1- 2 712 078
US-A1- 2006 092 689
WO-A1-2013/123363
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    Field



    [0001] The present invention concerns a magnetic device configured to perform an analog adder circuit function. The present invention concerns a method for operating the magnetic device.

    Description of related art



    [0002] Addition of analog signals is a fundamental operation in signal theory and has many applications, for instance, in audio with mixing consoles. Addition of analog signals is typically performed by using a summing amplifier, or adder, circuit based on operational amplifiers.

    [0003] However, operational amplifiers are typically limited in bandwidth. Moreover, operational amplifiers feature output noise even in the absence of input and can be easily destroyed by voltage overshoots in the inputs, etc. As a result, for some applications, specific operational amplifier designs are required, usually leading to a significant cost increase.

    [0004] EP2712078 discloses a magnetic logic unit (MLU) cell comprising: a first magnetic tunnel junction and a second magnetic tunnel junction, each magnetic tunnel junction comprising a first magnetic layer having a first magnetization, a second magnetic layer having a second magnetization, and a tunnel barrier layer between the first and second layer; and a field line for passing a field current such as to generate an external magnetic field adapted to switch the first magnetization; the first magnetic layer being arranged such that the magnetic tunnel junction magnetization varies linearly with the generated external magnetic field.

    [0005] WO2O13123363 discloses an apparatus that includes a circuit and a field line. The circuit includes a magnetic tunnel junction including a storage layer and a sense layer. The field line is configured to generate a magnetic field based on an input signal, where the magnetic tunnel junction is configured such that a magnetization direction of the sense layer and a resistance of the magnetic tunnel junction vary based on the magnetic field. The circuit is configured to amplify the input signal to generate an output signal that varies in response to the resistance of the magnetic tunnel junction.

    [0006] US20O6092689 discloses a reference current source for a magnetic memory device is preferably configured with magnetic tunnel junction cells and includes more than four reference magnetic memory cells to improve reliability of the magnetic memory device and to reduce sensitivity at a device level to individual cell failures. The reference current source includes a large number of magnetic memory cells coupled in an array, and a current source provides a reference current dependent on the array resistance. In another embodiment a large number of magnetic memory cells are coupled to current sources that are summed and scaled to produce a reference current source. A current comparator senses the unknown state of a magnetic memory cell. This document proposes a digital n-inputs adder including magnetic units in parallel, each magnetic unit including n magnetic tunnel junctions in series, n input lines wherein each magnetic tunnel junction has its resistance varying based on a corresponding input on a corresponding input line.

    Summary of invention



    [0007] An n-inputs analog adder of the invention is defined by claim 1 and a method for operating said n-inputs analog adder is defined by claim 7.

    [0008] Using such magnetic units as claimed allows the magnetic device to have any number of inputs, such that building a 3, 4 or n-inputs adder is straightforward. Moreover, the magnetic device requires no in-situ programming. The magnetic device is directly functional after its fabrication including an initial annealing setting of the storage magnetization pinning direction. In the magnetic device disclosed herein, the output is not electrically connected to the inputs. An advantage of this configuration is the absence of leakages as well as risks of destruction of the output section due to voltage overshoots in the inputs. Process induced variability can be compensated by using several magnetic units in serial configuration.

    Brief Description of the Drawings



    [0009] The invention will be better understood and other advantages of the invention will become apparent with the aid of the description of an embodiment given by way of example and illustrated by the figures, in which:

    Fig. 1 shows a magnetic unit configured to perform an analog adder circuit function with two inputs,

    Fig. 2 represents a variation of a resistance of the magnetic unit with the amplitude of an input current;

    Fig. 3 shows a magnetic unit configured to perform an analog adder circuit function with four inputs,

    Fig. 4 illustrates a magnetic device comprising a plurality of magnetic units configured to perform an analog adder circuit function with two inputs, according to an embodiment; and

    Fig. 5 illustrates a magnetic device comprising a plurality of magnetic units configured to perform an analog adder circuit function with two inputs, according to an example not covered by the claims.


    Detailed Description of possible embodiments



    [0010] Fig. 1 shows a magnetic unit 1 configured to perform an analog adder circuit function. The magnetic unit 1 comprises a first magnetic tunnel junction 2 and a second magnetic tunnel junction 2'. Each magnetic tunnel junction 2, 2' includes a storage layer 23 having a storage magnetization 230, a sense layer 21 having a sense magnetization 210 that can be varied with respect to the storage magnetization 230, and a tunnel barrier layer 22 between the sense and storage layers 21, 23. The first and second magnetic tunnel junctions 2, 2' are electrically connected in series via a current line 3.

    [0011] The magnetic unit 1 further comprises a first input line 4 located below the first magnetic tunnel junction 2. The first input line 4 is configured such as to generate a first magnetic field 42 when a first input signal 41 is provided to the first input line 4. The first magnetic field 42 is adapted for varying a direction of the sense magnetization 210 and a first junction resistance R1 of the first magnetic tunnel junction 2.

    [0012] The magnetic unit 1 further comprises a second input line 4' located below (or at any other appropriate locations) the second magnetic tunnel junction 2'. The second input line 4' is configured such as to generate a second magnetic field 42' when a second input signal 41' is provided to the second input line 4'. The second magnetic field 42' is adapted for varying a direction of the sense magnetization 210 and a second junction resistance R2 of the second magnetic tunnel junction 2'.

    [0013] Each of the sense layer 21 and the storage layer 23 includes, or is formed of, a magnetic material and, in particular, a magnetic material of the ferromagnetic type. A ferromagnetic material can be characterized by a substantially planar magnetization with a particular coercivity, which is indicative of a magnitude of a magnetic field to reverse the magnetization after it is driven to saturation in one direction. In general, the sense layer 21 and the storage layer 23 can include the same ferromagnetic material or different ferromagnetic materials. The sense layer 21 can include a soft ferromagnetic material, namely one having a relatively low coercivity, while the storage layer 23 can include a hard ferromagnetic material, namely one having a relatively high coercivity. In such manner, a magnetization of the sense layer 21 can be readily varied under low-intensity magnetic fields generated in response to the input signals 41, 41' while the storage magnetization 230 remains stable. Suitable ferromagnetic materials include transition metals, rare earth elements, and their alloys, either with or without main group elements. For example, suitable ferromagnetic materials include iron ("Fe"), cobalt ("Co"), nickel ("Ni"), and their alloys, such as permalloy (or Ni 8oFe 2o); alloys based on Ni, Fe, and boron ("B"); CoFe; and alloys based on Co, Fe, and B. In some instances, alloys based on Ni and Fe (and optionally B) can have a smaller coercivity than alloys based on Co and Fe (and optionally B). A thickness of each of the sense layer 21 and the storage layer 23 can be in the nm range, such as from about 1 nm to about 20 nm. Other implementations of the sense layer 21 and the storage layer 23 are contemplated. For example, either, or both, of the sense layer 21 and the storage layer 23 can include multiple sub-layers in a fashion similar to that of the so-called synthetic antiferromagnetic layer.

    [0014] The tunnel barrier layer 22 includes, or is formed of, an insulating material. Suitable insulating materials include oxides, such as aluminum oxide (e.g., Al2O3) and magnesium oxide (e.g., MgO). A thickness of the tunnel barrier layer 22 can be in the nm range, such as from about 1 nm to about 10 nm.

    [0015] In the variant illustrated in Fig. 1, each magnetic tunnel junction 2, 2' also includes a pinning layer 24, which is disposed adjacent to the storage layer 23 and, through exchange bias, stabilizes the storage magnetization 230 along a particular direction when a temperature within, or in the vicinity of, the pinning layer 24 is at a low temperature threshold TL. The pinning layer 24 unpins, or decouples, the storage magnetization 230 when the temperature is at a high temperature threshold TH, thereby allowing the storage magnetization 230 to be switched to another direction.

    [0016] In one example, such a pinning layer is omitted adjacent to the sense layer 21, and, as a result, the sense layer 21 has a sense magnetization 210 that is unpinned and is readily varied, with the substantial absence of exchange bias.

    [0017] The pinning layer 24 includes, or is formed of, a magnetic material and, in particular, a magnetic material of the antiferromagnetic type. Suitable antiferromagnetic materials include transition metals and their alloys. For example, suitable antiferromagnetic materials include alloys based on manganese (Mn), such as alloys based on iridium (Ir) and Mn (e.g., IrMn); alloys based on Fe and Mn (e.g., FeMn); alloys based on platinum (Pt) and Mn (e.g., PtMn); and alloys based on Ni and Mn (e.g., NiMn). In some instances, the blocking temperature T Bs of alloys based on Ir and Mn (or based on Fe and Mn) can be in the range of about 120°C to about 220°C or about 150°C to about 200°C, such as about 200°C, and can be smaller than the blocking temperature T Bs of alloys based on Pt and Mn (or based on Ni and Mn), which can be in the range of about 300°C to about 350°C.

    [0018] In one i example, the input lines 4, 4' may be positioned underneath the current line 3 connecting the two magnetic tunnel junctions 2, 2' of the magnetic unit 1 (for example, at about 50 nm).

    [0019] The magnetic tunnel junctions 2, 2' are further configured to add said first and second input signal 41, 41' to generate an output signal Vout that varies in response to the first and second junction resistances R1, R2 of the first and second magnetic tunnel junctions 2, 2', respectively. The output signal Vout may flow through current line 3, and may be measured across output terminals 34 and 35.

    [0020] In one example, the first input signal 41 includes an input current flowing in the first input line 4 such that a first magnetic field 42 generated by the first input signal 41, is coupled to the first magnetic tunnel junction 2. The second input signal 41' also includes a current current flowing in the second input line 4' such that a second magnetic field 42' generated by the second input signal 41', is coupled to the second magnetic tunnel junction 2'.

    [0021] Other configurations of the magnetic unit 1 are also contemplated. For example, the magnetic unit 1 can comprises more than two magnetic tunnel junctions. In 3, the magnetic unit 1 further comprises a third magnetic tunnel junction 2" and a fourth magnetic tunnel junction 2'''. A third input line 4" is configured to generate a third magnetic field 42" adapted for varying a direction of the sense magnetization 210 and a third junction resistance R3 of the third magnetic tunnel junction 2", based on a third input signal 41". A fourth input line 4''' configured to generate a fourth magnetic field 42''' adapted for varying a direction of the sense magnetization 210 and a fourth junction resistance R4 of the fourth magnetic tunnel junction 2''', based on a fourth input signal 41'''. The magnetic unit 1 is configured to add said first, second, third and fourth input signals 41, 41', 41 ", 41 ''' to generate an output signal Vout that varies in response to the first, second, third and fourth junction resistances R1, R2, R3, R4 of the first, second, third and fourth magnetic tunnel junctions 2, 2', 2", 2''', respectively.

    [0022] The magnetic unit 1 can also comprise n magnetic tunnel junctions and n input lines. Each of the n magnetic units 1 is configured to add n inputs to generate an output signal Vout that varies in response to n resistances of the n magnetic tunnel junctions.

    [0023] When the input signal is zero (e.g., zero input current), the sense magnetization 210 and the storage magnetization 230 can be naturally substantially anti-aligned (e.g., substantially antiparallel), resulting in a series resistance Rout (corresponding to the sum of the junction resistances) per magnetic unit that is high. When the input signal is sufficiently large (above a threshold input value), the sense magnetization 210 becomes substantially aligned (e.g., substantially parallel) with the storage magnetization 230, resulting in a series resistance Rout per magnetic unit that is low. In such a configuration, the value of the series resistance Rout decreases with the input signal increasing above the threshold input value. The value of the series resistance Rout, and in particular the ratio between the series resistance, will depend on forming the sense layer 21 and/or the storage layer 23 from different choices of materials, material concentrations, and/or material thicknesses.

    [0024] The series resistance Rout varies linearly with the varying input signal 41, 41', 41", 41 '''.

    [0025] Possibly, each magnetic tunnel junction 2, 2', 2", 2''' comprises an easy axis aligned along the direction of the input line 4, 4', 4", 4'''. The easy axis can be achieved from shape or magnetocrystalline anisotropy of the magnetic tunnel junction 2, 2', 2", 2'''. The storage magnetization 230 is then aligned and pinned in a direction that is substantially perpendicular to the easy axis (thus substantially orthogonal to the direction of the input line). Aligning the storage magnetization 230 can be achieved by performing an annealing step under a strong and constant magnetic field. The easy axis direction and alignment of the storage magnetization 230 can be performed during the fabrication and deposition of the magnetic tunnel junctions 2, 2', 2", 2'''.

    [0026] In this configuration, when the input signal 41, 41', 41", 41''' is zero the sense magnetization 210 is oriented in an initial direction substantially perpendicular to the storage magnetization 230 and parallel to the input line 4, 4', 4", 4'''. The sense magnetization 210 is gradually aligned substantially parallel or antiparallel to the storage magnetization 230 by increasing an amplitude of the input signal 41, 41', 41", 41''' is passed in the input line 4, 4', 4", 4''' (the input signal does not need to be above a threshold input value to align the sense magnetization 210).

    [0027] In Figs. 3, the input signal includes an input current 41, 41', 41", 41 ''' flowing in the input line 4, 4', 4", 4''' and generating a magnetic field 42, 42', 42", 42''' oriented substantially parallel to the input line 4, 4', 4", 4'" and perpendicular with the initial direction of the sense magnetization 210. The graph of Fig. 2 reports a linear variation of the resistance R1, R2, R3, R4 of the first, second, third or fourth magnetic tunnel junctions 2, 2', 2", 2''', (corresponding to the variation in the sense magnetization 210) with the amplitude of the corresponding input current 41, 41', 41", 41 ''' (represented by I in Fig. 2) until a saturation input current Isat where the sense magnetization 210 is substantially parallel to the storage magnetization 230.

    [0028] The saturation input current Isat is individual to each input 41, 41', 41", 41'''. This implies that the current range available for an input is completely independent on the signal injected in the other inputs. In contrast, an adder based on operational amplifiers feature a common saturation behavior on the output.

    [0029] A magnetic device 100 configured to perform an analog adder circuit function is formed by assembling a plurality of magnetic units 1. In one embodiment illustrated in Fig. 4, a two-input magnetic device 100 comprises four magnetic units 1 electrically connected in series along a first input line 4 and a second input line 4'. The adjacent magnetic units 1 are electrically connected via the current line 3 having a curved and/or serpentine shape.

    [0030] The magnetic device 100 may include any number of magnetic units 1. For example, the magnetic device 100 may comprise n magnetic units 1 where n can be equal to any number, for example up to 100 or 500.

    [0031] The magnetic units 1 included in the magnetic device 100 may be arranged in an array with Np parallel rows of magnetic units 1, each row having Ns magnetic units 1 in series. This array may be compact. For example, 50,000 magnetic units 1may fit in a footprint with an area in the range from about 0.1 to about 0.5 square millimetres.

    [0032] In a variant, each of the magnetic units 1 of the magnetic device 100 can comprise more than two magnetic tunnel junctions and two input lines. For example, a four-input magnetic device 100 can be obtained by electrically connecting in series magnetic units 1 comprising four magnetic tunnel junctions 2, 2', 2", 2''' and four input lines 4, 4', 4", 4''', such as the one shown in Fig. 3.

    [0033] In another example not covered by the claims and illustrated in Fig. 5, a two-input magnetic device 100 comprises four magnetic units 1 electrically connected in parallel along a first input line 4 and a second input line 4'. In particular, the magnetic device 100 comprises two branches each including two magnetic units 1 electrically connected in series. The two-input magnetic device 100 of Fig. 5 can also comprise n branches each including two magnetic units 1 electrically connected in series. Each magnetic unit 1 can further comprise four magnetic tunnel junctions 2, 2', 2", 2''' and four input lines 4, 4', 4", 4''', such as to obtain a four-input magnetic device 100.

    [0034] The magnetic device 100 may include bias circuitry (not shown) that supplies the input signals 41, 41', 41", 41'''. The bias circuitry may include circuitry that supplies a sense current 31 (see Fig. 1) to facilitate generation of the output signal Vout. The magnetic device 100 may be solely driven externally through its input 41, 41', 41", 41''' and output terminals 34, 35.

    [0035] The output signal Vout of the magnetic device 100 is measured across output terminals 34 and 35 and results from an average of the output signal Vout of the plurality of magnetic units 1 (the output signal Vout varies in response to the n junction resistances R1, R2, R3, R4 of the n magnetic tunnel junctions 2, 2', 2", 2''' for each magnetic unit 1.

    [0036] In the case the series resistance Rout varies linearly with the varying input signal 41, 41', 41", 41''' the junction resistance R1, R2, R3, R4, and thus the output signal Vout, are directly proportional to the sum of the input currents 41, 41', 41", 41'".

    [0037] In one embodiment, a method for operating the magnetic device 100 comprises:

    providing an input 41, 41', 41", 41''' to each of the input lines 4, 4', 4", 4''' such as to generate a magnetic field 42, 42', 42", 42''' adapted for varying a direction of the sense magnetization 210 and a junction resistance R1, R2, R3, R4 of the corresponding magnetic tunnel junction 2, 2', 2", 2'''; and

    measuring an output signal Vout of the magnetic device 100.



    [0038] In an embodiment, the storage magnetization 230 is pinned in a direction being substantially perpendicular to the direction of the input lines 4, 4', 4", 4'''. The direction of the sense magnetization 210 is varied from an initial direction substantially perpendicular to the direction of the storage magnetization 230 to a direction substantially parallel or antiparallel to the direction of the storage magnetization 230.

    Reference Numbers and Symbols



    [0039] 
    1
    magnetic unit
    100
    magnetic device
    2
    magnetic tunnel junction
    21
    sense layer
    210
    sense magnetization
    22
    tunnel barrier layer
    23
    storage layer
    230
    storage magnetization
    24
    pinning layer
    3
    current line
    31
    sense current
    34
    output terminal
    35
    output terminal
    4
    first input line
    4'
    second input line
    4"
    third input line
    4'''
    fourth input line
    41
    first input
    41'
    second input
    41"
    third input
    41'''
    fourth input
    42
    first magnetic field
    42'
    second magnetic field
    42"
    third magnetic field
    42'''
    fourth magnetic field
    R1
    first junction resistance
    R2
    second junction resistance
    R3
    third junction resistance
    R2
    fourth junction resistance
    Rout
    series resistance
    TH
    high temperature threshold
    TL
    low temperature threshold
    Vout
    output signal



    Claims

    1. An n-inputs analog adder (100) configured to perform an analog adder circuit function, the magnetic device (100) comprising a plurality of magnetic units, each of the plurality of magnetic units including:

    n magnetic tunnel junctions (2, 2', 2', 2''',...), each magnetic tunnel junction (2, 2', 2', 2''',...) comprising a storage magnetic layer (23) having a storage magnetization (230), a sense magnetic layer (21) having a sense magnetization (210) that can be varied with respect to the storage magnetization (230), and a tunnel barrier layer (22) between the sense magnetic layer and the storage magnetic layer (21, 23);

    a current line (3) electrically connecting in series said n magnetic tunnel junctions (2, 2', 2', 2''',...);

    n input lines (4, 4', 4', 4''',...), each input line being configured to generate a magnetic field (42, 42', 42', 42''',...) adapted for varying a direction of the sense magnetization (210) and a junction resistance (R1, R2, R3, R4, ...) of a corresponding one of said n magnetic tunnel junctions (2, 2', 2', 2''',...), based on a corresponding input (41, 41', 41', 41''',...), wherein the junction resistance (R1, R2, R3, R4, ...) of said corresponding one of said n magnetic tunnel junctions (2, 2', 2', 2''',...) varies linearly based on said corresponding input signal(41, 41', 41', 41''',...); and

    wherein each of the plurality of magnetic units is configured to add said n inputs (41, 41') to generate an output signal (Vout) that varies in response to the n junction resistances (R1, R2, R3, R4, ...) of said n magnetic tunnel junctions (2, 2', 2', 2''',...), and, each of the n input lines (4, 4', 4', 4''',...) are independent of one another such that the the n input lines (4, 4', 4', 4''',...) can conduct n independent input signals so that the output signal (Vout) can vary as a function of said n independent input signals; and

    wherein said plurality of magnetic units comprises N magnetic units electrically connected in series along said n input lines (4, 4', 4', 4''',...) and wherein said N magnetic units are arranged such that for each input line of the n input lines (4, 4', 4', 4''',...) the corresponding magnetic tunnel junctions of all the magnetic units are aligned in a direction parallel to the one of said input line.


     
    2. The n-inputs analog adder according to claim 1,
    wherein n = 2, such that the n-inputs analog adder (100) has two inputs (41, 41').
     
    3. The n-inputs analog adder according to claim 1,
    wherein n = 4, such that the n-inputs analog adder (100) has four inputs (41, 41', 41", 41''').
     
    4. The n-inputs analog adder according to any one of claims 1 to 3,
    wherein the current line is a serpentine.
     
    5. The n-inputs analog adder according to any one of claims 1 to 4,
    wherein, for each of the magnetic tunnel junctions, the storage magnetization (230) is pinned in a direction being substantially perpendicular to the direction of the input lines (4, 4', 4", 4''', ...).
     
    6. The n-inputs analog adder according to claim 5,
    wherein each magnetic tunnel junction (2, 2', 2", 2''', ...) comprises an anisotropy with an easy axis aligned substantially along a direction of the input lines (4, 4', 4", 4''', ...).
     
    7. Method for operating the n-inputs analog adder (100) according to one of the claims 1 to 6, comprising:

    providing an input (41, 41', 41', 41''', ...) to each of the input lines (4, 4') such as to generate a magnetic field (42, 42', 42', 42''', ...) for varying a direction of the sense magnetization (210) and the junction resistance (R1, R2, R3, R4, ...) of the corresponding magnetic tunnel junctions (2, 2', 2", 2''', ...); and

    measuring the signal (Vout) of the n-inputs analog adder (100)


     
    8. The method according to claim 7,
    wherein, for each of the magnetic tunnel junctions, the storage magnetization (230) is pinned in a direction being substantially perpendicular to the direction of the input lines (4, 4', 4", 4''', ...); and the direction of the sense magnetization (210) is gradually varied from an initial direction substantially perpendicular to the direction of the storage magnetization (230) to a direction substantially parallel or antiparallel to the direction of the storage magnetization (230) by increasing the amplitude of the corresponding input signal.
     


    Ansprüche

    1. Analoger Addierer mit n Eingängen (100), der zum Ausführen einer analogen Addiererschaltungsfunktion ausgelegt ist, wobei die magnetische Vorrichtung (100) eine Mehrzahl von magnetischen Einheiten umfasst, wobei jede der magnetischen Einheiten umfasst:

    n magnetische Tunnelübergänge (2, 2', 2', 2"', ...), wobei jeder magnetische Tunnelübergang (2, 2', 2', 2"', ...) eine magnetische Speicherschicht (23) mit einer Speichermagnetisierung (230), eine magnetische Leseschicht (21) mit einer Lesemagnetisierung (210), die in Bezug auf die Speichermagnetisierung (230) geändert werden kann, und eine Tunnelsperrschicht (22) zwischen der magnetische Speicherschicht und der magnetische Leseschicht (21, 23) umfasst;

    eine Stromleitung (3), welche die n magnetischen Tunnelübergänge (2, 2', 2', 2"', ...) in Reihe elektrisch verbindet;

    n Eingangsleitungen (4, 4', 4', 4"', ...), wobei jede Eingangsleitung so ausgelegt ist, dass sie ein Magnetfeld (42, 42', 42', 42''', ...) erzeugt, das zum Ändern einer Richtung der Lesemagnetisierung (210) und eines Übergangswiderstands (R1, R2, R3, R4, ...) eines entsprechenden der n magnetischen Tunnelübergänge (2, 2', 2', 2"', ...) basierend auf einem entsprechenden Eingang (41, 41', 41', 41''', ...) ausgelegt ist, wobei der Übergangswiderstand (R1, R2, R3, R4, ...) des entsprechenden der n magnetischen Tunnelübergänge (2, 2', 2', 2''', ...) basierend auf dem entsprechenden Eingangssignal (41, 41', 41', 41"', ...) linear variiert; und

    wobei jede der Mehrzahl von magnetischen Einheiten so ausgelegt ist, dass sie die n Eingänge (41, 41') addiert, um ein Ausgangssignal (Vout) zu erzeugen, das in Reaktion auf die n Übergangswiderstände (R1, R2, R3, R4, ...) der n magnetischen Tunnelübergänge (2, 2', 2', 2"', ...) variiert, und alle der n Eingangsleitungen (4, 4', 4', 4"', ...) voneinander unabhängig sind, derart dass die n Eingangsleitungen (4, 4', 4', 4"', ...) n unabhängige Eingangssignale führen können, so dass das Ausgangssignal (Vout) als eine Funktion der n unabhängigen Eingangssignale variieren kann; und

    wobei die Mehrzahl von magnetischen Einheiten N magnetische Einheiten umfasst, die entlang der n Eingangsleitungen (4, 4', 4', 4"', ...) in Reihe elektrisch verbunden sind, und wobei die N magnetischen Einheiten derart angeordnet sind, dass für jede Eingangsleitung der n Eingangsleitungen (4, 4', 4', 4"', ...) die entsprechenden magnetischen Tunnelübergänge aller magnetischen Einheiten in einer Richtung parallel zu der einen der Eingangsleitung ausgerichtet sind.


     
    2. Analoger Addierer mit n Eingängen nach Anspruch 1,
    wobei n = 2, derart dass der analoge Addierer mit n Eingängen (100) zwei Eingänge (41, 41') aufweist.
     
    3. Analoger Addierer mit n Eingängen nach Anspruch 1,
    wobei n = 4, derart dass der analoge Addierer mit n Eingängen (100) vier Eingänge (41, 41', 41", 41"') aufweist.
     
    4. Analoger Addierer mit n Eingängen nach einem der Ansprüche 1 bis 3, wobei die Stromleitung eine Serpentine ist.
     
    5. Analoger Addierer mit n Eingängen nach einem der Ansprüche 1 bis 4,
    wobei für jeden der magnetischen Tunnelübergänge die Speichermagnetisierung (230) in einer Richtung verstiftet ist, die im Wesentlichen senkrecht zur Richtung der Eingangsleitungen (4, 4', 4", 4''',...) ist.
     
    6. Analoger Addierer mit n Eingängen nach Anspruch 5,
    wobei jeder magnetische Tunnelübergang (2, 2', 2", 2''', ...) eine Anisotropie mit einer leichten Achse umfasst, die im Wesentlichen entlang einer Richtung der Eingangsleitungen (4, 4', 4", 4"', ...) ausgerichtet ist
     
    7. Betriebsverfahren für den analogen Addierer mit n Eingängen (100) nach einem der Ansprüche 1 bis 6, umfassend:

    Bereitstellen eines Eingangs (41, 41', 41', 41"', ...) für jede der Eingangsleitungen (4, 4'), um ein Magnetfeld (42, 42', 42', 42"', ...) zum Ändern einer Richtung der Lesemagnetisierung (210) und des Übergangswiderstands (R1, R2, R3, R4, ...) der entsprechenden magnetischen Tunnelübergänge (2, 2', 2", 2"', ...) zu erzeugen; und

    Messen des Ausgangssignals (Vout) des analogen Addierers mit n Eingängen (100).


     
    8. Verfahren nach Anspruch 7,
    wobei für jeden der magnetischen Tunnelübergänge die Speichermagnetisierung (230) in einer Richtung verstiftet wird, die im Wesentlichen senkrecht zur Richtung der Eingangsleitungen (4, 4', 4", 4''', ...) ist; und
    die Richtung der Lesemagnetisierung (210) von einer Anfangsrichtung, die im Wesentlichen senkrecht zur Richtung der Speichermagnetisierung (230) ist, durch Erhöhen der Amplitude der entsprechenden Eingangssignals schrittweise in eine Richtung geändert wird, die im Wesentlichen parallel oder antiparallel zur Richtung der Speichermagnetisierung (230) ist.
     


    Revendications

    1. Additionneur analogique à n entrées (100) configuré pour effectuer une fonction de circuit additionneur analogique, le dispositif magnétique (100) comprenant une pluralité d'unités magnétiques, chacune de la pluralité d'unités magnétiques comportant :

    n jonctions tunnels magnétiques (2, 2', 2', 2''', ...), chaque jonction tunnel magnétique (2, 2', 2', 2''', ...) comprenant une couche magnétique de stockage (23) ayant une aimantation de stockage (230), une couche magnétique de détection (21) ayant une aimantation de détection (210) que l'on peut faire varier par rapport à l'aimantation de stockage (230), et une couche barrière tunnel (22) entre la couche magnétique de détection et la couche magnétique de stockage (21, 23) ;

    une ligne de courant (3) branchant électriquement en série lesdites n jonctions tunnels magnétiques (2, 2', 2', 2''', ... )) ;

    n lignes d'entrée (4, 4', 4', 4''', ...), chaque ligne d'entrée étant configurée pour générer un champ magnétique (42, 42', 42', 42''', ...) adapté pour faire varier une direction de l'aimantation de détection (210) et une résistance de jonction (R1, R2, R3, R4, ...) d'une jonction correspondante parmi lesdites n jonctions tunnels magnétiques (2, 2', 2', 2''', ...) sur la base d'une entrée correspondante (41, 41', 41', 41''', ...), la résistance de jonction (R1, R2, R3, R4, ...) de ladite jonction correspondante parmi lesdites n jonctions tunnels magnétiques (2, 2', 2', 2''', ...) variant linéairement sur la base dudit signal d'entrée correspondant (41, 41', 41', 41''', ...) ; et

    dans lequel chacune de la pluralité d'unités magnétiques est configurée pour ajouter lesdites n entrées (41, 41') pour générer un signal de sortie (Vout) qui varie en réponse aux n résistances de jonction (R1, R2, R3, R4, ...) desdites n jonctions tunnels magnétiques (2, 2', 2', 2''', ...), et chacune des n lignes d'entrée (4, 4', 4', 4''', ...) est indépendante des autres de telle sorte que les n lignes d'entrée (4, 4', 4', 4''', ...) peuvent conduire n signaux d'entrée indépendants de telle sorte que le signal de sortie (Vout) peut varier en fonction desdits n signaux d'entrée indépendants ; et

    dans lequel ladite pluralité d'unités magnétiques comprend N unités magnétiques branchées électriquement en série le long desdites n lignes d'entrée (4, 4', 4', 4''', ...) et dans lequel lesdites N unités magnétiques sont agencées de telle sorte que, pour chaque ligne d'entrée donnée parmi les n lignes d'entrée (4, 4', 4', 4''', ...), les jonctions tunnels magnétiques correspondantes de toutes les unités magnétiques sont alignées dans une direction parallèle à ladite ligne d'entrée donnée.


     
    2. Additionneur analogique à n entrées selon la revendication 1, dans lequel n = 2, de telle sorte que l'additionneur analogique à n entrées (100) a deux entrées (41, 41').
     
    3. Additionneur analogique à n entrées selon la revendication 1, dans lequel n = 4, de telle sorte que l'additionneur analogique à n entrées (100) a quatre entrées (41, 41', 41", 41''').
     
    4. Additionneur analogique à n entrées selon l'une quelconque des revendications 1 à 3, dans lequel la ligne de courant est un serpentin.
     
    5. Additionneur analogique à n entrées selon l'une quelconque des revendications 1 à 4 dans lequel, pour chacune des jonctions tunnels magnétiques, l'aimantation de stockage (230) est bloquée dans une direction sensiblement perpendiculaire à la direction des lignes d'entrée (4, 4', 4", 4''', ...).
     
    6. Additionneur analogique à n entrées selon la revendication 5, dans lequel chaque jonction tunnel magnétique (2, 2', 2", 2''', ...) présente une anisotropie avec un axe facile aligné sensiblement le long d'une direction des lignes d'entrée (4, 4', 4", 4''', ...).
     
    7. Procédé de fonctionnement de l'additionneur analogique à n entrées (100) selon une des revendications 1 à 6, comprenant :

    la fourniture d'une entrée (41, 41', 41', 41''', ...) à chacune des lignes d'entrée (4, 4') de manière à générer un champ magnétique (42, 42', 42', 42''', ...) pour faire varier une direction de l'aimantation de détection (210) et la résistance de jonction (R1, R2, R3, R4, ...) des jonctions tunnels magnétiques correspondantes (2, 2', 2", 2''', ...) ; et

    la mesure du signal de sortie (Vout) de l'additionneur analogique à n entrées (100).


     
    8. Procédé selon la revendication 7 dans lequel, pour chacune des jonctions tunnels magnétiques, l'aimantation de stockage (230) est bloquée dans une direction sensiblement perpendiculaire à la direction des lignes d'entrée (4, 4', 4", 4''', ...) ; et
    la direction de l'aimantation de détection (210) est progressivement passée d'une direction initiale sensiblement perpendiculaire à la direction de l'aimantation de stockage (230) à une direction sensiblement parallèle ou antiparallèle à la direction de l'aimantation de stockage (230) en augmentant l'amplitude du signal d'entrée correspondant.
     




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    Cited references

    REFERENCES CITED IN THE DESCRIPTION



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    Patent documents cited in the description