Electronic circuit power supply

Abstract

Electronic Circuit Power Supply This description concerns an electronic circuit power supply device configured to: pass, through a first conductor (251) connected to a node (150), a first current (I1') mirroring a second current (I2) consumed by the electronic circuit; pass a third current (I3) through a second conductor connected to said node, a first branch of a current mirror (174) carrying the third current; pass a fourth constant current (I4) through a third conductor connected to said node; consume a fifth current (I5) mirroring the third current; and regulate a potential of said node (150) by acting on a gate potential of a transistor (T210) electrically in series with a second branch of the current mirror. Figure for the abbreviation: Fig. 2

Description

Title of the invention: Electronic circuit power supply Technical field

[0001] The present description relates generally to electronic devices, and, in particular, to devices and methods for supplying electrical power to electronic circuits. Prior art

[0002] An electronic circuit may be integrated into an electronic chip. The chip typically comprises a device for supplying the electronic circuit, the function of which is to supply a voltage to the electronic circuit from a supply voltage of the chip. The electronic circuit consumes a variable current depending on its operation. The voltage supplied to the circuit is typically stabilized or regulated, so that it maintains a constant value during variations in the current consumed by the circuit.

[0003] The electronic circuit may contain confidential data, which must be protected against access by an unauthorized person. This is the case, for example, when the chip is intended to receive, store and / or communicate passwords or encryption data such as keys. It then happens that an attacker seeks to obtain all or part of the confidential data.

[0004] In one type of attack, the attacker operates the chip and seeks to measure a current supplied to the power supply device of the electronic circuit, with the aim, from variations in this current, of extracting information on the operation of the electronic circuit allowing the confidential information to be deduced. Summary of the invention

[0005] There is a need for a device and method for powering an electronic circuit containing confidential data, making it possible to protect the confidential data against attacks.

[0006] There is a need to simplify existing devices and methods for powering electronic circuits.

[0007] One embodiment overcomes all or part of the drawbacks of known electronic circuit power supply devices.

[0008] One embodiment overcomes all or part of the drawbacks of known methods for powering electronic circuits.

[0009] According to a first aspect, an embodiment provides an electronic circuit power supply device, configured to: - passing, in a first conductor connected to a node, a first current image of a second current consumed by the electronic circuit; - passing a third current in a second conductor connected to said node, a first branch of a current mirror passing the third current; - passing a fourth constant current through a third conductor connected to said node; - consume a fifth current image of the third current; and - regulate a potential of said node by acting on a gate potential of a transistor electrically in series with a second branch of the current mirror.

[0010] One embodiment provides a method of powering an electronic circuit, comprising steps of: - passing, in a first conductor connected to a node, a first current image of a second current consumed by the electronic circuit; - passing a third current in a second conductor connected to said node, a first branch of a current mirror passing the third current; - passing a fourth constant current through a third conductor connected to said node; - consume a fifth current image of the third current; and - regulate a potential of said node by acting on a gate potential of a transistor electrically in series with a second branch of the current mirror.

[0011] According to one embodiment, said transistor connects a node for applying a potential, preferably fixed, to interconnected gates of transistors of the current mirror.

[0012] According to one embodiment, said transistor is smaller than a transistor of the second branch of the current mirror.

[0013] According to one embodiment, the potential of said node is regulated to a constant value.

[0014] According to one embodiment, a resistive element passes the fourth current.

[0015] According to one embodiment, the constant value is that of a regulated potential power supply of the electronic circuit.

[0016] According to one embodiment: - a first branch of another current mirror passes the first current; and - the potential of said node is regulated to a potential value of a terminal of a second branch of said other current mirror.

[0017] According to one embodiment, an operational amplifier receives a potential difference between said node and said terminal of the second branch of said other current mirror and acts on the gate potential of said transistor.

[0018] According to one embodiment, the second branch of said other current mirror is electrically in series with the electronic circuit between a terminal for applying a supply voltage referenced to a reference potential and a terminal for applying the reference potential.

[0019] According to one embodiment, the fifth current is supplied by the terminal for applying the supply voltage.

[0020] According to one embodiment, a terminal of a second branch of said current mirror has a potential regulated to the value of the potential of said node.

[0021] According to one embodiment: - an additional transistor is in series with the second branch of said current mirror; and - the additional transistor is controlled by an output of an operational amplifier receiving a difference between the potential of said node and the potential of said terminal of the second branch of said current mirror.

[0022] According to one embodiment, a ratio between values ​​of the fifth and third currents is equal to another ratio between values ​​of the second and first currents or is equal to the sum of said other ratio and unity.

[0023] One embodiment provides an electronic chip comprising a device as defined above and the electronic circuit, or configured to implement a method as defined above.

[0024] According to a second aspect, an embodiment provides an electronic circuit power supply device, configured to: - passing, in a first conductor connected to a node, a first current image of a second current consumed by the electronic circuit; - passing a third current through a second conductor connected to said node; - regulate a potential of said node to a constant value (VCST) by acting on the third current; - passing a fourth constant current through a third conductor connected to said node; and - consume a fifth current image of the third current.

[0025] One embodiment provides a method of powering an electronic circuit, comprising steps of: - passing, in a first conductor connected to a node, a first current image of a second current consumed by the electronic circuit; - passing a third current through a second conductor connected to said node; - regulate a potential of said node to a constant value by acting on the third current; - pass a fourth constant current through a third connected conductor audit node; and - consume a fifth current image of the third current.

[0026] According to one embodiment, a resistive element passes the fourth current.

[0027] According to one embodiment, the constant value is that of a regulated potential power supply of the electronic circuit.

[0028] According to one embodiment: - a first branch of a current mirror connected to the first conductor passes the first current; and - one terminal of a second branch of the current mirror has a potential regulated to the constant value.

[0029] According to one embodiment, the second branch of the current mirror is electrically in series with the electronic circuit between a terminal for applying a supply voltage referenced relative to a reference potential and a terminal for applying the reference potential.

[0030] According to one embodiment, the fifth current is supplied by the terminal for applying the supply voltage.

[0031] According to one embodiment: - a first branch of a current mirror connected to the second conductor passes the third current; - a second branch of the current mirror connected to the second conductor consumes the fifth current; and - the potential of said node is regulated by an action on a potential of interconnected grids of transistors of the current mirror connected to the second conductor.

[0032] According to one embodiment, the action on the potential of said grids is implemented by an operational amplifier receiving a potential difference between said node and the terminal of the second branch of the current mirror connected to the first conductor.

[0033] According to one embodiment: - the action on the potential of said gates is obtained by acting on a control potential of another transistor electrically in series with a second branch of the current mirror connected to the second conductor; and - preferably, said other transistor connects said gates to another node for applying a supply potential.

[0034] According to one embodiment, said other transistor is smaller than a transistor of the second branch of the current mirror connected to the second conductor.

[0035] According to one embodiment, a terminal of a second branch of the current mirror connected to the second conductor has a potential regulated to the constant value.

[0036] According to one embodiment: - an additional transistor is in series with the second branch of the mirror of current connected to the second conductor; and - the additional transistor is controlled by an output of an operational amplifier configured to amplify a difference between the constant value and the potential of said terminal of the second branch of the current mirror connected to the second conductor.

[0037] According to one embodiment, a ratio between values ​​of the fifth and third currents is equal to another ratio between values ​​of the second and first currents or is equal to the sum of said other ratio and unity.

[0038] One embodiment provides an electronic chip comprising a device as defined above and the electronic circuit, or configured to implement a method as defined above. Brief description of the drawings

[0039] These characteristics and advantages, as well as others, will be explained in detail in the following description of particular embodiments given without limitation in relation to the attached figures among which:

[0040] [Fig-1] [Fig.l] schematically represents an example of a device power supply of an electronic circuit of a type to which the described embodiments apply;

[0041] [Fig.2] [Fig.2] schematically represents an example of a mode of rea lization of an electronic circuit power supply device, according to a first aspect;

[0042] [Fig.3] [Fig.3] schematically represents an example of a mode of rea lization of an electronic circuit power supply device, according to a second aspect; and

[0043] [Fig.4] [Fig.4] schematically represents an embodiment of a electronic circuit power supply device combining the first and second aspects. Description of the embodiments

[0044] The same elements have been designated by the same references in the different figures. In particular, the structural and / or functional elements common to the different embodiments may have the same references and may have identical structural, dimensional and material properties.

[0045] For the sake of clarity, only the steps and elements useful for understanding the described embodiments have been shown and are detailed. In particular, an electronic circuit powered by a power supply device is not described in detail, the described embodiments being compatible with the circuits of conventional electronic chips.

[0046] Unless otherwise specified, when referring to two elements connected between them, it means directly connected without intermediate elements other than conductors, and when we refer to two elements connected (in English "coupled") between them, it means that these two elements can be connected or be linked by means of one or more other elements.

[0047] In the following description, when reference is made to absolute position qualifiers, such as the terms "front", "back", "top", "bottom", "left", "right", etc., or relative position qualifiers, such as the terms "above", "below", "upper", "lower", etc., or to orientation qualifiers, such as the terms "horizontal", "vertical", etc., reference is made unless otherwise specified to the orientation of the figures.

[0048] Unless otherwise specified, the expressions "about", "approximately", "substantially", and "of the order of" mean to within 10%, preferably to within 5%.

[0049] Disclosed embodiments include so-called Metal-Oxide-Semiconductor (MOS) type transistors. Although the MOS type originally referred to transistors having a metal gate and an oxide gate insulator, the MOS type is now, following the development of this type of transistor, understood to encompass field effect transistors whose gate is made of any electrical conductor, and whose gate insulator is made of any dielectric or electrical insulator.

[0050] [Fig.l] schematically represents an example of a power supply device 100 of an electronic circuit 110 (CIRCUIT), of a type to which the described embodiments apply.

[0051] The power supply device 100 and the electronic circuit 110 are typically included in an electronic chip. The electronic chip may consist of a housing, preferably sealed, and one or more wafer portions, preferably semi-conductor, in and on which the device 100 and the circuit 110 are formed. The housing comprises connection pads or pins for connection to other electronic circuits external to the housing, for example to a printed circuit, PCB (in English "Printed Circuit Board"). The electronic chip may also consist of a wafer portion, preferably semi-conductor, in and on which the device 100 and the circuit 110 are located.

[0052] The circuit 110 may be any type of electronic chip circuit. The circuit 110 may comprise several sub-circuits powered in parallel by the device 100. The electronic chip may further comprise other electronic circuits than the circuit 110.

[0053] The device 100 comprises an assembly 120 electrically in series with the electronic circuit 110 between: - a terminal, or node, 130 for applying a supply voltage VCC referenced relative to a reference potential GND, for example a ground; and - a terminal, or node, 132 for applying the reference potential GND. By terminal for applying a voltage referenced to a reference potential, we mean that this voltage is equal to a difference between a potential applied to this terminal and the reference potential. In other words, the voltage VCC corresponds to the potential applied to terminal 130. The voltage VCC can be a voltage supplied to the electronic chip for its operation.

[0054] Typically, the assembly 120 is located, relative to the circuit 110, on the side of the terminal 130 for applying the voltage VCC. For example, the assembly 120 is connected or linked to the terminal 130. Furthermore, the assembly 120 can be connected, preferably connected, to the terminal 132 for applying the reference potential GND.

[0055] The assembly 120 provides the circuit 110, on a connection node 134 between the assembly 120 and the circuit 110, with a voltage VDD referenced to the reference potential GND. In other words, the voltage VDD referenced to the reference potential GND, or potential VDD, is applied to the node 134.

[0056] In the example shown, the voltages VCC and VDD are positive. The supply voltage VCC of the chip is typically between 3.3 V and 5 V, and the voltage VDD provided by the assembly 120 is typically of the order of 1.2 V.

[0057] The assembly 120 may comprise a transistor T121, for example of the P-channel MOS type, connecting the nodes 130 and 134. More precisely, the transistor T121 has its conduction terminals connected, preferably connected, to the respective nodes 130 and 134. By conduction terminals of a transistor, we mean the terminals that the transistor electrically connects together in an on state and electrically isolates from each other in a blocked state. In the example shown, the transistor T121 has a source terminal (S) connected, preferably connected, to the node 130, and a drain terminal (D) connected, preferably connected, to the node 134.

[0058] The assembly 120 may comprise an operational amplifier 122 controlling the transistor T121. In other words, in the example where the transistor T121 is of the MOS type, transistor T121 has a gate connected, preferably connected, to an output of the operational amplifier 122. The operational amplifier 122 thus receives a difference between the voltage VDD supplied to the electronic circuit 110 and a potential VDD0 having a constant value (i.e. constant with respect to the potential GND). More precisely, a non-inverting input (+) of the operational amplifier 122 may be connected, preferably connected, to the node 134, and an inverting input (-) of the operational amplifier 122 may be connected, preferably connected, to a node for applying the constant potential VDD0. Elements providing the potential VDD0 from the voltage VCC are neither described nor shown, the embodiments being compatible with such usual elements.

[0059] In operation, the operational amplifier 122 and the transistor T121 regulate, i.e. stabilize, the voltage VDD supplied to the circuit 110 to a value equal to the constant value of the potential VDDO. In other words, the operational amplifier 122 acts on the control of the transistor T121 in order to maintain the voltage VDD supplied to the circuit 110 at the constant value of the potential VDDO.

[0060] The assembly 120 may comprise a transistor T123 forming a current mirror 124 with the transistor T121.

[0061] By current mirror is meant a circuit comprising two branches provided so that a current in one of the branches is an image of a current in the other of the branches. By currents that are images of each other, is meant that the values ​​of these currents have a constant ratio between them. Preferably, a current mirror comprises, more preferably is constituted by, two MOS transistors with channels of the same conductivity type receiving the same control voltage. By control voltage is meant, in a MOS type transistor, a voltage applied between the gate and the source of the transistor. The transistors of the current mirror are provided, in a usual manner in a current mirror, so that currents flowing in these transistors are, when the potentials of their drains are equal, in a constant ratio, or ratio, equal to a size ratio of the transistors.Preferably, in a current mirror, the two transistors have their gates connected to each other, more preferably connected to each other, and their sources connected to each other, more preferably connected to each other. Preferably, in a current mirror, each transistor defines a branch of the current mirror. Alternatively, the branches may comprise respective resistors having a predefined ratio of values ​​between them.

[0062] The assembly 120 may comprise a transistor T125, for example of the P-channel MOS type. The transistor T125 has, for example, its source connected, preferably connected, to the drain of the transistor T123. The transistor T125 is controlled by an operational amplifier 126. The operational amplifier 126 receives a potential difference between the drain terminals of the transistors T121 and T123 of the current mirror 124. More precisely, the operational amplifier 126 receives, on an inverting input (-), the drain potential of the transistor T123, and, on a non-inverting input (+), the drain potential of the transistor T121.

[0063] In operation, the device consumes a current 10 supplied by the node VCC. The amplifier 126 and the transistor T125 regulate the drain potential of the transistor T123 so that the drain potential of the transistor T123 is equal to that of the drain of the transistor T121. This makes it possible to obtain in the transistor T123 a current II whose value has a constant ratio with a current 12 consumed by the electronic circuit 110. In other words, the current II is an image of the current 12. The currents II and 12 verify the equality II = I2 / K124, where K124 denotes a constant and in which the currents and their values ​​are designated in the same way for the sake of simplicity. Since current 10 is the sum of currents II and 12, currents 10 and II then verify the equality II = I0 / (K124 +1), in other words, current II is also an image of current 10. For example, the constant K124 is between 5 and 200, preferably equal to 100.

[0064] The assembly 120 may further comprise a transistor T127, for example of the N-channel MOS type. The transistor T127 has a drain terminal 128 connected or linked, preferably by the transistor T125, to the drain of the transistor T123. The source of the transistor T127 is connected, preferably connected, to the terminal 132 for applying the reference potential GND. In other words, the transistors T123, T127 and T125 are electrically in series between the terminals 130 and 132. In particular, the transistors T123, T125 and T127 carry the same current II. The transistor T127 has its gate and its drain linked together, preferably connected together.

[0065] The device 100 comprises a node 150. The node 150 is connected to the terminal 132 for applying the reference potential GND by a transistor T145. The transistor T145 may be of the N-channel MOS type. In particular, the transistor T145 has a drain terminal connected, preferably connected, to the node 150, and a source terminal connected, preferably connected, to the terminal 132.

[0066] N-channel transistors T127 and T145 form a current mirror 146. Drain terminal 128 and node 150 constitute the terminals of the respective branches of the current mirror.

[0067] In operation, the branch of the current mirror 146 constituted by the transistor T145 passes a current 11' coming from the node 150.

[0068] The device 100 further comprises a current source 155 connecting the terminal 130 for applying the voltage VCC to the node 150. The current source provides a constant current 14 to the node 150.

[0069] The device 100 comprises a transistor T160 connecting the node 150 to the terminal 132 for applying the reference potential. The transistor T160 may be of the N-channel MOS type, the drain of the transistor T160 being connected, preferably connected, to the node 150, and the source of the transistor T160 being connected, preferably connected, to the terminal 132.

[0070] The device 100 further comprises an assembly 170 controlling the transistor T160. The assembly 170 connects the terminals 130 for applying the voltage VCC and 132 for applying the reference potential GND. The assembly 170 receives a difference between the potentials of the node 150 and the drain terminal 128 of the transistor T127. In other words, the assembly 170 receives a difference between the potentials of the terminals of the branches of the current mirror 146.

[0071] The assembly 170 comprises a transistor T172 forming, with the transistor T160, a current mirror 174. The transistor T172 may be of the N-channel MOS type. The transistor T172 may have its source connected, preferably connected, to the terminal 132 of application of the reference potential GND. The drain of the transistor T172 can be connected or linked, preferably by a transistor T175, to the terminal 130 of application of the potential VCC. The transistor T175 is then in series, between the terminals 130 and 132, with the branch of the current mirror 174 constituted by the transistor T172.

[0072] Preferably, the assembly 170 comprises an operational amplifier 176 controlling the transistor T175. The operational amplifier 176 receives a difference between the potentials of the drains of the transistors of the current mirror 174, in other words, the operational amplifier 176 is configured to amplify this difference. For example, the transistor T175 is of the P-channel MOS type, and the operational amplifier 176 has an inverting input (-) connected, preferably connected, to the node 150, and a non-inverting input (+) connected, preferably connected, to a node 177 for connecting the drains of the transistors T172 and T175 to each other. The node 177 defines a terminal of the branch of the current mirror 174 constituted by the transistor T172.

[0073] In operation, the transistor T160 causes a current 13 to pass from the node 150, in other words, the transistor T160 causes the current 13 to pass. The amplifier 176 and the transistor T175 regulate the potential of the terminal 177 to the value of the potential of the node 150. As a result, the transistor T172 causes a current 15 to pass, image of the current 13 and supplied by the terminal 130 of application of the potential VCC.

[0074] The device 100 further comprises an operational amplifier 178. The operational amplifier 178 receives a potential difference between the node 150 and the drain terminal 128 of the transistor T127. More precisely, the operational amplifier 178 has an inverting input (-) connected, preferably connected, to the drain terminal 128 and a non-inverting input (+) connected, preferably connected, to the node 150. The operational amplifier 178 acts on the potential of the interconnected gates of the transistors T160 and T172 of the current mirror 174. In other words, the output of the operational amplifier 178 is connected, preferably connected, to the gates of the transistors T160 and T172.

[0075] In operation, the operational amplifier 178 regulates the potential of the node 150 to a value equal to that of the potential of the drain terminal 128, by acting on the current 13. As a result, the current 11' is the image of the current II by the current mirror 146. Because the current II is the image of the currents 12 and 10, the current 11' is the image of the currents 10 and 12 and has with the current 10 a ratio of values ​​1 / K, in other words, the current 11' satisfies the relation 11' = I0 / K. For example, the current mirror 146 has a current ratio equal to 1. The ratio 1 / K can be equal to 1 / (K124+1), for example equal to 1 / 101.

[0076] Preferably, transistors T160 and T172 are provided so that current 15 has with current 13 a ratio K inverse to the ratio 1 / K between current 11' and current 10. In other words, the ratio K between the values ​​of currents 15 and 13 is equal to the sum of the unit 1 and the ratio K124 between the values ​​of currents 12 consumed by circuit 110 and 11' in transistor T145. Consequently, the sum I0+I4+I5 of currents 10, 14 and 15 supplied by terminal 130 remains constant, equal to a value (K+1)*I4, whatever the variations of current 12 consumed by electronic circuit 110.

[0077] Thus, an attacker looking for variations in the current 10+15 consumed by the electronic chip to deduce confidential data present in the electronic circuit 110, would not find any variation and would not be able to carry out his attack. The electronic circuit is therefore protected against such attacks.

[0078] According to a first aspect, embodiments of devices and methods for powering an electronic circuit protecting the electronic circuit against the attacks described above, allow, compared to the example of the device 100 of [Fig.l], an improvement in the protection against attacks and / or faster variations in the current 12 supplied to the electronic circuit and / or a reduction in residual variations in the voltage VDD supplied to the circuit.

[0079] According to a second aspect, embodiments of devices and methods for powering an electronic circuit protecting the electronic circuit against the attacks described above, allow, compared to the example of the device 100 of [Fig.l], easier implementation and / or a reduced number of components.

[0080] [Fig. 2] schematically represents an example of an embodiment of a power supply device 200 of an electronic circuit 110 external to the device, according to the first aspect. The circuit 110 is of the type described above in relation to [Fig. 1]. The device 200 and the circuit 110 are preferably included in an electronic chip.

[0081] In the example shown, the device 200 comprises elements identical or similar to those of the device 100 of [Fig. 1], arranged in an identical or similar manner. These elements and their arrangement are not described here again in detail. Only the differences are highlighted.

[0082] The device 200 differs from the device 100 of [Fig.l] in that, in the device 200, the assembly 170 of the device 100 of [Fig.l] is replaced by an assembly 270. Like the assembly 170 of the device 100 of [Fig.l], the assembly 270 has the function of controlling the transistor T160 so as to regulate the potential of the node 150 by acting on the current 13, and to consume a current 15 which is the image of the current 13. In the same way as in the device 100 of [Fig.l], the current 15 consumed by the assembly 270 is added to the current 10 consumed by the electronic circuit 110 and by the assembly 120, so that the total current consumed by the device 200 and the circuit 110 remains constant during the operation of the circuit 110. device 200 thus protects circuit 110 against attacks.

[0083] The assembly 270 of the device 200 differs from the assembly 170 of the device 100 of [Fig.l], in that: - the assembly 270 comprises a transistor T210 electrically in series with the branch of the current mirror 174 defined by the transistor T172. - the operational amplifier 178 of the assembly 170 of [Fig.l] is replaced by an operational amplifier 278. The operational amplifier 278 receives a potential difference between the drain terminal 128 and the node 150, and controls the transistor T210; and - a conduction terminal of transistor T210, located on the side of transistor T175, is connected, preferably connected, to the gates of transistors T172 and T160 of current mirror 174. In other words, transistor T210 connects the gates of transistors T172 and T160 to node 130 of application of potential VCC. Potential VCC is preferably fixed, i.e. constant relative to potential GND.

[0084] In the example shown, the transistor T210 is of the P-channel MOS type. In this example, the source of the transistor T210 is connected, preferably connected, to the node 130 for applying the supply potential VCC. In this example, the amplifier 278 has a non-inverting input (+) connected, preferably connected, to the terminal 128, an inverting input (-) connected, preferably connected, to the node 150 and an output connected, preferably connected, to the gate of the transistor T210.

[0085] Preferably, transistor T175 connects the drains of transistors T210 and T172 together, in other words, transistor T175 is in series with transistors T210 and T172 and is located between transistors T210 and T172.

[0086] In operation, the amplifier 278 acts on the gate potential of the transistor T210. Because the transistor T210 connects the gates of the transistors T172 and T160 to the node 130 for applying the potential VCC, this results in an action on the potential of the interconnected gates of the transistors T172 and T160 of the current mirror 174. This acts on the current 13, so as to regulate the potential of the node 150 to the value of the potential of the drain terminal 128 of the transistor T127. The transistor T160 is thus controlled so as to regulate the potential of the node 150 by acting on the current 13.

[0087] Compared to the device 100 of [Fig.l], the output of the amplifier 278 therefore controls the gate of the transistor T172 via the transistor T210. As mentioned above, the transistor T172 typically has larger dimensions than the transistor T160, in other words, the transistor T160 is smaller than the transistor T172. For example, the ratio between the dimensions of the transistors T172 and T160 is between about 50 and about 200, preferably equal to 101. In particular, the transistor T210 is smaller than the transistor T175.

[0088] As a result, transistor T172 has a relatively small gate parasitic capacitance high compared to that of transistor T210. Because the output of amplifier 278 drives transistor T172 via transistor T210, the drive of transistor T172 by amplifier 278 is faster than the drive of transistor T172 by amplifier 178 of device 100 of [Fig.l].

[0089] As a result, compared to the device 100 of [Fig.l], the current 15 consumed by the device 200 follows more quickly the variations of the current 12 consumed by the circuit 110.

[0090] Because transistor T210 is in series with transistor T172, when a variation in current 12 transiently causes a difference between the potentials of node 150 and the drain of transistor T172, amplifier 278 and transistor T210 act on the potential of the drain of transistor T172 so as to compensate for this difference more quickly than in a circuit such as assembly 170 of device 1a [Fig.l]. In the example shown, if the potential of node 150 increases transiently, transistor T210 becomes more conductive, which contributes to increasing the potential of the drain of transistor T172. In the example shown, if the potential of node 150 decreases transiently, transistor T210 becomes less conductive, which contributes to decreasing the potential of the drain of transistor T172.This helps to make the variations of current 12 follow current 15 more quickly than in a power supply device in which the potential of the gates of transistors T160 and T172 would be controlled by means of a transistor not located in series with transistor T172.

[0091] The fact that the current 15 follows the variations of the current 12 more quickly reduces the duration and the amplitude of transient residual variations of the current consumed by the chip at the times when the current 12 changes value. This makes it possible, for the same speed of the changes in value of the current 12, to reduce the risk of an attacker transiently detecting these residual variations of the current consumed by the chip. Protection against attacks is therefore improved. This also makes it possible, for a given level of protection, that is to say a given level of residual variations of the current consumed by the chip, for the current 12 consumed by the electronic circuit 110 to vary more quickly. The electronic circuit 110 can therefore be faster and / or, by increasing the speed of the operational amplifier 122, a more stable voltage VDD can be provided to the circuit 110.

[0092] The embodiments according to the first aspect are not limited to the particular example described above. In the device 200, the assembly 120 can be replaced by any circuit configured to: - control transistor T145; and - provide a value of the potential of node 150 for which the current 11' in the transistor T145 is the image of the current 12 consumed by the circuit 110.

[0093] In particular, instead of transistor T145 connecting node 150 to terminal 132 of application of the reference potential, a transistor can be provided connecting the node 150 to the terminal 130 of application of the voltage VCC, as described below in relation to [Fig.4]. The current 11' passing, that is to say circulating, in a conductor 251 connected to the node 150 coming from the node 150, is replaced by a current passing in a conductor connected to the node 150 going towards the node 150.

[0094] The assembly 120 and the transistor T145 can thus be replaced by any circuit configured to pass a current in a conductor connected to the node 150, and to provide a value of the potential of the node 150 for which this current is an image of the current 12 consumed by the circuit 110.

[0095] [Fig. 3] schematically represents an embodiment of a power supply device 300 of an electronic circuit 110 external to the device 300, according to a second aspect. The circuit 110 is of the type described above in relation to [Fig. 1]. The device 300 and the circuit 110 are preferably included in an electronic chip. The device 300 comprises elements identical or similar to those of the device 100 of [Fig. 1], which are not described again in detail.

[0096] The device 300 comprises an assembly 320 electrically in series with the electronic circuit 110 between the terminal 130 for applying the voltage VCC and the terminal 132 for applying the reference potential GND. Preferably, the assembly 320 is located, relative to the circuit 110, on the side of the terminal 130 for applying the potential VCC. For example, the assembly 320 is connected to the terminal 130. Furthermore, the assembly 320 can be connected, preferably connected, to the terminal 132 for applying the reference potential GND. The assembly 320 provides the voltage VDD to the circuit 110 on the node 134 defined by the drain terminal of the transistor T121.

[0097] The assembly 320 comprises a transistor T121 and an operational amplifier 122, identical or similar to those of the device 100 of [Fig.l], arranged in an identical or similar manner. In the same manner as in the device 100 of [Fig.l], the operational amplifier 122 and the transistor T121 regulate the voltage VDD supplied to the circuit 110.

[0098] The device 300 comprises a node 150 connected to the terminal 130 for applying the voltage VCC by a transistor T345. The transistor T345 may be of the P-channel MOS type. In particular, the transistor T345 has a drain terminal connected, preferably connected, to the node 150, and a source terminal connected, preferably connected, to the terminal 130.

[0099] The P-channel transistors T121 and T345 form a current mirror 346. The drain terminal 134 of the transistor T121 and the node 150 constitute the terminals of the respective branches of the current mirror 346. Preferably, the sources of the transistors T121 and T345 are connected to each other, more preferably connected to each other, and the The gates of transistors T121 and T345 are connected to each other, more preferably connected to each other. The branch of current mirror 346 constituted by transistor T121 is electrically in series with electronic circuit 110 between terminal 130 for applying the referenced supply voltage VCC and terminal 132 for applying the reference potential GND.

[0100] In operation, the branch of the current mirror 346 constituted by the transistor T345 passes a current 11' directed towards the node 150 in a conductor 351 connected to the node 150 and connected to the current mirror 346.

[0101] The device 300 further comprises a resistive element 355 connecting the node 150 to the terminal 132 for applying the reference potential GND. The resistive element 355 draws a current 14 from the node 150. In other words, the resistive element 355 passes the current 14 into a conductor 352 connected to the node 150. The resistive element 355 may consist of a resistor or several resistors in series and / or in parallel.

[0102] The device 300 comprises a transistor T360 connecting the node 150 to the terminal 130 for applying the voltage VCC. The transistor T360 may be of the P-channel MOS type, the drain of the transistor T360 being connected, preferably connected, to the node 150, and the source of the transistor T360 being connected, preferably connected, to the terminal 130.

[0103] The device 300 further comprises an assembly 370. The assembly 370 connects the terminals 130 for applying the voltage VCC and 132 for applying the reference potential GND. The assembly 370 receives a difference between the potentials of the terminals of the branches of the current mirror 146 (formed by the nodes 150 and 134).

[0104] The assembly 370 comprises a transistor T372 forming, with the transistor T360, a current mirror 374. The transistor T372 may be of the P-channel MOS type. The transistor T372 may have its source connected, preferably connected, to the terminal 130 for applying the voltage VCC. The drain of the transistor T372 may be connected or linked, preferably by a transistor T375, to the terminal 132 for applying the reference potential. The transistor T375 is then in series, between the terminals 130 and 132, with the transistor T372 of the current mirror 374.

[0105] Preferably, the assembly 370 comprises an operational amplifier 376 controlling the transistor T375 and receiving a difference between the potentials of the drains of the transistors of the current mirror 374. For example, the transistor is of the N-channel MOS type, and the operational amplifier 376 has an inverting input (-) connected, preferably connected, to the node 150 and a non-inverting input (+) connected, preferably connected, to a node 377 for connecting the drains of the transistors T372 and T375 to each other. The node 377 constitutes a terminal of the branch of the current mirror 374 defined by the transistor T372.

[0106] In other words, the current mirror 374, the transistor T375, and the amplifier 376 of the device 300 correspond, respectively, to the current mirror 174, to the transistor T175, and to the amplifier 176 of the device 100 of [Fig.l], in which the signs of voltages have been exchanged, the N and P types of conductivity of the channels of the transistors have been exchanged, and the terminals 130 and 132 have been exchanged.

[0107] The operation is therefore similar to that described in relation to [Fig.l]. The transistor T360 passes a current 13 heading towards the node 150 in a conductor 353 connected to the node 150 and connected to the current mirror 374. Amplifier 376 and transistor T375 regulate the potential of terminal 377 to the value of the potential of node 150. The branch of current mirror 374 constituted by transistor T372 consumes a current 15, image of current 13, supplied by terminal 130 of application of potential VCC.

[0108] The device 300 further comprises an operational amplifier 378. The operational amplifier 378 receives a potential difference between the potential of the node 150 and a constant value VCST. More precisely, the operational amplifier 378 has a non-inverting input (+) connected, preferably connected, to the node 150 and an inverting input (-) receiving a potential having the constant value VCST. The output of the operational amplifier 378 is connected, preferably connected, to the gates of the transistors T360 and T372. Thus, the operational amplifier 378 acts on the potential of the interconnected gates of the transistors T360 and T372 of the current mirror 374.

[0109] In operation, the operational amplifier 378 regulates the potential of the node 150 to the constant value VCST by acting on the current 13.

[0110] Because the potential of the node 150 is regulated to a constant value, the current 14 is constant. Compared to the device 100 of [Fig.l], the constant current 14 has thus been obtained in a simpler manner, by replacing the current source 155, intended to provide a current remaining constant when the voltage varies across the terminals of the current source, with a simple resistive element.

[0111] According to one embodiment, the constant value VCST is that of the regulated voltage VDD. In the example shown, the non-inverting input of the amplifier 378 is connected, preferably connected, to the node 134 for applying the voltage VDD. In another example, not shown, the non-inverting input of the amplifier 378 is connected or connected to a node of a potential having the same value as the voltage VDD, such as the potential VDD0, this node being for example the non-inverting input of the amplifier 122.

[0112] Because the constant value VCST, to which the potential of the node 150 is regulated, is equal to the value of the voltage VDD, the current II that the current mirror 346 passes through the conductor 351 is an image of the current 12 consumed by the electronic circuit 110. The current II is therefore an image of a current 10' supplied by the terminal 132, the current 10' being the sum of the currents 11' and 12. More precisely, the current 11' satisfies the relationship 11' = I07(K346+1), where K346 is a ratio between the currents 12 and II'. In other words, current II satisfies the relationship 11' = 107K', with K' = K346+1. The value K' can be between 50 and 200, for example equal to 101.

[0113] Thus, the current 11', the image of the current 10', was passed through the conductor 351 connected to the node 150 without using components such as the transistors T123, T125 and T127 of the device 100 of [Fig.l]. The device 300 is therefore simpler to implement and comprises fewer components than a device such as the device 100 of [Fig.l].

[0114] Transistors T360 and T372 are provided so that currents 15 and 13 have a ratio of values ​​equal to the constant K346. In other words, the ratio between currents 15 and 13 is the same as between currents 12 and II'. As a result, a current 16 supplied by terminal 130, the sum of currents 13 and 15, has with current 13 a ratio K inverse to the ratio 1 / K between current 11' and current 10'. Consequently, the sum I0'+I6 of currents 10 and 16 supplied by terminal 130 remains constant, equal to K*I4, whatever the variations in current 12 consumed by electronic circuit 110. As a result, circuit 110 is protected against the attacks described above.

[0115] The embodiments according to the second aspect are not limited to the particular example described above. In the device 300, the assembly 370 can be replaced by any circuit configured to: - controlling the transistor T360 so as to regulate the potential of the node 150 to the constant value VCST; and - consume a current 15 image of the current 13 circulating in the transistor T360, that is to say pass the current 15 image of the current 13 from one of the terminals 130 and 132 to the other of the terminals 130 and 132.

[0116] Preferably, this circuit replacing the assembly 370 comprises a transistor forming a current mirror with the transistor T360, the transistor T360 constituting a branch of this current mirror. Another branch of this current mirror consumes the current 15. In this other branch, a potential of a drain terminal is regulated to the constant value VCST, so that the two drain terminals of the current mirror have the same potential. Thus, in variants, the inverting input of the amplifier 376 is not connected or linked to the node 150, but is connected or linked to another node whose potential is equal or is regulated to the constant value VCST, such as the nodes 134 for supplying the voltage VDD and the inverting input of the amplifier 122.

[0117] Furthermore, the assembly 320 can be replaced by any circuit configured to control the transistor T345 so as to pass through the transistor T345 a current 11' which is the image of the current 12 when the voltage across the terminals of the transistor T345 has the constant value VCST. Preferably, this circuit replacing the assembly 320 comprises a transistor forming a current mirror with transistor T345, transistor T345 forming one branch of this current mirror. In another branch of this current mirror, a potential of a drain terminal is regulated to the constant value VCST, so that the two drain terminals of the current mirror have the same potential.

[0118] In particular, instead of the transistor T345 connecting the node 150 to the terminal 130 for applying the potential VCC, a transistor such as the transistor T145 ([Fig.l]) can be provided, connecting the node 150 to the terminal 132 for applying the reference potential GND. Like the transistor T345, the transistor T145 passes a current through a conductor connected to the node 150. Thus, an embodiment comprises the same elements as those of the device 100 of [Fig.l], with the difference that: - amplifier 178 ([Fig.l]) receives the constant value VCST on its inverting input - elements are provided in series with transistors T127 and T125 for regulating the voltage of drain terminal 128 of transistor T127 to the constant value VCST; and - preferably, the current source 155 is constituted by a resistive element, which makes it possible to simplify the current source 155.

[0119] The assembly 320 and the transistor T145 can thus be replaced by any circuit configured to pass a current in a conductor connected to the node 150 when the potential of the node 150 has the constant value VCST.

[0120] Furthermore, the resistive element 355 can be replaced by any current source making it possible to obtain the constant current 14 when the voltage across the current source has the constant value VCST. In particular, the resistive element 355 is not necessary to benefit from the advantage, mentioned above, of not using components such as the transistors T123, T125 and T127 ([Fig.l]).

[0121] [Fig. 4] schematically represents an embodiment of a power supply device 400 of an electronic circuit 110 combining the first and second aspects. The circuit 110 is of the type described above in relation to [Fig. 1]. The device 400 and the circuit 110 are preferably included in an electronic chip.

[0122] In the example shown, the device 400 comprises elements identical or similar to those of the device 300 of [Fig. 3], arranged in an identical or similar manner. These elements and their arrangement are not described here again in detail. Only the differences are highlighted.

[0123] The device 400 differs from the device 300 of [Fig. 3] in that, in the device 400, the assembly 370 of the device 300 is replaced by an assembly 470. Like the assembly 370 of the device 300, the assembly 470 has the functions of controlling the transistor T360 so as to regulate the potential of the node 150 by acting on the current 13, and of consuming a current 15 which is the image of the current 13. The device 400 thus protects circuit 110 against attacks.

[0124] The assembly 470 of the device 400 differs from the assembly 370 of the device 300 of [Fig. 3], in that: - assembly 370 comprises a transistor T410 electrically in series with transistor T372; - the operational amplifier 378 of the assembly of [Fig.3] is replaced by an operational amplifier 478. The operational amplifier 478 receives a difference between the constant value VCST and the potential of the node 150, and controls the transistor T410; and - a conduction terminal 412 of transistor T410, located on the side of transistor T375, is connected, preferably connected, to the gates of transistors T372 and T360 of current mirror 374.

[0125] In the example shown, the transistor T410 is of the N-channel MOS type. In this example, the source of the transistor T410 is connected, preferably connected, to the terminal 132 for applying the reference potential GND. In this example, the amplifier 478 has: - a non-inverting input (+) connected, preferably connected, to node 134 or to a node applying a potential equal to, or regulated to, the constant value; - an inverting input (-) connected, preferably connected, to node 150; and - an output connected, preferably connected, to the gate of transistor T410. In other words, transistor T410 connects the gates of transistors T372 and T360 to node 132 of application of the fixed potential GND.

[0126] In operation, the amplifier 478 acts on the gate potential of the transistor T410. This results in an action on the current 13 in the transistor T360, so as to regulate the potential of the node 150 to the constant value VCST. The transistor T360 is thus controlled so as to regulate the potential of the node 150 by acting on the current 13.

[0127] Compared to the device 300 of [Fig. 3], in the device 400, the output of the amplifier 478 therefore controls the gate of the transistor T372 via the transistor T410. The transistor T410 is smaller than the transistor T372. In the same way as for the device 200 of [Fig. 2], the control of the transistor T372 by the amplifier 478 is faster than the control of the transistor T372 by the amplifier 378 of the device 300 of [Fig. 3].

[0128] In the same way as for the device 200 of [Fig.2], in the device 400, compared to the device 300 of [Fig.3], because the control of the transistor T372 is faster and because the transistor T410 is in series with the transistor T372, the current 15 consumed by the device 400 follows more quickly the variations of the current 12 consumed by the circuit 110. This allows, compared to the device 300 of [Fig.3], an improvement in protection against attacks and / or faster variations in the current 12 supplied to the electronic circuit and / or a reduction in residual variations in the voltage VDD supplied to the circuit.

[0129] Various embodiments and variations have been described. Those skilled in the art will understand that certain features of these various embodiments and variations could be combined, and other variations will occur to those skilled in the art. In particular, although positive VCC and VDD voltages have been described above, those skilled in the art will know how to adapt the embodiments described above to negative VCC and / or VDD voltages, for example by exchanging the N and P types of the channel conductivities of the transistors, by exchanging the inverting and non-inverting inputs of the operational amplifiers, and by reversing the directions of the currents.

[0130] Furthermore, embodiments have been described in which transistors are controlled by operational amplifiers. The person skilled in the art will know, depending on supply voltages of the amplifiers and properties of the amplifiers and transistors, how to implement embodiments in which the N and P types of channel conductivity of one or more of these transistors are exchanged, the inverting and non-inverting inputs of the amplifier(s) concerned being exchanged.

[0131] Finally, the practical implementation of the embodiments and variants described is within the reach of those skilled in the art from the functional indications given above.

Claims

Claims

1. Method for powering an electronic circuit, (11° comprising steps consisting of: - passing, in a first conductor (251; 351) connected to a node (150), a first current (II1) image of a second current (12) consumed by the electronic circuit; - passing a third current (13) in a second conductor (353) connected to said node, a first branch of a current mirror (174; 374) passing the third current; - passing a fourth constant current (14) in a third conductor (352) connected to said node; - consuming a fifth current (15) image of the third current; and - regulating a potential of said node (150) by acting on a gate potential of a transistor (T210; T410) electrically in series with a second branch of the current mirror.

2. Method according to claim 1, wherein said transistor (T210; T410) connects a node (132; 130) for applying a potential, preferably fixed, to interconnected gates of transistors (T160, T172; T360, T372) of the current mirror (174; 374).

3. The method of claim 1 or 2, wherein said transistor (T210; T410) is smaller than a transistor (T172; T372) of the second branch of the current mirror (174; 374).

4. A method according to any one of claims 1 to 3, wherein the potential of said node (150) is regulated to a constant value (VCST).

5. The method of claim 4, wherein a resistive element (355) passes the fourth current (14).

6. Method according to claim 4 or 5, in which the constant value (VCST) is that of a regulated potential (VDD) supplying the electronic circuit (110).

7. Method according to any one of claims 1 to 6, in which: - a first branch of another current mirror (146; 346) passes the first current (II1); and - the potential of said node (150) is regulated to a value of potential of a terminal (128; 134) of a second branch of said other current mirror.

8. Method according to claim 7, in which an operational amplifier (278; 478) receives a potential difference between said node (150) and said terminal (128; 134) of the second branch of said other current mirror and acts on the gate potential of said transistor (T210; T410).

9. Method according to claim 7 or 8, in which the second branch of said other current mirror (346) is electrically in series with the electronic circuit (110) between a terminal (130) for applying a supply voltage (VCC) referenced with respect to a reference potential (GND) and a terminal (132) for applying the reference potential.

10. Method according to claim 9, in which the fifth current (15) is supplied by the terminal (130) for applying the supply voltage.

11. A method according to any one of claims 8 to 10, wherein a terminal (177; 377) of a second branch of said current mirror (174; 374) has a potential regulated to the value of the potential of said node (150).

12. Method according to any one of claims 1 to 11, wherein: - an additional transistor (T175; T375) is in series with the second branch of said current mirror (174; 374); and - the additional transistor is controlled by an output of an operational amplifier (176) receiving a difference between the potential of said node (150) and the potential of said terminal (177; 377) of the second branch of said current mirror.

13. A method according to any one of claims 1 to 12, wherein a ratio between values ​​of the fifth (15) and third (13) currents is equal to another ratio between values ​​of the second (12) and first (II1) currents or is equal to the sum of said other ratio and unity.

14. Device (200; 400) for supplying an electronic circuit (110), configured to implement the method according to any one of claims 1 to 13.

15. An electronic chip comprising a device according to claim 14 and the electronic circuit (110).

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