Overvoltage protection

Abstract

Embodiments of this disclosure disclose overvoltage protection. This disclosure relates to a device including a rectifier bridge, the rectifier bridge comprising: a branch connected between a first node and a second node; another branch including a first MOS transistor and a second MOS transistor connected in series between the first node and the second node and having their sources coupled together; a resistor connecting the gate of the first transistor to the second node; another resistor connecting the gate of the second transistor and the first node; and a circuit, for each transistor, including a first terminal and a second terminal respectively connected to the drain and gate of the transistor, and configured to electrically couple the first terminal and the second terminal of the circuit when the voltage between the first terminal of the circuit and the first terminal of the other circuit is greater than a threshold value of the circuit.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to French application number 20 / 01096, filed on February 4, 2020, which is incorporated herein by reference. Technical Field

[0003] This disclosure generally relates to electronic circuits, and more specifically, to preventing overvoltages that can occur between pads of such electronic circuits (especially after electrostatic discharge). Background Technology

[0004] A wireless communication device capable of communicating using electromagnetic waves, such as radio frequency waves. When the antenna of the first device receives electromagnetic waves emitted by the second device, the power received by the antenna of the first device can be used to power the circuitry (e.g., integrated circuit) of the first device. For this purpose, the first device typically includes a rectified voltage bridge configured to receive the voltage available between two pads or terminals at respective ends of a conductive winding coupled to the antenna of the first device, and to transmit the rectified power supply voltage.

[0005] However, overvoltages, such as those caused by electrostatic discharge, can occur between the two pads at the respective ends of the conductive winding coupled to the antenna. Such overvoltages can degrade, or even damage, the circuitry of the first device coupled to at least one of the two pads, particularly the rectifier bridge coupled to the pad. Summary of the Invention

[0006] There is a need to overcome all or part of the shortcomings of known wireless communication devices, particularly regarding the protection of these devices from overvoltages (e.g., overvoltages caused by electrostatic discharge) that can occur between the pads at the corresponding ends of the conductive windings coupled to the antenna.

[0007] One embodiment overcomes all or some of the disadvantages of known wireless communication devices.

[0008] One embodiment overcomes all or part of the disadvantages of known wireless communication devices caused by, for example, overvoltages due to electrostatic discharge, which can occur between pads at the respective ends of the conductive windings of the antenna coupled to these devices.

[0009] One embodiment overcomes all or part of the disadvantages of known voltage rectifier bridges, which are configured to rectify the voltage available between two pads at respective ends of a conductive winding coupled to an antenna of a wireless communication device.

[0010] One embodiment provides a device including a rectifier bridge, the rectifier bridge comprising: a first branch connected between a first input node and a second input node of the bridge and including a third output node of the bridge; a second branch including a first MOS transistor and a second MOS transistor connected in series between the first node and the second node, the sources of the first transistor and the second transistor being coupled to a fourth output node of the bridge; a first resistor connected between the gate of the first transistor and the second node; a second resistor connected between the gate of the second transistor and the first node; and a circuit, for each of the first transistor and the second transistor, the circuit being associated with the transistor and including a first terminal connected to the drain of the transistor and a second terminal connected to the gate of the transistor, the circuit being configured to electrically couple the first terminal and the second terminal of the circuit when the absolute value of a voltage between the first terminal of the circuit and the first terminal of another circuit is greater than or equal to the absolute value of a threshold of the circuit and the voltage has the same sign as the threshold.

[0011] According to one embodiment, each circuit is further configured to electrically isolate the first and second terminals of the circuit when the absolute value of the voltage between the first terminal of the circuit and the first terminal of another circuit is less than the absolute value of a threshold of the circuit, and when the voltage has a sign opposite to the sign of the threshold of the circuit.

[0012] According to one embodiment, the first branch of the bridge includes a third MOS transistor and a fourth MOS transistor connected in series between a first node and a second node, and each is assembled into a diode, with the sources of the third transistor and the fourth transistor connected to the third node.

[0013] According to one embodiment, the first transistor, the second transistor, the third transistor, and the fourth transistor have the same N-channel or P-channel.

[0014] According to one embodiment, each circuit includes a branch, the branch including a first dipole with diode function and a second dipole with diode function that are anti-series coupled, one end of the branch being connected to a first terminal of the circuit, and the other end of the branch being connected to a first terminal of another circuit.

[0015] According to one embodiment, in each circuit, a first dipole and a second dipole are configured to: block current when the absolute value of the voltage between a first terminal of the circuit and a first terminal of another circuit is less than the absolute value of a threshold of the circuit and when the voltage has a sign opposite to the threshold of the circuit, and conduct current when the absolute value of the voltage between a first terminal of the circuit and a first terminal of another circuit is greater than or equal to the absolute value of a threshold of the circuit and when the voltage has the same sign as the threshold.

[0016] According to one embodiment, each circuit is configured such that conduction of current in the first dipole of the circuit causes electrical coupling between the first terminal and the second terminal of the circuit.

[0017] According to one embodiment, in at least one circuit in the circuit, preferably in each circuit, the other end of the circuit branch is connected to a second terminal of the circuit.

[0018] According to one embodiment, in at least one circuit of the circuit, preferably, in each circuit, the branches of the circuit include: a fifth node, a sixth node, and a seventh node; a third resistor connected in series with a first dipole between the fifth node and the sixth node; and a fourth resistor connected between the sixth node and the seventh node. Each circuit also includes a transistor having a control terminal connected to the sixth node and conductive terminals connected to the fifth node and the seventh node, respectively. The voltage drop in the fourth resistor regulates the conduction of the transistor.

[0019] According to one embodiment, in at least one circuit in the circuit, preferably in each circuit: a second dipole is connected between a first terminal and a fifth node of the circuit, and a seventh node is connected to a second terminal of the circuit; or a second dipole is connected between a seventh node and a second terminal of the circuit, and a fifth node is connected to a first terminal of the circuit; or a second dipole is connected between a first terminal and a seventh node of the circuit, and a fifth node is connected to a second terminal of the circuit; or a second dipole is connected between a fifth node and a second terminal of the circuit, and a seventh node is connected to a first terminal of the circuit.

[0020] According to one embodiment, in at least one circuit, preferably in each circuit, the other end of a circuit branch is connected to a third terminal of the circuit, and the third terminal of the circuit is connected to a first terminal of another circuit.

[0021] According to one embodiment, in at least one circuit, preferably in each circuit, the branch includes a third resistor connected in series with the first dipole and the second dipole, each circuit also includes a transistor having a control terminal connected to the terminal of the third resistor, a first conductive terminal coupled to the first terminal of the circuit, and a second conductive terminal coupled to the second terminal of the circuit, wherein the voltage drop in the third resistor regulates the conduction of the transistor.

[0022] According to one embodiment, in at least one circuit, preferably in each circuit, a second dipole is connected between a first terminal of the circuit and a first conductive terminal of the transistor, and a second conductive terminal of the transistor is connected to a second terminal of the circuit.

[0023] According to one embodiment, at least one circuit, preferably each circuit, further includes a third dipole having diode function, the third dipole being connected in series with a transistor of the circuit between the first and second terminals of the circuit, the third dipole being connected to the second terminal of the circuit, and a branch of the circuit being connected between the first and third terminals of the circuit.

[0024] According to one embodiment, the first dipole is formed by a Zener diode, an assembly of a plurality of Zener diodes connected in parallel, or an assembly of a plurality of MOS transistors connected in series, each MOS transistor being an assembled diode.

[0025] Another embodiment provides an integrated circuit that includes the device as described. Attached Figure Description

[0026] The above-described features and advantages, as well as other features and advantages, will be described in detail in the following description of specific embodiments given by way of illustration rather than limitation with reference to the accompanying drawings, in which:

[0027] Figure 1 A portion of an example device, including a rectifier bridge, is shown in circuit form;

[0028] Figure 2 Multiple curves illustrating the conduction operation of different MOS transistors are shown;

[0029] Figure 3 A portion of a device including a rectifier bridge according to one embodiment is shown in circuit form;

[0030] Figure 4 A portion of a device including a rectifier bridge according to another embodiment is shown in circuit form;

[0031] Figure 5 A portion of a device including a rectifier bridge according to yet another embodiment is shown in circuit form; and

[0032] Figure 6 A portion of a device including a rectifier bridge according to yet another embodiment is shown in circuit form. Detailed Implementation

[0033] In the various figures, the same features have been indicated by the same reference numerals. In particular, common structural and / or functional features in various embodiments may have the same reference numerals and may have the same structure, dimensions, and material properties.

[0034] For clarity, only steps and elements useful for understanding the embodiments described herein are described in detail. In particular, various wireless communication protocols, especially those via radio frequency waves and their implementations, are not described in detail; the described embodiments are compatible with known wireless communication protocols and known implementations of such protocols. Furthermore, the functionality implemented by a known device comprising a voltage rectifier bridge coupled to two pads of the device, with a voltage to be rectified available between the two pads, is not described; the described embodiments are compatible with the general functionality of such known devices.

[0035] Unless otherwise indicated, when referring to two elements connected together, it means that there is no direct connection of any intermediate element other than a conductor, and when referring to two elements coupled together, it means that the two elements can be connected or they can be coupled via one or more other elements.

[0036] In the following disclosure, unless otherwise indicated, when referring to absolute positional qualifiers such as terms “front,” “back,” “top,” “bottom,” “left,” “right,” etc., or relative positional qualifiers such as terms “up,” “down,” “high,” “low,” etc., or orientational qualifiers such as “horizontal,” “vertical,” etc., refer to the orientation shown in the figures.

[0037] Unless otherwise stated, expressions “approximately,” “about,” “basically,” and “in the order of” indicate within 10%, and preferably within 5%.

[0038] In the following description, unless otherwise indicated, all potentials and voltages are relative to the same reference potential, typically ground (GND), or in other words, zero reference voltage.

[0039] Figure 1 A portion of device 1, including rectifier bridge 2, is shown in circuit form.

[0040] In this example, device 1 is a wireless communication device including a conductive antenna winding or inductor or coil (not shown), the ends of which are connected to pads or terminals 101 and 102 of device 1, respectively. In the following description, device 1 is a radio frequency communication device; for example, the case of near field communication or NFC device 1 is considered as an example.

[0041] For example, an N-channel MOS (metal-oxide-semiconductor) transistor (not shown) can be connected between pad 101 and pad 102 to achieve reverse modulation of the electromagnetic field received by the antenna of device 1. The reverse-modulation MOS transistor has a first conductive terminal, such as its source coupled (preferably connected) to pad 102, and a second conductive terminal, such as its drain coupled (preferably connected) to pad 101.

[0042] For example, a capacitor (not shown) may be placed between pads 101 and 102 to adjust the resonant frequency of the antenna of device 1.

[0043] Figure 1 The voltage rectifier bridge 2 of device 1 is shown in more detail.

[0044] Bridge 2 is coupled to pads 101 and 102 to receive the voltage Vin to be rectified. The voltage Vin corresponds to the difference between the potential of node 102 and the potential of node 101, and in this example, the voltage references node 101. As an example, the voltage Vin has a maximum amplitude of less than 6V, for example, equal to 5.5V (the voltage Vin ranges from -5.5V to +5.5V, for example).

[0045] Rectifier bridge 2 is configured to deliver the rectified power supply voltage Vout to the circuitry of device 1 (not shown). Voltage Vout corresponds to the difference between the potential of output node 206 of bridge 2 and the potential of output node 210 of bridge 2, and in this example, voltage Vout refers to node 210. In this example, node 210 is at a reference potential GND, typically ground.

[0046] The rectifier bridge 2 includes two nodes or terminals 201 and 202 coupled to corresponding pads 101 and 102. In the example shown, nodes 201 and 202 are connected to corresponding pads 101 and 102. According to another example not shown, nodes 201 and 202 are coupled to pads 101 and 102 respectively via low-value resistors (typically a few ohms).

[0047] The rectifier bridge 2 includes two branches connected in parallel between input nodes 201 and 202.

[0048] One of the two branches includes two N-channel MOS transistors 203 and 204 connected in series between nodes 201 and 202. Transistors 203 and 204 are connected to each other at the level of node 206 of bridge 2, or in other words, each of transistors 203 and 204 is connected to node 206. Each transistor 203, 204 is a diode-assembled, meaning its gate and drain are connected to each other. In the example shown, the drain and gate of transistor 203 are connected to node 202, the drain and gate of transistor 204 are connected to node 201, and the sources of transistors 203 and 204 are connected to node 206, or in other words, connected together at the level of node 206.

[0049] According to another example not shown, each of transistors 203 and 204 can be replaced with a diode, for example, by replacing transistor 203 with a diode whose anode is connected to node 202 and whose cathode is connected to node 206, and replacing transistor 204 with another diode whose anode is connected to node 201 and whose cathode is connected to node 206.

[0050] Another branch of rectifier bridge 2 includes two N-channel MOS transistors 208 and 209 connected in series between nodes 201 and 202. Transistors 208 and 209 are connected to each other at the same voltage level as node 210 of rectifier bridge 2; in other words, each of transistors 208 and 209 is connected to node 210. For example, the drain of transistor 208 is connected to node 202, its source to node 210, and its gate to node 201; similarly, the drain of transistor 209 is connected to node 201, its source to node 210, and its gate to node 202.

[0051] Transistors 208 and 209 couple their body regions or channel forming regions, preferably to node 210, at the potential of node 210.

[0052] In operation, when AC voltage Vin is available between pads 101 and 102, and therefore in this example, when it is available between nodes 201 and 202, rectifier bridge 2 delivers rectified voltage Vout. Specifically, when the potential of node 202 is sufficiently greater than the potential of node 201, transistors 203 and 209 are turned on, and transistors 204 and 208 are turned off. Conversely, when the potential of node 201 is sufficiently greater than the potential of node 202, transistors 203 and 209 are turned off, and transistors 204 and 208 are turned on.

[0053] Consider an overvoltage occurring between pad 102 and pad 101, and therefore between nodes 201 and 202. This overvoltage corresponds, for example, to an increase in the potential of pad 102 relative to the potential of pad 101, or a positive overvoltage. According to the human body model or HBM, a positive overvoltage may arise, for example, from electrostatic discharge on pad 102, such as an electrostatic discharge of 1.5 kV or even 2 kV. This electrostatic discharge may be caused, for example, by a person touching pad 102 or by the conductive antenna winding of device 1 coupled to pad 102.

[0054] This positive overvoltage between pads 102 and 101 results in a significant current, for example at least 1A, flowing between pads 102 and 101, for example from pad 102 to node 210 via transistor 208, and a positive current flowing from node 210 to pad 101 via a forward bias diode between the substrate (body) and the drain of transistor 209.

[0055] Since the gate and source of transistor 208 are essentially at the same potential, i.e., the potential at node 210, transistor 208 should be off. However, when the potential difference between the drain and source of MOS transistor 208 exceeds a threshold known as the snapback threshold, the parasitic bipolar transistor of MOS transistor 208 begins to conduct, and current flows from the drain to the source of MOS transistor 208. This current then flows to node 201 via the forward diode between the body (substrate) region and the drain of transistor 209. The current conduction between the drain and source of transistor 208 has a negative differential impedance between the conductive terminals of transistor 208, which causes a problem.

[0056] This problem arises when the MOS transistor 208 is implemented using multiple basic MOS transistors connected in parallel. In practice, due to manufacturing dispersion, the fast-return threshold of the first basic transistor may be lower than the fast-return threshold of all the other basic transistors. Therefore, the parasitic bipolar transistor of the first basic MOS transistor turns on before the parasitic bipolar transistors of the other basic MOS transistors turn on. Then, all the current flowing through the MOS transistor 208 flows through the first basic MOS transistor, which may cause degradation or even damage to the first basic MOS transistor.

[0057] Although not detailed, the problem related to transistor 208 during the positive overvoltage period between pad 102 and pad 101, as shown above, is addressed symmetrically to transistor 209 during the overvoltage period between pad 102 and pad 101, which corresponds to an increase in the potential of node 201 relative to the potential of node 202, or a negative overvoltage.

[0058] To overcome all or part of the drawbacks of rectifier bridge 2, the inventors hereby provide a so-called conduction circuit associated with each of transistors 208 and 209, the conduction circuit having a first terminal and a second terminal respectively connected to the drain and gate of transistor 208 or 209, which has associated circuitry. Furthermore, a resistor is connected between the gate of transistor 208 and node 201 (drain of transistor 209), and another resistor is connected between the gate of transistor 209 and node 202 (drain of transistor 208).

[0059] Each conducting circuit is configured to electrically couple its first and second terminals when the voltage between its first terminal and the first terminal of another circuit is greater than or equal to a threshold value of the circuit. In other words, the first conducting circuit associated with transistor 208 is configured to electrically couple its first and second terminals when the voltage between its first terminal (drain of transistor 208 - node 202) and the first terminal of the second conducting circuit associated with transistor 209 (drain of transistor 209 - node 201) exceeds the threshold value of the first circuit, and the second circuit is configured to electrically couple its first and second terminals when the voltage between its first terminal and the first terminal of the first circuit exceeds the threshold value of the second circuit. The voltage between the first terminal of this circuit and the first terminal of the other circuit exceeding the considered conduction threshold represents an overvoltage between nodes 201 and 202.

[0060] Furthermore, each conducting circuit is configured to electrically isolate or decouple its first and second terminals from each other when the voltage between the first terminal of the circuit and the first terminal of another circuit is less than a threshold value of the circuit. In other words, the first circuit is configured to electrically isolate its first and second terminals when the voltage between the first terminals of the first circuit and the first terminals of the second circuit is less than a threshold value of the first conducting circuit, and the second circuit is configured to electrically isolate its first and second terminals when the voltage between the first terminals of the second circuit and the first terminals of the first circuit is less than a threshold value of the second circuit. Therefore, in the absence of overvoltage between nodes 201 and 202, the operation of the rectifier bridge is not altered by the presence of the conducting circuits and is similar to that of a combined circuit. Figure 1 The operation of rectifier bridge 2 is described.

[0061] In the following description and claims, the term "dipole with diode function" refers to a component or circuit having two terminals, between which the component or circuit functions as a diode. One terminal of the dipole is called the cathode, and the other terminal is called the anode. The dipole exhibits the same behavior between its anode and cathode as a diode does between its anode and cathode.

[0062] According to one embodiment, each conducting circuit includes a branch comprising a first dipole with diode function and an anti-series coupled second dipole with diode function. One end of the branch is connected to a first terminal of the conducting circuit, while the other end of the branch is coupled to a first terminal of another conducting circuit. The term "branch" including a first dipole and a second dipole with diode function and anti-series coupled indicates that in this branch, the anodes of the first dipole and the second dipole are coupled together, or their cathodes are coupled together.

[0063] According to one embodiment, each conducting circuit includes a third terminal connected to a first terminal of another circuit. In this embodiment, in each conducting circuit, a branch including an anti-series first dipole and a second dipole is connected between the first and third terminals of the circuit; or in other words, one end of the branch is connected to the first terminal of the circuit, and the other end of the branch is connected to the third terminal of the circuit.

[0064] According to another embodiment, in each conducting circuit, a branch including an anti-series first dipole and a second dipole is connected between the first terminal and the second terminal of the circuit, or in other words, one end of the branch is connected to the first terminal of the circuit, and the other end of the branch is connected to the second terminal of the circuit.

[0065] According to one embodiment, in each conducting circuit, a first dipole and a second dipole are configured to block current when the voltage between a first terminal of one circuit and a first terminal of another circuit is less than a threshold value of the circuit.

[0066] According to one embodiment, in each conducting circuit, the first dipole and the second dipole are further configured to conduct current when the voltage between the first terminal of the circuit and the first terminal of the other circuit is greater than or equal to a threshold value of the circuit.

[0067] According to one embodiment, each conducting circuit is configured such that the conduction of current in the first dipole of the circuit causes electrical coupling between the first terminal and the second terminal of the circuit.

[0068] According to one embodiment, in each conducting circuit, the forward conduction threshold of the second dipole and the reverse conduction threshold of the first dipole at least partially determine the threshold of the conducting circuit. The term "forward conduction threshold of a diode-functional dipole" designates the voltage value above which the dipole anode is relative to the dipole cathode, at which the dipole conducts positive current from its anode to its cathode. Similarly, the term "reverse conduction threshold of a diode-functional dipole" designates the voltage value above which the dipole cathode is relative to the dipole anode, at which the dipole conducts positive current from its cathode to its anode.

[0069] Figure 2 Curves C0, C2, C3, C4, C5, and C6 are shown, illustrating different conduction states of a MOS transistor (N-channel in this example). Each curve illustrates the change in the drain-source current Is as the transistor's source is grounded (GND) and the drain potential (Vd) increases. Each curve corresponds to a different potential applied to the transistor's gate.

[0070] Figure 2Curve C0 illustrates the case where the potential applied to the transistor gate is zero, or in other words, equal to ground potential GND. When the transistor's drain potential Vd increases above the fast-return threshold Vsb, the transistor then exhibits a negative differential impedance between its conductive terminals. More specifically, as long as the potential Vd is below the threshold Vsb, the current Is is zero or close to zero. Furthermore, after the potential Vd has reached the threshold Vsb, a non-zero current Is flows through the transistor, increasing as the potential Vd decreases due to the transistor's negative differential impedance.

[0071] Curves C2, C3, C4, C5, and C6 show the case where the potential applied to the transistor gate is non-zero. This potential is higher for curve C3 than for curve C2, higher for curve C4 than for curve C3, higher for curve C5 than for curve C4, and higher for curve C6 than for curve C5.

[0072] It can be observed that, for curve C2, the transistor under consideration still exhibits a negative differential impedance; that is, the curve shows a portion where the current Is increases while the potential Vd decreases, but the negative impedance value is less than that of curve C0. For curves C3, C4, C5, and C6, this negative differential impedance is suppressed.

[0073] Furthermore, it can be observed that the higher the potential on the transistor gate, the lower the maximum value that potential Vd can take.

[0074] It can also be observed that for a given potential value Vd, the higher the potential on the transistor gate, the higher the current Is value.

[0075] Therefore, conduction circuits associated with each of transistors 208 and 209 are provided such that during an overvoltage period between nodes 201 and 202 that causes an increase in the drain potential of one of the transistors, the conduction circuits associated with the transistors can cause a corresponding increase in the gate potential of the transistors. Thus, the transistors operate as shown by curves C3, C4, C5, and C6, no longer having negative differential impedance. Furthermore, for a given drain potential, the higher the gate potential of the transistor during an overvoltage period between nodes 201 and 202, the higher the current Is flowing between the conductive terminals of the transistor, thus allowing for more effective overvoltage prevention.

[0076] Now we will combine Figures 3 to 6 Several embodiments and variations of the conduction circuit are described.

[0077] Figure 3 A portion of a device 3, including a rectifier bridge 4, is shown in circuit form. The rectifier bridge 4 is provided with a conduction circuit according to one embodiment.

[0078] Device 3 is similar to Figure 1Regarding device 1, only the differences between device 1 and device 3 will be detailed here.

[0079] More specifically, device 3 differs from device 1 in that its voltage rectifier bridge 4 is different from voltage rectifier bridge 2. Compared to rectifier bridge 2, rectifier bridge 4 includes a resistor R1 connected between node 201 and the gate of transistor 208, and a resistor R2 connected between node 202 and the gate of transistor 209. A further difference between rectifier bridge 4 and rectifier bridge 2 is that, for each of transistors 208 and 209, rectifier bridge 4 includes a conduction circuit 300 associated with the transistor. Each circuit 300 includes a first terminal 301 and a second terminal 302. Terminal 301 of the circuit 300 associated with transistor 208 (209, respectively) is connected to the drain of transistor 208 (209, respectively), and its terminal 302 is connected to the gate of transistor 208 (209, respectively).

[0080] Each circuit 300 includes a branch comprising a first dipole with diode function D1 and a second dipole with diode function D2, which are anti-series coupled together.

[0081] exist Figure 3 In the illustrated embodiment, in each circuit 300, branches including anti-series dipoles D1 and D2 are connected between terminals 301 and 302 of the circuit, or in other words, one end of the circuit is connected to terminal 301 and the other end is connected to terminal 302 of the circuit 300.

[0082] exist Figure 3 In one example, in each circuit 300, the cathodes of dipoles D1 and D2 are connected together and their anodes are connected to terminals 301 and 302, respectively. In another example, not shown, in each circuit 300, the anodes of dipoles D1 and D2 are connected together and their cathodes are connected to terminals 301 and 302, respectively.

[0083] The normal operation of bridge 4, i.e., when there is no overvoltage between nodes 201 and 202, is as follows. Since there is no overvoltage between nodes 201 and 202, the voltage between nodes 202 and 201 (the voltage of node 202 relative to node 201) is less than the threshold of circuit 300 associated with transistor 208, and the voltage between nodes 201 and 202 (the voltage of node 201 relative to node 202) is less than the threshold of circuit 300 associated with transistor 209. Then, dipoles D1 and D2 of circuit 300 associated with transistor 208 (and 209 respectively) block the flow of current between terminals 301 and 302 of the circuit associated with transistor 208 (and 209 respectively), and block current through resistors R1 (and R2 respectively). Therefore, the potential of node 202 (and 201 respectively) exists at the gate of transistor 209 (and 208 respectively).

[0084] More specifically, in Figure 3 In the example, when the potential of node 202 is greater than the potential of node 201, the dipole D2 of circuit 300 associated with transistor 209 is reverse biased and is equivalent to an open circuit. Furthermore, the dipole D1 of circuit 300 associated with transistor 208 is also reverse biased, but the voltage across it is less than its reverse conduction voltage, thus dipole D2 is equivalent to an open circuit. Moreover, once the voltage between nodes 202 and 201 becomes greater than the threshold voltage of transistor 209, transistor 209 switches to the on state and electrically couples node 201 to node 210, while transistor 208 is in the off state.

[0085] When the potential of node 201 is greater than that of node 202, the normal operation of bridge 4 can be derived from the above operation through symmetry.

[0086] During an overvoltage period between nodes 201 and 202, bridge 4 operates as follows. A positive overvoltage case is considered as an example. Transistor 209 and its associated circuit 300 then behave normally; in other words, circuit 300 associated with transistor 209 is equivalent to an open circuit between its terminals 301 and 302, and transistor 209 is turned on. Furthermore, once the voltage between nodes 202 and 201 becomes greater than the threshold voltage of circuit 300 associated with transistor 208, current flows through dipoles D1 and D2 of the circuit and through resistor R1. Therefore, the gate potential of transistor 208 increases with the potential of node 202. In other words, the potential at the gate of transistor 208 is then equal to the potential of node 202 minus the voltage drop in dipoles D1 and D2 of circuit 300 associated with transistor 208. Figure 3 In the example, the threshold of each circuit 300 is equal to the sum of the reverse conduction threshold of dipole D1 and the forward conduction threshold of dipole D2.

[0087] The operation of bridge 4 under negative overvoltage conditions between nodes 201 and 202 can be derived from the operation under positive overvoltage conditions described above using symmetry.

[0088] Figure 4 A portion of a device 3-1, including a rectifier bridge 4-1, is shown in circuit form according to another embodiment.

[0089] Equipment 3-1 is similar to Figure 3 Device 3 is described in detail here, focusing only on the differences between Device 3-1 and Device 3. More specifically, Device 3-1 differs from Device 3 in that its voltage rectifier bridge 4-1, unlike voltage rectifier bridge 4, includes conduction circuits 300-1 instead of each circuit 300 of rectifier bridge 4. Each circuit 300-1 includes a first terminal 301 and a second terminal 302. Terminal 301 of the circuit 300-1 associated with transistors 208 (209, respectively) is connected to the drain of transistor 208 (209, respectively), and its terminal 302 is connected to the gate of transistor 208 (209, respectively).

[0090] Each circuit 300-1 includes a branch comprising a first dipole with diode function D1 and a second dipole with diode function D2, which are anti-series coupled together.

[0091] exist Figure 4 In the illustrated embodiment, in each circuit 300-1, a branch including anti-series dipoles D1 and D2 is connected between terminals 301 and 302 of the circuit. In each circuit 300-1, the branch including anti-series dipoles D1 and D2 also includes a resistor R3 connected in series with the first dipole D1 between nodes 401 and 402, and a resistor R4 connected between nodes 402 and 403. Each circuit 300-1 also includes a transistor T, which has a control terminal connected to node 402 and conductive terminals connected to terminals 401 and 403, respectively. Each circuit is configured such that the voltage drop in its resistor R4 regulates the conduction of its transistor T.

[0092] According to one embodiment, such as Figure 4 As shown, in each circuit 300-1, transistor T is a P-channel MOS transistor, and the source and drain of transistor T are then coupled, preferably connected to nodes 403 and 401, respectively. Preferably, the body region of transistor T is coupled to the source of transistor T, such that the body region and the source region of transistor T are at the same potential.

[0093] In an alternative embodiment not shown, in each circuit 300-1, transistor T is replaced by a PNP bipolar transistor whose base forms the control terminal of the transistor and is connected to node 402, whose emitter is connected to node 403, and whose collector is connected to node 401.

[0094] According to one embodiment, such as Figure 4 As shown, in each circuit 300-1, dipole D2 is connected between node 401 and terminal 302 of circuit 300-1. More specifically, in this example, the cathode of dipole D2 is connected to terminal 302 of circuit 300-1. Then, in this example, node 403 is connected to terminal 301. In an alternative embodiment not shown, in each circuit 300-1, dipole D2 is connected between terminal 301 and node 403 of circuit 300-1. More specifically, the anode of dipole D2 is connected, for example, to terminal 301 of circuit 300-1, and node 401 is connected, for example, to terminal 302.

[0095] The normal operation of bridge 4-1 is similar to that of bridge 4 described above. Figure 3 This ensures normal operation. Specifically, in each circuit 300-1, when no current flows through dipoles D1 and D2 of circuit 300-1, the voltage across resistor R4 is zero, and transistor T is turned off. Therefore, no current flows between terminals 301 and 302 of circuit 300-1, nor does current flow through resistors R1 and R2.

[0096] During an overvoltage period between nodes 201 and 202, bridge 4 operates as follows. A positive overvoltage case is considered as an example. As in normal operation, circuit 300-1 associated with transistor 209 is equivalent to an open circuit between its terminals 301 and 302, and transistor 209 is turned on. Furthermore, once the voltage between nodes 202 and 201 becomes greater than the threshold voltage of circuit 300-1 associated with transistor 208, current flows through dipoles D1 and D2 and through resistors R3 and R4 of the circuit. Once the voltage drop in resistor R4 exceeds the threshold voltage of transistor T, transistor T turns on, and current flows not only through resistors R4 and R3 and dipole D1, but also through transistor T, between nodes 403 and 401. Therefore, once the voltage between nodes 202 and 201 becomes greater than the threshold voltage of circuit 300-1 associated with transistor 208, the gate potential of transistor 208 increases with the potential of node 202. Specifically, once transistor T in circuit 300-1 is turned on, the potential at the gate of transistor 208 is equal to the potential at node 202 minus the threshold voltage of transistor T, the voltage drop in resistor R3, and the voltage drop in dipoles D1 and D2 of circuit 300-1.

[0097] exist Figure 4-1In the example, the threshold voltage of each circuit 300-1 is equal to the sum of the reverse conduction threshold voltage of dipole D1 and the forward conduction threshold voltage of dipole D2. Furthermore, in each circuit 300-1, transistor T switches to the on state when the voltage between terminals 301 and 302 of the circuit exceeds the sum of the reverse conduction threshold voltage of dipole D1, the forward conduction threshold voltage of dipole D2, and the threshold voltage of transistor T.

[0098] The operation of bridge 4-1 under negative overvoltage conditions between nodes 201 and 202 can be derived from the operation under positive overvoltage conditions described above using symmetry.

[0099] The advantage of circuit 300-1 over circuit 300 is that once its transistor T is turned on, it can conduct a larger current between its terminals 301 and 302, thereby resulting in a higher potential on the gate of the associated transistor 208 or 209.

[0100] Another advantage of circuit 300-1 over circuit 300 is that the current in dipole D1 is smaller once the transistor T of the circuit is turned on. This is particularly advantageous when dipole D1 is not configured to conduct significant current and / or when the internal resistance of dipole D1 is high.

[0101] Although this is in Figure 4 Not shown, but in each circuit 300-1, a frequency compensation capacitor may be placed between nodes 401 and 403 and / or between nodes 401 and 402. Such capacitors allow circuit 300-1 to have a faster response in the event of overvoltage. However, the value of each of these capacitors is preferably chosen to be relatively low, for example, below 1 pF, to avoid interfering with the operation of bridge 4-1 in the absence of overvoltage between pads 101 and 102.

[0102] Figure 5 A portion of a device 3-2 including a rectifier bridge 4-2 according to yet another embodiment is shown in circuit form.

[0103] Equipment 3-2 is similar to Figure 4Device 3-1 is described in detail here, but only the differences between device 3-2 and device 3-1 are explained in detail. More specifically, device 3-2 differs from device 3-1 in that its voltage rectifier bridge 4-2 includes conduction circuits 300-2 instead of each circuit 300-1 of rectifier bridge 4-1. Each circuit 300-2 includes a first terminal 301, a second terminal 302, and a third terminal 303 in this embodiment. Terminal 301 of the circuit 300-2 associated with transistor 208 (209, respectively) is connected to the drain of transistor 208 (209, respectively), terminal 302 is connected to the gate of transistor 208 (209, respectively), and terminal 303 is connected to node 201 (202, respectively).

[0104] Each circuit 300-2 includes a branch comprising a first dipole with diode function D1 and a second dipole with diode function D2, which are anti-series coupled together.

[0105] In this embodiment, in each circuit 300-2, a branch including anti-series dipoles D1 and D2 is connected between terminals 301 and 303 of the circuit. Each branch including anti-series dipoles D1 and D2 in each circuit 300-2 also includes a resistor R4 connected in series with dipoles D1 and D2. Each circuit 300-2 also includes a transistor T having a control terminal connected to terminal 502 of resistor R4, a conductive terminal 503 coupled to terminal 301 of circuit 300-2, and another conductive terminal 504 coupled to terminal 302 of circuit 300-2. Each circuit 300-2 is configured such that the voltage drop in its resistor R4 regulates the conduction of its transistor T.

[0106] According to one embodiment, such as Figure 5 As shown, in each circuit 300-2, transistor T is a P-channel MOS transistor, with its source 503 coupled to terminal 301 of circuit 300-2 and its drain 504 coupled to terminal 302 of the circuit. The terminal of resistor R4 opposite to terminal 502 is then connected to terminal 503 of transistor T. Preferably, the body region of transistor T is coupled to the source of transistor T such that the body region and source region of transistor T are at the same potential. According to an alternative embodiment not shown, in each circuit 300-2, transistor T is replaced by a PNP bipolar transistor, with its base forming the control terminal of the transistor and connected to terminal 502 of resistor R4, its emitter 503 coupled to terminal 301 of circuit 300-2, and its collector 505 coupled to terminal 302 of circuit 300-2. In this variation, the terminal of resistor R4 opposite to terminal 502 is then connected to the emitter 503 of the transistor.

[0107] According to one embodiment, such as Figure 5 As shown, in each circuit 300-2, terminal 503 of transistor T is connected to terminal 301 of circuit 300-2. A dipole D2 is connected between terminal 503 of transistor T and terminal 303 of circuit 300-2, for example, with its cathode located on the side of terminal 303 of the circuit, such as connected to terminal 303. Then, circuit 300-2 further includes a dipole with diode function D3 connected in series with transistor T, between terminals 503 and 302 of transistor T, preferably between terminal 504 of transistor T and terminal 302 of circuit 300-2. The cathode of dipole D3 is connected, for example, to terminal 302 of circuit 300-2. Dipole D3 is configured to block the current between terminals 301 and 302 of circuit 300-2 when the voltage between terminal 301 of circuit 300-2 and terminal 301 of another circuit 300-2 is less than a threshold value of that circuit. In other words, dipole D3 is configured to block the current between terminals 301 and 302 of circuit 300-2 when the bridge is in normal operation, i.e., in particular when the potential on terminal 302 is greater than the potential on terminal 301 of the circuit.

[0108] The normal operation of bridge 4-2 is similar to that of bridge 4 described above. Figure 3 Normal operation of the circuit. In particular, in each circuit 300-2, no current flows through the dipoles D1, D2 and D3 of the circuit 300-2, so that no current flows between the terminal 301 of the circuit 300-2 and each of the terminals 302 and 303 of the circuit.

[0109] During an overvoltage period between nodes 201 and 202, bridge 4-2 operates as follows. A positive overvoltage case is considered as an example. As in normal operation, circuit 300-2 associated with transistor 209 is equivalent to an open circuit between its terminals 301 and 302, and transistor 209 is turned on. Furthermore, once the voltage between nodes 202 and 201 becomes greater than the threshold voltage of circuit 300-2 associated with transistor 208, current flows through circuit dipoles D1 and D2, and thus through resistor R4. Once the voltage drop in resistor R4 exceeds the threshold voltage of transistor T, transistor T switches to the on state, and current flows between terminals 301 and 302 of the circuit, and thus through resistor R4. Therefore, the gate potential of transistor 208 increases with the potential of node 202. In other words, the potential at the gate of transistor 208 is then equal to the potential of node 202 minus the voltage drop between terminals 503 and 504 of transistor T and the voltage drop in dipole D3. Figure 5 In the example, the threshold voltage of each circuit 300 is equal to the sum of the reverse conduction threshold voltage of dipole D1, the forward conduction threshold voltage of dipole D2, and the threshold voltage of transistor T.

[0110] As an example, consider the case where dipoles D2 and D3 have a forward conduction threshold of 0.6V and dipole D1 has a reverse conduction threshold of 5V. In this case, when current flows from terminal 301 to terminal 302 due to the voltage between terminals 301 and 303 (relative to terminal 303) being greater than the threshold of circuit 300-2, the voltage at the gate of transistor T can be at most equal to 5.6V, which is the sum of the forward conduction threshold of dipole D2 and the reverse conduction threshold of dipole D1. Resistor R4 then bears the difference between the voltage at the gate of transistor T and the voltage at terminal 301. Once transistor T is turned on, the voltage drop between terminals 301 and 302 is equal to the forward conduction threshold of dipole D3, ignoring the voltage drop between the conducting ends of transistor T. Therefore, the voltage at terminal 302 is then equal to the voltage at node 202 minus 0.6V in D3, and when the voltage at node 202 is 7V, the voltage at terminal 302 can be equal to 6.4V. Figure 4 In this numerical example, the voltage at terminal 302 of the circuit is at most equal to the voltage at node 202 minus the sum of the forward conduction threshold of D2, the reverse conduction threshold of D1, and the conduction threshold of transistor T, for example, equal to 0.7V. This results in the voltage at terminal 302 being equal to 0.7V, and is lower than... Figure 5 The situation is much smaller.

[0111] The operation of bridge 4-2 under negative overvoltage conditions between nodes 201 and 202 can be derived from the operation under positive overvoltage conditions described above using symmetry.

[0112] In an alternative embodiment not shown, in each circuit 300-2, dipole D2 is connected between terminal 301 of circuit 300-2 and terminal 503 of transistor T. For example, the anode of dipole D2 is connected to terminal 301. In this variant, terminal 504 of transistor T is connected to terminal 302 of circuit 300-2. Furthermore, in this variant, dipole D3 can be omitted, its current blocking function being ensured by dipole D2. However, in this variant, the connections of the body region of transistor T are modified to prevent the drain body diode of transistor T from forward conducting during normal operation when the potential of terminal 302 is greater than the potential of terminal 301, and potentially turning on the NPN bipolar transistor of transistor T, whose emitter corresponds to the drain of transistor T, whose base corresponds to the N-type well in which transistor T is formed, and whose collector corresponds to the P-type substrate in which the N-type well is formed. For example, transistor T can then be associated with two MOS transistors cross-connected between the source and drain of transistor T to ensure that the N-well of transistor T is at the lower of the two source and drain potentials of transistor T.

[0113] Those skilled in the art can describe the operation of bridge 4-2 according to the above operation.

[0114] Compared to circuit 300-1, the advantages of the above-described embodiments and variations of circuit 300-2 are that, once its transistor T is turned on, it can reduce the voltage drop between its terminals 301 and 302. Therefore, the potential at the gate of its associated transistor 208 or 209 is higher.

[0115] Although this is in Figure 5 Not shown, but the frequency compensation capacitor may be connected in parallel with dipole D1 and / or the frequency compensation capacitor may be connected in parallel with transistor T. These capacitors allow for a faster response of circuit 300-2 in the event of overvoltage. However, the value of each of these capacitors is preferably chosen to be relatively low, for example, below 1pF, to avoid interfering with the operation of bridge 4-2 in the absence of overvoltage between pads 101 and 102.

[0116] Figure 6 A portion of a device 3-3 including a rectifier bridge 4-3 according to yet another embodiment is shown in circuit form.

[0117] Equipment 3-3 is similar to Figure 4 Device 3-1 is described in detail here, but only the differences between Device 3-3 and Device 3-1 are explained in detail. More specifically, Device 3-3 differs from Device 3-1 in that its voltage rectifier bridge 4-3 includes conduction circuit 300-3 instead of each circuit 300-1 of rectifier bridge 4-1. Each circuit 300-3 includes a first terminal 301 and a second terminal 302. Terminal 301 of the circuit 300-3 associated with transistor 208 (209, respectively) is connected to the drain of transistor 208 (209, respectively), and its terminal 302 is connected to the gate of transistor 208 (209, respectively).

[0118] Each circuit 300-3 includes a branch comprising a first dipole with diode function D1 and a second dipole with diode function D2, which are anti-series coupled together.

[0119] In this embodiment, in each circuit 300-3, a branch including anti-series dipoles D1 and D2 is connected between terminals 301 and 302 of the circuit. Each branch including anti-series dipoles D1 and D2 in each circuit 300-3 also includes a resistor R3 for the first dipole D1 connected in series between nodes 601 and 602, and a resistor R4 connected between nodes 602 and 603. Each circuit 300-3 also includes a transistor Tb, which has a control terminal connected to node 602 and conductive terminals connected to nodes 601 and 603, respectively. Each circuit is configured such that the voltage drop in its resistor R4 regulates the conduction of its transistor Tb.

[0120] According to one embodiment, such as Figure 6 As shown, in each circuit 300-3, transistor Tb is an NPN bipolar transistor, and the emitter and collector of transistor Tb are coupled (preferably connected) to nodes 603 and 601, respectively. In an alternative embodiment not shown, in each circuit 300-3, the bipolar transistor Tb is replaced by an N-channel MOS transistor, the gate of which forms a control terminal connected to node 602, the source connected to node 603, and the drain connected to node 601. Preferably, the body region of the MOS transistor is then coupled to the source of the transistor such that the body region and the source region of the transistor are at the same potential.

[0121] According to one embodiment, such as Figure 6 As shown, in each circuit 300-3, dipole D2 is connected between node 603 and terminal 302 of circuit 300-2, and the cathode of dipole D2 is connected, for example, to terminal 302 of circuit 300-1. In an alternative embodiment not shown, in each circuit 300-2, dipole D2 is connected between terminal 301 of circuit 300-3 and node 601, and the anode of dipole D2 is connected, for example, to terminal 301 of circuit 300-3.

[0122] The normal operation of bridge 4-3 is similar to that of bridge 4 described above. Figure 3 This ensures normal operation. Specifically, in each circuit 300-3, when no current flows through dipoles D1 and D2 of circuit 300-3, the voltage across resistor R4 is zero, and transistor Tb is cut off. Therefore, no current flows between terminals 301 and 302 of circuit 300-3, and no current flows through resistors R1 and R2.

[0123] During an overvoltage event between nodes 201 and 202, bridge 4-3 operates as follows. A positive overvoltage case is considered as an example. As in normal operation, circuit 300-3 associated with transistor 209 is equivalent to an open circuit between its terminals 301 and 302, and transistor 209 is turned on. Furthermore, once the voltage between nodes 202 and 201 becomes greater than the threshold voltage of circuit 300-3 associated with transistor 208, current flows through dipoles D1 and D2 of the circuit and through resistor R4. Once the voltage drop in resistor R4 exceeds the threshold voltage of transistor Tb, current flows not only through resistors R3 and R4 and dipole D1, but also through transistor Tb, between nodes 601 and 603. Therefore, once the voltage between nodes 202 and 201 becomes greater than the threshold voltage of circuit 300-3, the gate potential of transistor 208 increases with the potential of node 202. Specifically, once transistor Tb in circuit 300-3 is turned on, the potential at the gate of transistor 208 is equal to the potential at node 202 minus the threshold voltage of transistor Tb, the voltage drop in resistor R3, and the voltage drops in dipoles D1 and D2 of circuit 300-3.

[0124] exist Figure 6 In the example, the threshold of each circuit 300-3 is equal to the sum of the reverse conduction threshold of dipole D1 and the forward conduction threshold of dipole D2. Furthermore, once the voltage between terminals 301 and 302 of the circuit exceeds the sum of the reverse conduction threshold of dipole D1, the forward conduction threshold of dipole D2, and the threshold of transistor Tb, transistor Tb switches to the on state.

[0125] The operation of bridge 4-3 under negative overvoltage conditions between nodes 201 and 202 can be derived from the operation under positive overvoltage conditions described above using symmetry.

[0126] The advantage of circuit 300-3 over circuit 300 is that once its transistor Tb is turned on, circuit 300-3 is able to conduct a more significant current between its terminals 301 and 302, thereby resulting in a higher potential on the gate of the associated transistor 208 or 209.

[0127] Although this is in Figure 6 Not shown, but in each circuit 300-3, a frequency compensation capacitor may be placed between nodes 601 and 603 and / or between nodes 601 and 602. Such capacitors allow circuit 300-3 to respond more quickly in the event of overvoltage. However, the value of each of these capacitors is preferably chosen to be relatively low, for example, below 1 pF, to avoid interfering with the operation of bridge 4-3 in the absence of overvoltage between pads 101 and 102.

[0128] According to one embodiment, the dipole D1 of the circuits 300-1, 300-2 and 300-3 described above is implemented by a single Zener diode.

[0129] According to another embodiment, the dipole D1 of the circuits 300, 300-1, 300-2 and 300-3 is implemented by means of a plurality of Zener diodes connected in parallel, which reduces the internal resistance of the dipole D1 and thus reduces the voltage drop between its terminals when current flows through the dipole D1.

[0130] According to another embodiment, the dipole D1 of the circuits 300, 300-1, 300-2, and 300-3 is implemented by multiple MOS transistors connected in series. Each MOS transistor is an assembled diode, i.e., its drain and gate are connected together, with the transistor drain located on the cathode side of the dipole. This allows for a reduction or finer adjustment of the reverse conduction threshold of the dipole D1 at the cost of increasing its internal resistance, thereby adjusting the reverse conduction thresholds of circuits 300, 300-1, 300-2, and 300-3. The dipole D1 of circuits 300, 300-1, 300-2, and 300-3, as well as the possible dipole D3 of circuit 300-2, are all implemented by diodes or MOS transistors assembled as diodes.

[0131] To protect device 1 from overvoltage, instead of providing circuits 300, 300-1, 300-2, and 300-3, it could be designed with overvoltage protection between each of pads 101 and 102 and node 210 at ground potential. However, providing such protection would result in devices with a larger surface area than devices 3, 3-1, 3-2, and 3-3. Furthermore, this protection would introduce stray capacitance and resistance on each pad 101 and 102, which could interfere with the operation of the rectifier bridge in the absence of overvoltage.

[0132] According to embodiments where devices 3, 3-1, 3-2, or 3-3 include an inverting modulation MOS transistor connected between its pads 101 and 102, the inverting modulation MOS transistor can be provided to two circuits 300, 300-1, 300-2, or 300-3 respectively associated with the inverting modulation transistor to turn on the inverting modulation transistor when an overvoltage occurs on one or the other of pads 101 and 102. Then, terminal 301 of the first circuit of the two circuits 300, 300-1, 300-2, or 300-3 is connected to pad 102, and its possible terminal 303 is connected to pad 101, while its terminal 302 is connected to the gate of the inverting modulation transistor and coupled to pad 101 via a resistor. Then, terminal 301 of the second circuit of the two circuits is connected to pad 101, and its possible terminal 303 is connected to pad 102, while its terminal 302 is connected to the gate of the inverting modulation transistor and coupled to pad 102 via another resistor.

[0133] Although this is not claimed in this document, as mentioned above, the two conduction circuits can be associated with the inverting modulation transistor without transistors 208 and 209 being associated with the conduction circuits individually.

[0134] According to embodiments not shown, the conduction circuits of the same devices 3, 3-1, 3-2, or 3-3 may differ from each other, including when these circuits are associated with the inverting modulation transistor. For example, circuit 300 of bridge 3 associated with transistor 208 may be replaced by circuits 300-1, 300-2, or 300-3.

[0135] According to one embodiment, the pads 101 and 102 of rectifier bridges 4, 4-1, 4-2 or 4-3 and devices 3, 3-1, 3-2 or 3-3 belong to the same integrated circuit, and the conductive antenna winding is preferably located outside the integrated circuit.

[0136] Although wireless communication devices 3, 3-1, 3-2, and 3-3 have been described herein, such as NFC (Near Field Communication) devices or devices according to ISO standards 14443 or 15693, rectifier bridges 4, 4-1, 4-2, and 4-3 may be implemented in other devices to protect the circuitry of these other devices from possible overvoltages, such as overvoltages caused by electrostatic discharge on one or the other of two pads having corresponding nodes 201 and 202 of the rectifier bridge coupled thereto.

[0137] Furthermore, those skilled in the art can apply the above disclosure to transistors 208 and 209 when they have a P-channel, for example, by inverting all the N-type and P-type voltage values, for example, by replacing each N-channel MOS transistor with a P-channel MOS transistor (each an N-channel MOS transistor), by replacing each NPN transistor (each a PNP transistor) with a PNP transistor (each an NPN transistor), by replacing the P-substrate coupled to the circuit at the lowest potential with the N-substrate coupled to the circuit at the highest potential, and so on. In this case, the threshold of the conducting circuit is negative and equal in absolute value to Figures 2 to 6 The threshold of the conducting circuit. Then, if the voltage between terminal 301 of this circuit and terminal 301 of another conducting circuit has the same sign as the threshold and an absolute value greater than the absolute value of the threshold, then the voltage is said to be greater than the threshold of this circuit. In other words, regardless of whether transistors 208 and 209 have N-channel or P-channel, the conducting circuit is configured to electrically couple its terminals 301 and 302 when the voltage between terminal 301 of this circuit and terminal 301 of another circuit has the same sign as the circuit threshold and an absolute value greater than the absolute value of the threshold, and to isolate its terminals 301 and 302 when the voltage between terminal 301 of this circuit and terminal 301 of another conducting circuit has an absolute value less than the absolute value of the threshold and when the voltage has the opposite sign to the circuit threshold.

[0138] Various embodiments and variations have been described. Those skilled in the art will understand that certain features of these embodiments can be combined, and other variations will readily occur to them.

[0139] Finally, based on the functional indications given above, the actual implementation of the described embodiments and variations is within the capabilities of those skilled in the art. In particular, those skilled in the art can select the resistor values, the values ​​of possible frequency compensation capacitors, the forward conduction threshold of dipole D2, the forward conduction threshold of possible dipole D3, and / or the reverse conduction threshold of dipole D1, according to the target application, i.e., according to the maximum voltage that can exist between nodes 201 and 202 in normal operation (without overvoltage) and / or the maximum amplitude of the overvoltage that can occur between nodes 201 and 202. For example, the values ​​of resistors R1 and R2 should be low enough to avoid interfering with the bridge in normal operation by introducing an R*C type propagation delay (C is the capacitance of the gates of transistors 208 and 209), for example, less than 10 kΩ, and high enough so that the conduction circuit can increase the voltage on the gates of transistors 208 and 209, for example, greater than 100 Ω, with resistors R1 and R2 each having a value of approximately 1 kΩ, for example, equal to 1 kΩ.

[0140] Such changes, modifications, and improvements are intended to be part of this disclosure and are intended to be within the spirit and scope of the invention. Therefore, the above description is exemplary only and not restrictive. The invention is limited only by the limitations defined in the appended claims and their equivalents.

Claims

1. An electronic device comprising a rectifier bridge, the rectifier bridge comprising: The first branch connects between the first and second input nodes of the bridge and includes the third output node of the bridge; The second branch includes a first metal-oxide-semiconductor (MOS) transistor and a second MOS transistor connected in series between the first input node and the second input node, wherein the sources of the first MOS transistor and the second MOS transistor are coupled to the fourth output node of the bridge. A first resistor is connected between the gate of the first metal-oxide-semiconductor transistor and the second input node; A second resistor is connected between the gate of the second metal-oxide-semiconductor transistor and the first input node; as well as For each of the first metal-oxide-semiconductor transistor and the second metal-oxide-semiconductor transistor, the circuit associated with the transistor includes: a first terminal connected to the drain of the transistor; and a second terminal connected to the gate of the transistor, wherein the circuit is configured to electrically couple the first terminal and the second terminal of the circuit when the absolute value of the voltage between the first terminal of the circuit and the first terminal of another circuit is greater than or equal to the absolute value of a threshold of the circuit and the voltage has the same sign as the threshold.

2. The device of claim 1, wherein each circuit is further configured to electrically isolate the first and second terminals of the circuit when the absolute value of the voltage between the first terminal of the circuit and the first terminal of the other circuit is less than the absolute value of the threshold of the circuit, and when the voltage has a sign opposite to the sign of the threshold of the circuit.

3. The device of claim 1, wherein the first branch of the bridge comprises: The third MOS transistor and the fourth MOS transistor are connected in series between the first input node and the second input node, and each is assembled into a diode, and the source of the third MOS transistor and the fourth MOS transistor is connected to the third output node.

4. The device according to claim 3, wherein the first metal-oxide-semiconductor transistor, the second metal-oxide-semiconductor transistor, the third MOS transistor and the fourth MOS transistor have the same N-channel or P-channel.

5. The device of claim 1, wherein each circuit includes a branch comprising a first dipole having a first diode function and a second dipole having a second diode function, both anti-series coupled, one end of the branch being connected to the first terminal of the circuit, and the other end of the branch being coupled to the first terminal of the other circuit.

6. The device according to claim 5, wherein, In each circuit, the first dipole and the second dipole are configured to: block current when the absolute value of the voltage between the first terminal of the circuit and the first terminal of the other circuit is less than the absolute value of the threshold of the circuit and when the voltage has a sign opposite to the sign of the threshold of the circuit, and conduct current when the absolute value of the voltage between the first terminal of the circuit and the first terminal of the other circuit is greater than or equal to the absolute value of the threshold of the circuit and when the voltage has the same sign as the threshold.

7. The device of claim 6, wherein each circuit is configured such that the conduction of the current in the first dipole of the circuit causes electrical coupling between the first terminal and the second terminal of the circuit.

8. The device according to claim 5, wherein, In at least one of the circuits, the other end of the branch of the circuit is connected to the second terminal of the circuit.

9. The device according to claim 8, wherein, In the at least one circuit in the circuit, the branch of the circuit includes: The fifth, sixth, and seventh nodes; A third resistor is connected in series with the first dipole between the fifth node and the sixth node; and A fourth resistor is connected between the sixth node and the seventh node. Each circuit also includes a transistor having a control terminal connected to the sixth node and conductive terminals connected to the fifth and seventh nodes respectively, the voltage drop in the fourth resistor regulating the conduction of the transistor.

10. The device according to claim 9, wherein, In at least one circuit in the circuit: The second dipole is connected between the seventh node and the second terminal of the circuit, and the fifth node is connected to the first terminal of the circuit; or The second dipole is connected between the first terminal and the seventh node of the circuit, and the fifth node is connected to the second terminal of the circuit; or The second dipole is connected between the fifth node and the second terminal of the circuit, and the seventh node is connected to the first terminal of the circuit.

11. The device according to claim 5, wherein, In at least one of the circuits, the other end of the branch of the circuit is connected to a third terminal of the circuit, and the third terminal of the circuit is connected to the first terminal of the other circuit.

12. The device according to claim 11, wherein, In the at least one circuit of the circuit, the branch includes a third resistor connected in series with the first dipole and the second dipole, each circuit also includes a transistor having a control terminal connected to a terminal of the third resistor, a first conductive terminal coupled to the first terminal of the circuit, and a second conductive terminal coupled to the second terminal of the circuit, wherein a voltage drop in the third resistor regulates the conduction of the transistor.

13. The device according to claim 12, wherein, In at least one circuit of the circuit, the second dipole is connected between the first terminal of the circuit and the first conductive terminal of the transistor, and the second conductive terminal of the transistor is connected to the second terminal of the circuit.

14. The device of claim 12, wherein at least one circuit in the circuit further comprises a third dipole having a diode function, the third dipole being connected in series with the transistor of the circuit, the transistor of the circuit being located between the first terminal and the second terminal of the circuit, the third dipole being connected to the second terminal of the circuit, and the branch of the circuit being connected between the first terminal and the third terminal of the circuit.

15. The device of claim 5, wherein the first dipole is a Zener diode, a plurality of Zener diodes connected in parallel, or a plurality of MOS transistors configured as diodes connected in series.

16. An integrated circuit IC, comprising: First input pad and second input pad; as well as The rectifier bridge includes: The first branch connects between the first and second input pads of the bridge and includes the third output node of the bridge; The second branch includes a first metal-oxide-semiconductor (MOS) transistor and a second MOS transistor connected in series between the first input pad and the second input pad, wherein the sources of the first MOS transistor and the second MOS transistor are coupled to the fourth output node of the bridge. A first resistor is connected between the gate of the first metal-oxide-semiconductor transistor and the second input pad; A second resistor is connected between the gate of the second metal-oxide-semiconductor transistor and the first input pad; and The circuit, for each of the first metal-oxide-semiconductor transistor and the second metal-oxide-semiconductor transistor, includes: a first terminal connected to the drain of the transistor; and a second terminal connected to the gate of the transistor, wherein the circuit is configured to electrically couple the first terminal and the second terminal of the circuit when the absolute value of a voltage between the first terminal of the circuit and the first terminal of another circuit is greater than or equal to the absolute value of a threshold of the circuit, and the voltage has the same sign as the threshold.

17. The IC of claim 16, wherein each circuit is further configured to electrically isolate the first and second terminals of the circuit when the absolute value of the voltage between the first terminal of the circuit and the first terminal of the other circuit is less than the absolute value of the threshold of the circuit, and when the voltage has a sign opposite to the sign of the threshold of the circuit.

18. The IC of claim 16, wherein the first branch of the bridge comprises: The third MOS transistor and the fourth MOS transistor are connected in series between the first input pad and the second input pad, and each is assembled into a diode, and the source of the third MOS transistor and the fourth MOS transistor are connected to the third output node.

19. The IC of claim 16, wherein each circuit includes a branch, the branch comprising: A first dipole with a first diode function and a second dipole with a second diode function are anti-series coupled, one end of the branch is connected to the first terminal of the circuit, and the other end of the branch is coupled to the first terminal of the other circuit.

20. The IC of claim 16, wherein the first input pad and the second input pad are configured to be coupled to corresponding ends of the conductive winding of the antenna.

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