Pseudo bidirectional electrostatic discharge protection device

Abstract

The utility model relates to a pseudo bidirectional electrostatic discharge protection device. A pseudo bidirectional electrostatic discharge protection device includes first and second diodes respectively coupling first and second terminals to a same intermediate node of the device. A third diode couples the intermediate node to a third terminal to which a reference potential is applied. The capacitance of the third diode is larger than the capacitance of the first diode and the second diode. The first capacitance element and the second capacitance element are connected in parallel with the first diode and the second diode, respectively.

Description

[0001] Priority claim

[0002] This application claims the benefit of priority of French Patent Application No. 2302482, filed on March 17, 2023, the contents of which are hereby incorporated by reference in their entirety to the maximum extent permitted by law. Technical Field

[0003] The present disclosure relates generally to electronic devices, and in particular, to electrostatic discharge protection devices. Background Art

[0004] Electrostatic discharge may cause harmful effects in an integrated circuit or electronic component subjected to the electrostatic discharge, which may cause all or part of its components to deteriorate irreversibly. As a result, the integrated circuit or electronic component may suffer major failures or even fail to function completely due to electrostatic discharge. Sometimes it may be necessary to replace a defective circuit or component, which adversely affects the reliability of the electronic device in which the circuit or component is integrated.

[0005] In order to avoid the harmful consequences of electrostatic discharge, integrated circuits and electronic components may include protection devices. However, existing electrostatic discharge protection devices face various disadvantages. Specifically, the presence of the protection device may hinder the operation of other circuits or components next to the device.

[0006] There is a need to improve existing electrostatic discharge protection devices. In particular, there is a need to reduce interference caused by the presence of electrostatic discharge protection devices in electronic devices. Utility Model Content

[0007] One aspect of the present disclosure provides a pseudo-bidirectional electrostatic discharge protection device, which includes: a first diode, which couples a first terminal to an intermediate node; a second diode, which couples a second terminal to the intermediate node; and a third diode, which couples the intermediate node to a third terminal to which a reference potential is applied; wherein the capacitance of the third diode is greater than the capacitance of the first diode and greater than the capacitance of the second diode; a first capacitance element, which is connected in parallel with the first diode; and a second capacitance element, which is connected in parallel with the second diode.

[0008] According to at least one embodiment, the first diode includes an anode electrode and a cathode electrode connected to the intermediate node and the first terminal, respectively; and the second diode includes an anode electrode and a cathode electrode connected to the intermediate node and the second terminal, respectively.

[0009] In accordance with at least one embodiment, the third diode includes an anode electrode and a cathode electrode connected to the intermediate node and the third terminal, respectively.

[0010] In accordance with at least one embodiment, the first capacitive element and the second capacitive element are capacitors.

[0011] According to at least one embodiment, the device has a monolithic structure.

[0012] In accordance with at least one embodiment, the first and second capacitive elements are capacitors, and wherein the first and second capacitive elements are metal-insulator-metal MIM capacitors formed as a stack of conductive layers of the monolithic structure.

[0013] According to at least one embodiment, the apparatus further includes: a third capacitive element coupling the first terminal to the third terminal; and a fourth capacitive element coupling the second terminal to the third terminal.

[0014] According to at least one embodiment, the apparatus further includes: a first resistance element coupling the first terminal to a fourth terminal; and a second resistance element coupling the second terminal to a fifth terminal.

[0015] According to at least one embodiment, the third capacitive element and the fourth capacitive element each have a capacitance equal to approximately 55 pF; and the first resistive element and the second resistive element each have a resistance equal to approximately 50Ω.

[0016] In accordance with at least one embodiment, the first diode, the second diode, and the third diode are Zener diodes.

[0017] In accordance with at least one embodiment, the first diode, the second diode, and the third diode are transient voltage suppression diodes.

[0018] In accordance with at least one embodiment, the first capacitive element and the second capacitive element have substantially the same capacitance as each other.

[0019] In accordance with at least one embodiment, the first capacitive element and the second capacitive element each have a capacitance equal to approximately 10 pF.

[0020] In accordance with at least one embodiment, a capacitance of the third diode is at least twice as large as a capacitance of the first diode and the second diode.

[0021] In accordance with at least one embodiment, a capacitance of the third diode is at least five times greater than a capacitance of the first diode and the second diode.

[0022] In accordance with at least one embodiment, a capacitance of the third diode is approximately ten times greater than a capacitance of the first diode and the second diode.

[0023] According to at least one embodiment, the first diode and the second diode each have a capacitance equal to approximately 4.5 pF; and the third diode has a capacitance equal to approximately 38 pF.

[0024] In accordance with at least one embodiment, the first terminal and the second terminal are input terminals and / or output terminals of an integrated circuit.

[0025] According to at least one embodiment, the intermediate node corresponds to a semiconductor substrate in which and on top of which the device is formed.

[0026] Another aspect of the present disclosure provides a pseudo-bidirectional electrostatic discharge protection device, the device comprising: a first diode, the first diode having a first capacitance, the anode of the first diode being connected to an intermediate node and the cathode being connected to a first terminal; a first capacitor, the first capacitor having a first node connected to the intermediate node and a second node connected to the first terminal; a second diode, the second diode having a second capacitance, the anode of the first diode being connected to the intermediate node and the cathode being connected to the second terminal; a second capacitor, the second capacitor having a first node connected to the intermediate node and a second node connected to the second terminal; a third diode, the third diode having a third capacitance, the anode of the third diode being connected to the intermediate node and the cathode being connected to a third terminal; a third capacitor, the third capacitor having a first node connected to the first terminal and a second node connected to the third terminal; and a fourth capacitor, the fourth capacitor having a first node connected to the second terminal and a second node connected to the third terminal; wherein the third capacitance is greater than the first capacitance and the second capacitance.

[0027] In accordance with at least one embodiment, the first diode, the second diode, and the third diode are Zener diodes.

[0028] In accordance with at least one embodiment, the first diode, the second diode, and the third diode are transient voltage suppression diodes.

[0029] In accordance with at least one embodiment, the first terminal and the second terminal are input terminals and / or output terminals of an integrated circuit.

[0030] According to at least one embodiment, the intermediate node corresponds to a semiconductor substrate in which and on top of which the device is formed.

[0031] One embodiment provides a pseudo-bidirectional electrostatic discharge protection device, which includes: a first diode and a second diode, wherein the first diode and the second diode respectively couple a first terminal and a second terminal to the same intermediate node of the device; and a third diode, wherein the third diode couples the intermediate node to a third terminal to which a reference potential is applied; wherein the capacitance of the third diode is greater than the capacitance of the first diode and the second diode, and the device also includes a first capacitance element and a second capacitance element respectively connected in parallel with the first diode and the second diode.

[0032] According to one embodiment: the first diode comprises an anode electrode and a cathode electrode connected to the intermediate node and the first terminal, respectively; and the second diode comprises an anode electrode and a cathode electrode connected to the intermediate node and the second terminal, respectively.

[0033] According to an embodiment, the third diode comprises an anode electrode and a cathode electrode connected to the intermediate node and the third terminal, respectively.

[0034] According to an embodiment, the first capacitive element and the second capacitive element are capacitors.

[0035] According to one embodiment, the device has a monolithic structure.

[0036] According to one embodiment, the first capacitive element and the second capacitive element are MIM capacitors.

[0037] According to one embodiment, the device also includes: a third capacitor element and a fourth capacitor element, wherein the third capacitor element and the fourth capacitor element are far away from the first capacitor element and the second capacitor element, and couple the first terminal and the second terminal to the third terminal respectively; and a first resistor element and a second resistor element, wherein the first resistor element and the second resistor element couple the first terminal and the second terminal to a fourth terminal and a fifth terminal respectively.

[0038] According to one embodiment: the third capacitive element and the fourth capacitive element each have a capacitance equal to substantially 55 pF; and the first resistive element and the second resistive element each have a resistance equal to substantially 50Ω.

[0039] According to one embodiment, the first diode, the second diode and the third diode are Zener diodes or transient voltage suppression diodes.

[0040] According to one embodiment, the first capacitive element and the second capacitive element have substantially the same capacitance as each other.

[0041] According to one embodiment, the first capacitive element and the second capacitive element each have a capacitance equal to approximately 10 pF.

[0042] According to an embodiment, the capacitance of the third diode is at least twice, preferably at least five times, more preferably at least ten times, the capacitance of the first diode and the second diode.

[0043] According to one embodiment: the first diode and the second diode each have a capacitance equal to substantially 4.5 pF; and the third diode has a capacitance equal to substantially 38 pF.

[0044] According to an embodiment, the first terminal and the second terminal are input terminals and / or output terminals of an integrated circuit.

[0045] According to one embodiment, the intermediate node corresponds to a semiconductor substrate within and on top of which the device is formed. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The above and other features and advantages of the present invention will be discussed in detail in the following non-limiting description of specific embodiments in conjunction with the accompanying drawings, in which:

[0047] Figure 1 is a circuit diagram illustrating an example of an electrostatic discharge protection device;

[0048] Figure 2 is a circuit diagram illustrating an example of an electrostatic discharge protection device according to one embodiment; and

[0049] Figure 3 is a circuit diagram illustrating another example of an electrostatic discharge protection device according to one embodiment. DETAILED DESCRIPTION

[0050] In the various drawings, similar features have been designated by similar reference symbols. In particular, common structural and / or functional features between the various embodiments may have the same reference symbols and may have the same structure, dimensions, and material properties.

[0051] For the sake of clarity, only the steps and elements useful for understanding the embodiments described herein are illustrated and described in detail. In particular, components or integrated circuits that may be protected from electrostatic discharge by the apparatus of the present disclosure will not be described in detail, and the embodiments described are compatible with components or integrated circuits that can be protected from electrostatic discharge in general.

[0052] Unless otherwise indicated, when referring to two elements being connected together, this means a direct connection without any intermediate elements except conductors, and when referring to two elements being coupled together, this means the two elements may be connected or they may be coupled via one or more other elements.

[0053] In the following description, when referring to terms such as "front", "back", "top", "bottom", "left", "right", or terms such as "above", "below", "upper", "lower", or terms such as "horizontal", "vertical", or qualitative directions, it refers to the orientation in the drawing unless otherwise specified.

[0054] Unless otherwise specified, the expressions "about", "substantially", "substantially" and "approximately" mean plus or minus 10%, preferably plus or minus 5%.

[0055] Figure 1 is a circuit diagram illustrating an example of the electrostatic discharge protection device 100 .

[0056] In the example shown, the device 100 comprises a plurality of diodes 101-1, 101-2, ..., 101-n, respectively coupling terminals 103-1, 103-2, ..., 103-n to the same intermediate node 105. More precisely, in Figure 1 In the example illustrated in , each diode 101 - 1 , 101 - 2 , . . . , 101 - n includes an anode electrode or anode terminal connected to the intermediate node 105 , and a cathode electrode or cathode terminal connected to the corresponding terminal 103 - 1 , 103 - 2 , . . . , 103 - n .

[0057] Terminals 103-1, 103-2, ..., 103-n are, for example, input terminals, output terminals or input-output terminals of an integrated circuit or electronic component to be protected from electrostatic discharge. Each terminal 103-1, 103-2, ..., 103-n is, for example, configured to receive or send a digital signal or an analog signal, for example, an analog signal with a frequency less than 10 MHz or 20 MHz. As an example, terminals 103-1, 103-2, ..., 103-n withstand a potential of about 3.3 V, about 5 V or about 15 V in nominal operation.

[0058] Typically, the device 100 comprises n branches, each branch comprising a terminal 103 coupled to a node 105 via a diode 101, where n is an integer greater than or equal to 2. For example, the number n is equal to the number of external terminals 103 of the integrated circuit to be protected from electrostatic discharge.

[0059] In the example shown, the electrostatic discharge protection device 100 further comprises a further diode 107 coupling the intermediate node 105 to a further terminal 109 (eg ground) to which a reference potential is applied. More precisely, in Figure 1 In the example illustrated in , the diode 107 comprises an anode electrode or anode terminal connected to the intermediate node 105 , and a cathode electrode or cathode terminal connected to a terminal 109 to which a reference potential is applied.

[0060] The electrostatic discharge protection device 100 has a so-called “pseudo-bidirectional” architecture. This is manifested by the fact that the anodes of the diodes 101-1, 101-2, ..., 101-n connected to the terminals 103-1, 103-2, ..., 103-n are connected to the same node 105, and a separate diode 107 couples the anodes of the diodes 101-1, 101-2, ..., 101-n to a terminal 109 to which a reference potential is applied.

[0061] The capacitance of the diode 107 of the device 100 is, for example, at least twice, for example, at least five times, for example, approximately ten times, the capacitance of each diode 101-1, 101-2, ..., 101-n. This makes it possible to reduce the crosstalk phenomenon between the terminals 103-1, 103-2, ..., 103-n. The capacitance of each diode 101-1, 101-2, ..., 101-n is, for example, about several pico-farads, and the capacitance of the diode 107 is, for example, about several tens of pico-farads. The diodes 101-1, 101-2, ..., 101-n of the device 100 have capacitances that are substantially equal to each other, for example, within manufacturing deviations. As an example, each diode 101-1, 101-2, ..., 101-n has a capacitance equal to approximately 4.5 pF, and the diode 107 has a capacitance equal to approximately 38 pF.

[0062] In the illustrated example, the diodes 101-1, 101-2, ..., 101-n and 107 of the device 100 are Zener diodes. However, this example is not limiting, and as a variation, each diode 101-1, 101-2, ..., 101-n, 107 of the device 100 may be a transient voltage suppression (TVS) diode.

[0063] In the case of electrostatic discharge, a positive or negative overvoltage may occur between one of the terminals 103-1, 103-2, ..., 103-n and the terminal 109 to which the reference potential is applied. For example, in the case where each terminal 103-1, 103-2, ..., 103-n is configured to be biased by a nominal voltage equal to approximately 3.3 V, the positive overvoltage may correspond to a voltage of approximately +10 V applied between the terminals 103-1, 103-2, ..., 103-n and the terminal 109, and the negative overvoltage may correspond to a voltage of approximately -10 V applied between the terminals 103-1, 103-2, ..., 103-n and the terminal 109.

[0064] In the case of a positive overvoltage between one of the terminals 103-1, 103-2, ..., 103-n of the device 100 and the terminal 109, the diodes 101-1, 101-2, ..., 101-n connected to the terminal are reverse biased by a voltage greater than their breakdown voltage or avalanche voltage, and the diode 107 is forward biased by a voltage greater than its threshold voltage. Then, the diodes 103-1, 103-2, ..., 103-n conduct reverse current, and the diode 107 conducts direct current. Therefore, the current obtained by electrostatic discharge flows out from the terminals 103-1, 103-2, ..., 103-n to the terminal 109.

[0065] In the case of a negative overvoltage between one of the terminals 103-1, 103-2, ..., 103-n of the device 100 and the terminal 109, the diodes 101-1, 101-2, ..., 101-n connected to the terminal are forward biased by a voltage greater than their threshold voltage, and the diode 107 is reverse biased by a voltage greater than its breakdown voltage or avalanche voltage. Then, the diodes 101-1, 101-2, ..., 101-n conduct direct current, and the diode 107 conducts reverse current. Therefore, the current obtained by electrostatic discharge flows from the terminal 109 to the terminals 103-1, 103-2, ..., 103-n.

[0066] A disadvantage of the electrostatic discharge protection device 100 is the fact that its presence generates harmonics (particularly second and third order harmonics) at the terminals 103 - 1 , 103 - 2 , . . . , 103 - n .

[0067] In order to reduce the generation of harmonics, a solution may include replacing the pseudo-bidirectional device 100 with an electrostatic discharge protection device having a fully bidirectional structure. In such a device, the anodes of n diodes 101-1, 101-2, ..., 101-n are, for example, respectively connected to the anodes of other n diodes, and the cathodes of the other n diodes are connected to the terminal 109 to which the reference potential is applied. In other words, the fully bidirectional device includes as many diodes 101 whose cathodes are respectively connected to the terminal 103 as the diodes whose cathodes are connected to the terminal 109, so each terminal 103 is coupled to the terminal 109 through the series association of two diodes, wherein the two diodes are interconnected through their cathodes. However, the volume and cost of the fully bidirectional device will be greater than the volume and cost of the pseudo-bidirectional device 100.

[0068] Figure 2 is a circuit diagram illustrating an example of an electrostatic discharge protection device 200 according to one embodiment.

[0069] Figure 2 The device 200 includes Figure 1 These common elements will not be described in detail hereinafter. Figure 2 The device 200 and Figure 1 The difference of the device 100 is that Figure 2 The device 200 further includes n capacitor elements 201-1, 201-2, ..., 201-n connected in parallel with the n diodes 101-1, 101-2, ..., 101-n, respectively.

[0070] Each capacitor element 201-1, 201-2, ..., 201-n is more accurately a capacitor including two conductive electrodes or conductive plates (e.g., two metal electrodes parallel to each other) separated from each other by a dielectric material. As an example, the device 200 can have a monolithic structure, so each capacitor element 201-1, 201-2, ..., 201-n is a metal insulator metal (MIM) type capacitor, which is formed as a stack of conductive layers (e.g., metal layers), which are separated from each other by electrical insulating layers (e.g., dielectric layers). In addition, in the case where the device 200 is a monolithic type, the node 105 corresponds to, for example, a substrate having the device 200 formed therein and on the top thereof, for example, a semiconductor substrate. However, this example is not restrictive, and as a variation, the device 200 can be formed based on discrete components.

[0071] The capacitive elements 201-1, 201-2, ..., 201-n of the pseudo bidirectional electrostatic discharge protection device 200 have capacitances that are substantially equal to each other, for example, within manufacturing dispersions. As an example, the capacitances of the capacitive elements 201-1, 201-2, ..., 201-n are determined by a simulation tool according to one or more excitation frequencies of a signal that may be applied to the device 200 through coupling, so as to minimize harmonics generated by the device 200 at the frequency or frequencies.

[0072] An advantage of the pseudo-bidirectional electrostatic discharge protection device 200 lies in the fact that the presence of the capacitive elements 201 - 1 , 201 - 2 , . . . , 201 - n enables the power of harmonics to be reduced compared to the device 100 .

[0073] As an example, when each diode 101-1, 101-2, ..., 101-n has a capacitance equal to approximately 4.5 pF, diode 107 has a capacitance equal to approximately 38 pF, and each capacitive element 201-1, 201-2, ..., 201-n has a capacitance equal to approximately 10 pF, relative to the case of using device 100, due to device 200, for example, a power reduction of approximately -26 dB of the second-order harmonic is achieved for an excitation frequency of approximately 900 MHz, a power reduction of approximately -33 dB of the second-order harmonic is achieved for an excitation frequency of approximately 1.75 GHz, and a power reduction of approximately -37 dB of the second-order harmonic is achieved for an excitation frequency of approximately 2.55 GHz.

[0074] In addition, relative to device 100, due to device 200, for example, approximately 18 dB power reduction of the third-order harmonic is achieved for an excitation frequency of approximately 900 MHz, approximately -23 dB power reduction of the third-order harmonic is achieved for an excitation frequency of approximately 1.75 GHz, and approximately -25 dB power reduction of the third-order harmonic is achieved for an excitation frequency of approximately 2.55 GHz.

[0075] Figure 3 is a circuit diagram illustrating another example of an electrostatic discharge protection device 300 according to one embodiment.

[0076] Figure 3 The device 300 includes Figure 2 These common elements will not be described in detail hereinafter. Figure 3 The device 300 and Figure 2 The difference of the device 200 is that Figure 3 The device 300 further comprises n other capacitive elements 301-1, 301-2, ..., 301-n, respectively coupling the terminals 103-1, 103-2, ..., 103-n to the terminal 109 to which the reference potential is applied. More precisely, in Figure 2In the example illustrated in FIG, each capacitor element 301-1, 301-2, ..., 301-n includes a first electrode or terminal connected to the terminal 109 to which the reference potential is applied, and a second electrode or terminal connected to the corresponding terminal 103-1, 103-2, ..., 103-n. The capacitor elements 301-1, 301-2, ..., 301-n are different from the capacitor elements 201-1, 201-2, ..., 201-n.

[0077] The device 300 also includes n resistor elements 303-1, 303-2, ..., 303-n that couple the terminals 103-1, 103-2, ..., 103-n to the terminals 305-1, 305-2, ..., 305-n, respectively. The resistor elements 303-1, 303-2, ..., 303-n are, for example, resistors, each of which includes two conductive electrodes coupled by a resistive material, such as metal electrodes. As an example, the device 300 can have a monolithic structure, then each resistor element 303-1, 303-2, ..., 303-n is, for example, formed in a conductive layer (e.g., a metal layer) of the structure. However, this example is not restrictive, and as a variation, the device 300 can be formed based on discrete components.

[0078] The resistance elements 303 - 1 , 303 - 2 , . . . , 303 - n of the electrostatic discharge protection device 300 have capacitances that are substantially equal to each other within, for example, manufacturing variations.

[0079] Terminals 305-1, 305-2, ..., 305-n are, for example, input terminals, output terminals or input-output terminals of an integrated circuit or electronic component to be protected from electrostatic discharge. Each terminal 305-1, 305-2, ..., 305-n is, for example, configured to receive or send a digital signal or an analog signal, such as an analog signal with a frequency less than 10 MHz or 20 MHz. As an example, terminals 305-1, 305-2, ..., 305-n withstand a potential of about 3.3 V, about 5 V or about 15 V in nominal operation.

[0080] Generally, the device 300 includes n branches (where n is an integer greater than or equal to 2), each branch including a diode 101 coupling the terminal 103 to the node 105, a capacitive element 201 connected in parallel with the diode 101, another capacitive element 301 coupling the terminal 103 to the terminal 109, and a resistive element 303 coupling the terminal 103 to the terminal 305. In each branch of the device 300, the resistive element 303 and the capacitive element 301 form a resistor-capacitor (RC) filter, for example, a low-pass filter.

[0081] The capacitive elements 301-1, 301-2, ..., 301-n of the pseudo bidirectional electrostatic discharge protection device 300 have capacitances that are substantially equal to each other, for example, within manufacturing dispersions. For example, the capacitances of the capacitive elements 201-1, 201-2, ..., 201-n and the capacitive elements 301-1, 301-2, ..., 301-n are determined, for example, by means of a digital simulation tool, so that the device 300 has an impedance that is equal to the impedance of a device similar to the device 300 but without the capacitive elements 201-1, 201-2, ..., 201-n, while obtaining the maximum reduction of harmonics.

[0082] An advantage of the pseudo bidirectional ESD protection device 300 lies in the fact that the presence of the capacitive elements 201-1, 201-2, ..., 201-n enables the power of harmonics to be reduced compared to a device similar to the device 300 but with the capacitive elements 201-1, 201-2, ..., 201-n removed.

[0083] For example, each diode 101-1, 101-2, ..., 101-n has a capacitance equal to approximately 4.5 pF, the diode 107 has a capacitance equal to approximately 38 pF, or each capacitive element 201-1, 201-2, ..., 201-n has a capacitance equal to approximately 35 pF, each capacitive element 301-1, 301-2, ..., 301-n has a capacitance equal to approximately 55 pF, and each resistive element 303-1, 303-2, ..., 303-n has a capacitance equal to approximately 50 Ω, compared to the case of using a similar device having the same impedance but removing the capacitive elements 201-1, 201-2, ..., 201-n, due to the device 300, for example, approximately -42 dB power reduction of the second-order harmonic is achieved for an excitation frequency of approximately 900 MHz, approximately -38 dB power reduction of the second-order harmonic is achieved for an excitation frequency of approximately 1.75 GHz, and approximately -38 dB power reduction of the second-order harmonic is achieved for an excitation frequency of approximately 2.55 GHz.

[0084] Further, due to the device 300, for example, a power reduction of approximately -9 dB for the third-order harmonic is achieved for an excitation frequency of approximately 900 MHz, a power reduction of approximately -11 dB for the third-order harmonic is achieved for an excitation frequency of approximately 1.75 GHz, and a power reduction of approximately -11 dB for the third-order harmonic is achieved for an excitation frequency of approximately 2.55 GHz, compared to a case where a similar device having the same impedance is used but where the capacitive elements 201-1, 201-2, ..., 201-n are removed.

[0085] Various embodiments and variations have been described. Those skilled in the art will appreciate that certain features and variations of these various embodiments may be combined, and that other variations will occur to those skilled in the art. In particular, although Figure 3 An example application in which the pseudo bidirectional ESD protection device 300 implements a filtering function is illustrated, but the embodiments are not limited to this type of application, but may more generally be implemented in any type of integrated circuit or electronic component that may benefit from the presence of ESD protection.

[0086] Finally, based on the functional indications given above, the practical implementation of the described embodiments and variants is within the capabilities of a person skilled in the art. In particular, a person skilled in the art is able to determine, for example with the aid of digital simulation tools, the values ​​of the intrinsic capacitances of the diodes 101-1, 101-2, ..., 101-n and 107, the values ​​of the capacitances of the capacitive elements 201-1, 201-2, ..., 201-n, the values ​​of the capacitances of the capacitive elements 301-1, 301-2, ..., 301-n and the values ​​of the resistances of the resistive elements 303-1, 303-2, ..., 303-n, depending on the application, in order to optimize the reduction of the harmonics generated by the pseudo-bidirectional electrostatic discharge protection device 200 or 300 while being able to ensure that its function is identical or similar to that of a similar device in which the capacitive elements 201-1, 201-2, ..., 201-n are removed.

Claims

1. A pseudo-bidirectional electrostatic discharge protection device, characterized in that: The device comprises: a first diode coupling the first terminal to the intermediate node; a second diode coupling a second terminal to the intermediate node; and a third diode coupling the intermediate node to a third terminal to which a reference potential is applied; wherein the capacitance of the third diode is greater than the capacitance of the first diode and greater than the capacitance of the second diode; a first capacitive element connected in parallel with the first diode; and A second capacitance element is connected in parallel with the second diode.

2. The device according to claim 1, characterized in that: The first diode includes an anode electrode and a cathode electrode connected to the intermediate node and the first terminal, respectively; and The second diode includes an anode electrode and a cathode electrode connected to the intermediate node and the second terminal, respectively.

3. The device according to claim 1, characterized in that The third diode includes an anode electrode and a cathode electrode connected to the intermediate node and the third terminal, respectively.

4. The device according to claim 1, characterized in that The first capacitive element and the second capacitive element are capacitors.

5. The device according to claim 1, characterized in that The device has a monolithic structure.

6. The device according to claim 5, characterized in that The first capacitive element and the second capacitive element are capacitors, and wherein the first capacitive element and the second capacitive element are metal-insulator-metal (MIM) capacitors formed as a stack of conductive layers of the monolithic structure.

7. The device according to claim 1, characterized in that The device also includes: a third capacitive element coupling the first terminal to the third terminal; and A fourth capacitive element couples the second terminal to the third terminal.

8. The device according to claim 7, characterized in that The device also includes: a first resistive element coupling the first terminal to a fourth terminal; and A second resistive element couples the second terminal to a fifth terminal.

9. The device according to claim 8, characterized in that: The third capacitive element and the fourth capacitive element each have a capacitance equal to approximately 55 pF; and The first resistive element and the second resistive element each have a resistance equal to approximately 50Ω.

10. The device according to claim 1, characterized in that The first diode, the second diode, and the third diode are Zener diodes.

11. The device according to claim 1, characterized in that The first diode, the second diode, and the third diode are transient voltage suppressor diodes.

12. The device according to claim 1, characterized in that The first capacitive element and the second capacitive element have substantially the same capacitance as each other.

13. The device according to claim 1, characterized in that The first capacitive element and the second capacitive element each have a capacitance equal to approximately 10 pF.

14. The device according to claim 1, characterized in that The capacitance of the third diode is at least twice the capacitance of the first diode and the second diode.

15. The device according to claim 1, characterized in that The capacitance of the third diode is at least five times greater than the capacitance of the first diode and the second diode.

16. The device according to claim 1, characterized in that The capacitance of the third diode is approximately ten times greater than the capacitance of the first diode and the second diode.

17. The device according to claim 1, characterized in that: The first diode and the second diode each have a capacitance equal to approximately 4.5 pF; and The third diode has a capacitance equal to approximately 38 pF.

18. The device according to claim 1, characterized in that The first terminal and the second terminal are input terminals and / or output terminals of the integrated circuit.

19. The device according to claim 1, characterized in that The intermediate node corresponds to a semiconductor substrate in which and on top of which the device is formed.

20. A pseudo-bidirectional electrostatic discharge protection device, characterized in that: The device comprises: a first diode having a first capacitance, the first diode having an anode connected to the intermediate node and a cathode connected to the first terminal; a first capacitor having a first node connected to the intermediate node and a second node connected to the first terminal; a second diode having a second capacitance, the first diode having an anode connected to the intermediate node and a cathode connected to the second terminal; a second capacitor having a first node connected to the intermediate node and a second node connected to the second terminal; a third diode having a third capacitance, the third diode having an anode connected to the intermediate node and a cathode connected to a third terminal; a third capacitor having a first node connected to the first terminal and a second node connected to the third terminal; and a fourth capacitor having a first node connected to the second terminal and a second node connected to the third terminal; The third capacitor is larger than the first capacitor and the second capacitor.

21. The device according to claim 20, characterized in that The first diode, the second diode, and the third diode are Zener diodes.

22. The device according to claim 20, characterized in that The first diode, the second diode, and the third diode are transient voltage suppressor diodes.

23. The device according to claim 20, characterized in that The first terminal and the second terminal are input terminals and / or output terminals of the integrated circuit.

24. The device according to claim 20, characterized in that The intermediate node corresponds to a semiconductor substrate in which and on top of which the device is formed.

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