Circuit for protection of overvoltage occurring during overcurrent protection, voltage conversion device and vehicle

Abstract

The utility model relates to a circuit for overvoltage protection occurring during overcurrent protection, a voltage conversion device and a vehicle. A circuit for protection of an overvoltage occurring during overcurrent protection includes: a first diode and a second diode, the cathodes of which are coupled to a first node; a first transient voltage suppressor diode having a cathode coupled to a second node and an anode coupled to an anode of the first diode; the cathode of the thyristor is coupled to the anode of the second diode, the anode of the thyristor is coupled to the second node, and the grid of the thyristor is coupled to the anode of the first diode; and a switch having a first terminal coupled to the first node.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to French Patent Application No. FR2303191, filed on March 31, 2023, entitled “Circuit de protection contreles surtensions,” and U.S. Patent Application No. 18 / 606,918, filed on March 15, 2024, entitled “Overvoltages protection circuit,” which are incorporated herein by reference to the maximum extent permitted by law. Technical Field

[0003] The present disclosure relates generally to the field of power electronics, and more particularly to electronic devices and circuits adapted for overvoltage protection during overcurrent protection. Background Art

[0004] Currently, it is crucial to equip electronic systems and devices with overcurrent and overvoltage protection circuits. In fact, the occurrence of overcurrent or overvoltage can seriously damage unprotected systems or devices.

[0005] It would be desirable to be able to improve, at least in part, certain aspects of overvoltage protection circuits. Utility Model Content

[0006] High performance over-current and over-voltage protection circuits are required.

[0007] Bidirectional overcurrent and overvoltage protection circuits are required.

[0008] Embodiments overcome all or some of the disadvantages of known overvoltage and overcurrent protection circuits.

[0009] An embodiment provides a circuit for protecting against overvoltage occurring during overcurrent protection, the circuit comprising:

[0010] - a first diode and a second diode having cathodes coupled to the first node;

[0011] - a first transient voltage suppressor diode having a cathode coupled to the second node and an anode coupled to the anode of the first diode;

[0012] - a thyristor having a cathode coupled to the anode of the second diode, an anode coupled to the second node, and a gate coupled to the anode of the first diode; and

[0013] - a switch having a first terminal coupled to the first node.

[0014] According to an embodiment, the first diode is a PN junction diode.

[0015] According to an embodiment, the second diode is a Schottky diode.

[0016] According to an embodiment, the second diode is a PN junction diode.

[0017] According to an embodiment, the first diode and the second diode have a reverse bias voltage greater than a maximum supply voltage.

[0018] According to an embodiment, the maximum supply voltage is greater than 14V.

[0019] According to an embodiment, the supply voltage is adapted to be applied between a second terminal of the switch different from the first terminal and the second node.

[0020] According to an embodiment, the first transient voltage suppressor diode has an avalanche voltage greater than a voltage delivered by a load.

[0021] According to an embodiment, the circuit further comprises at least one second transient voltage suppressor diode arranged in series between a cathode of the first transient voltage suppressor diode and the second node.

[0022] According to an embodiment, the switch is one or more NMOS type transistors.

[0023] According to an embodiment, the switch is one or more PMOS type transistors.

[0024] According to an embodiment, the load is adapted to be connected between the first node and the second node.

[0025] According to an embodiment, the load is a battery.

[0026] According to an embodiment, the circuit further comprises:

[0027] - a third transient voltage suppressor diode having a cathode coupled to the first node; and

[0028] - a third diode having an anode coupled to the anode of the third transient voltage suppressor diode and a cathode coupled to the second node.

[0029] Another embodiment provides a voltage conversion device including the circuit described above.

[0030] Another embodiment provides a vehicle including the circuit described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The foregoing features and advantages as well as other features and advantages will be described in detail in the remainder of the disclosure of specific embodiments given by way of illustration and not limitation, with reference to the accompanying drawings, in which:

[0032] Figure 1 A first embodiment of an overcurrent and overvoltage protection circuit is shown;

[0033] Figure 2 Shows the representation Figure 1 a graph of the operation of an embodiment of the invention; and

[0034] Figure 3 A first embodiment of an overcurrent and overvoltage protection circuit is shown. DETAILED DESCRIPTION

[0035] In the various drawings, the same features have been designated by the same reference numerals. In particular, common structural and / or functional features among the various embodiments may have the same reference numerals and may have the same structure, dimensions and material properties.

[0036] For the sake of clarity, only the steps and elements that facilitate the understanding of the described embodiments have been illustrated and described in detail.

[0037] Unless otherwise indicated, when referring to two elements being connected together, this means directly connected without any intermediate elements except conductors, and when referring to two elements being coupled together, this means the two elements can be connected or they can be coupled via one or more other elements.

[0038] In the following description, unless otherwise specified, when terms defining absolute positions (such as terms "front", "back", "top", "bottom", "left", "right", etc.) or terms defining relative positions (such as terms "above", "directly below", "up", "down", etc.) or terms defining directions (such as terms "horizontal", "vertical", etc.) are mentioned, they refer to the orientation of the drawings.

[0039] Unless otherwise indicated, the expressions "about", "approximately", "substantially" and "approximately" mean plus or minus 10%, preferably plus or minus 5%.

[0040] Figure 1 An embodiment of an overcurrent and overvoltage protection circuit 100 is shown. More specifically, the circuit 100 is a circuit for protection against overvoltages that occur during overcurrent protection.

[0041] The circuit 100 is adapted to be placed between a power supply 101 (SUPP) and a load. The power supply 101 delivers a supply voltage between a node IN101 and a node GND101 and delivers a supply current on the node IN101. According to an example, the node GND101 is a reference node, that is, a node receiving a reference potential, such as ground.

[0042] exist Figure 1, the load is a battery BAT101, and a parasitic inductance L101 is shown to be connected in series with the battery BAT101. According to the example, the parasitic inductance L101 represents the parasitic inductance of the wire that couples the battery BAT101 to other electronic devices or components. Therefore, the inductance L101 and the battery BAT101 are assembled in series between the node VDD101 and the reference node GND101.

[0043] According to an example, the battery BAT101 is a rechargeable battery, such as a motor vehicle battery. According to a preferred example, the battery BAT101 is an auxiliary battery of a motor vehicle. According to an example, the circuit 100 may form part of a voltage conversion device adapted to power an auxiliary battery of a motor vehicle.

[0044] According to another example, the load may form part of a power train, an induction cooker, a photovoltaic panel, etc. More generally, the circuit 100 may form part of any converter of a DC voltage to another DC voltage and a charger using a DC voltage, which charger may form part of an electronic device belonging to the list of systems described previously.

[0045] Circuit 100 includes a short circuit or overcurrent protection switch M101. According to an example, switch M101 is a transistor or multiple transistors assembled in parallel. According to an embodiment, switch M101 is one or more insulated gate field effect transistors or metal oxide semiconductor field effect transistors (currently more referred to as MOSFET transistors or MOS transistors). More specifically, and according to an example, transistor M101 is one or more N-channel MOS type transistors, also referred to as NMOS transistors. According to another example, transistor M101 is one or more P-channel MOS transistors, also referred to as PMOS transistors.

[0046] A first conductive terminal of the switch M101 is coupled (preferably, connected) to the node IN101 , and a second conductive terminal of the switch M101 is coupled (preferably, connected) to the node VDD101 .

[0047] The circuit also includes a diode D101 and a transient voltage suppressor diode TVS101 between the node VDD101 and the node GND101.

[0048] The cathode of diode D101 is coupled (preferably connected) to node VDD101, and the anode of diode D101 is coupled (preferably connected) to node N101. According to an example, diode D101 is a conventional PN junction diode, that is to say a diode formed in a semiconductor substrate. According to an embodiment, diode D101 has a reverse bias voltage greater than a maximum supply voltage Vmax, currently referred to as voltage VRRM. According to an example, the maximum supply voltage Vmax is greater than 14V, for example about 24V. According to a variant, diode D101 can be replaced by a plurality of other diodes assembled in series.

[0049] Transient voltage suppressor diode TVS101 (TVS) is hereinafter referred to as TVS diode TVS101 or Transil diode. Figure 1 101 is represented by the same electronic symbol as a Zener diode. The TVS diode TVS101 is adapted to withstand a voltage provided by a load (here, a battery BAT101) between its terminals. Therefore, the TVS diode TVS101 has a clamping voltage greater than or equal to the voltage of the battery BAT101. According to an embodiment, the clamping voltage of the TVS diode TVS101 is greater than or equal to 14V. The anode of the TVS diode TVS101 is coupled (preferably connected) to the node N101, and the cathode of the TVS diode TVS101 is coupled (preferably connected) to the node GND101.

[0050] According to an alternative embodiment, the TVS diode TVS101 may be formed of a plurality of TVS diodes arranged in series in the same direction between the node N101 and GND101 .

[0051] The circuit also includes a diode D102 and a thyristor T101 between the node VDD101 and the node GND101.

[0052] The cathode of diode D102 is coupled (preferably, connected) to node VDD101. According to a first example, diode D102 is a conventional PN junction diode, that is, a diode formed in a semiconductor substrate. According to a second example, diode D102 is a Schottky diode. According to an embodiment, diode D102 has a reverse bias voltage greater than the maximum supply voltage Vmax described above.

[0053] The thyristor T101 is a silicon controlled rectifier (SCR). The cathode of the thyristor T101 is coupled (preferably connected) to the anode of the diode D102, and the anode of the thyristor T101 is coupled (preferably connected) to the node GND101. The gate of the thyristor T101 is coupled (preferably connected) to the node N101.

[0054] Combination Figure 2 The operation of circuit 100 is described.

[0055] Figure 2 is a graph showing two curves 201 and 202, which represent the combination of Figure 1 The operation of circuit 100 is described.

[0056] More specifically, curve 202 is a timing chart showing changes in voltage VDD obtained between nodes GND101 and VDD101. Curve 201 is a timing chart showing changes in overcurrent appearing at the input of battery BAT101 (that is, at the level appearing at node VDD101) via inductor L101.

[0057] The operation of circuit 100 is as follows.

[0058] In normal operation mode, the power supply 101 delivers a supply voltage and a supply current to a load, that is to say here a battery BAT101. For this purpose, the switch M101 is conductive and the diodes D101 and D102 are adapted to block the current originating from the node VDD101. The TVS diode TVS101 and the thyristor T101 are non-conductive.

[0059] If the load BAT101 is mistakenly assembled in reverse, the voltage of the load BAT101 is blocked by the TVS diode TVS101, which has an avalanche voltage greater than the voltage of the battery BAT101. The thyristor T101 is still blocked because no current is supplied to its gate. The battery BAT101 is therefore not discharged by the overvoltage protection circuit.

[0060] In the event of a short circuit or overcurrent (this is Figure 2), the current increases rapidly and the switch M101 detects a short circuit or an overcurrent. The switch M101 becomes non-conductive. The overvoltage caused by the sudden cutoff of the current through the cables coupling the battery (these cables have an inductance represented by the coil L101) appears at the level of the protection circuit 100, and more specifically, at the level of the TVS diode TVS101 and the diode D101. When this overvoltage is greater than the sum of the clamping voltage of the TVS diode TVS101 and the forward bias voltage of the diode D101, the current flows through the diode D101. When the voltage across the diode D101 is strong enough, that is, when the voltage across the diode 101 is greater than the maximum voltage that can be applied between the gate and cathode of the thyristor T101 without turning it on, the current flows through the gate of the thyristor T101 and reaches the level of the cathode of the thyristor T101 and the anode of the diode D102. The thyristor T101 is then switched on and conducts the overvoltage, which is then carried to the reference node GND101 , and operates like a freewheeling diode. The load is therefore not powered.

[0061] An advantage of the circuit 100 is that it allows the power supply circuit and the circuit powered by the battery BAT101 to be protected from possible overvoltages that can occur as a result of the occurrence of an overcurrent blocked by the switch M101 .

[0062] Figure 3 An embodiment of an overcurrent and overvoltage protection circuit 200 is shown.

[0063] The protection circuit 200 is similar to the combination of Figure 1 Protection circuit 100 is described. Elements common to circuits 100 and 200 are not described again in detail here, and only the differences between circuits 100 and 200 are emphasized.

[0064] Thus, like circuit 100, circuit 200 is adapted to be placed between a power supply 101 (SUPP) and a load. Figure 1 Same as in Figure 2 In FIG. 1 , the load is the battery BAT101 and the parasitic inductor L101.

[0065] Similarly, like circuit 100, circuit 200 includes:

[0066] - Switch M101;

[0067] - diode D101 and TVS diode TVS101; and

[0068] -Diode D102 and thyristor T101.

[0069] The circuit also comprises a TVS diode TVS201 and a diode D201. These two components are intended to remove overvoltages that may appear between nodes VDD101 and GND101. According to an example, the diode D201 is adapted to have a reverse bias voltage greater than a limit voltage Vlim defined by the circuit to be protected.

[0070] The cathode of TVS diode TVS201 is coupled (preferably connected) to node VDD101, and the anode of TVS diode TVS201 is coupled (preferably connected) to the anode of diode D201. Cathode D201 of diode D201 is coupled (preferably connected) to node GND101.

[0071] According to an embodiment, the TVS diode TVS201 is adapted to suppress a positive overvoltage occurring between the nodes VDD101 and GND101. According to an embodiment, the diode D201 is adapted to block a negative overvoltage occurring between the nodes VDD101 and GND101. According to a variant, the TVS diode TVS201 may be replaced by a plurality of diodes assembled in series.

[0072] An advantage of circuit 200 is that it allows bidirectional protection of a load from overvoltages caused by overcurrent protection.

[0073] Various embodiments and variations have been described. Those skilled in the art will appreciate that certain features of these various embodiments and variations may be combined, and those skilled in the art will recognize other variations.

[0074] 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.

Claims

1. A circuit for protecting against overvoltage occurring during overcurrent protection, characterized in that: include: - a first diode and a second diode having cathodes coupled to the first node; - a first transient voltage suppressor diode having a cathode coupled to the second node and an anode coupled to the anode of the first diode; a thyristor having a cathode coupled to the anode of the second diode, an anode coupled to the second node, and a gate coupled to the anode of the first diode; and - a switch having a first terminal coupled to the first node.

2. The circuit for protecting against overvoltage occurring during overcurrent protection as claimed in claim 1, wherein the first diode is a PN junction diode.

3. The circuit for protecting against overvoltage occurring during overcurrent protection as claimed in claim 1, wherein the second diode is a Schottky diode.

4. The circuit for protecting against overvoltage occurring during overcurrent protection as claimed in claim 1, wherein the second diode is a PN junction diode.

5. The circuit for protecting against overvoltage occurring during overcurrent protection as claimed in claim 1, wherein the first diode and the second diode have a reverse bias voltage greater than a maximum supply voltage.

6. The circuit for protecting against overvoltage occurring during overcurrent protection as claimed in claim 5, wherein the maximum supply voltage is greater than 14V.

7. The circuit for protecting against overvoltage occurring during overcurrent protection as claimed in claim 1, wherein the supply voltage is adapted to be applied between a second terminal of the switch different from the first terminal and the second node.

8. The circuit for protecting against overvoltage occurring during overcurrent protection as claimed in claim 1, wherein the first transient voltage suppressor diode has an avalanche voltage greater than a voltage delivered by a load.

9. The circuit for protecting against overvoltage occurring during overcurrent protection as claimed in claim 1, characterized in that: Also includes: At least one second transient voltage suppressor diode is arranged in series between a cathode of the first transient voltage suppressor diode and the second node.

10. The circuit for protecting against overvoltage occurring during overcurrent protection as claimed in claim 1, wherein the switch is one or more NMOS type transistors.

11. The circuit for protecting against overvoltage occurring during overcurrent protection as claimed in claim 1, wherein the switch is one or more PMOS type transistors.

12. The circuit for protecting against overvoltage occurring during overcurrent protection as claimed in claim 1, wherein the load is adapted to be connected between the first node and the second node.

13. The circuit for protecting against overvoltage occurring during overcurrent protection as claimed in claim 12, wherein the load is a battery.

14. The circuit for protecting against overvoltage occurring during overcurrent protection as claimed in claim 1, characterized in that: Also includes: - a third transient voltage suppressor diode having a cathode coupled to the first node; and - a third diode having an anode coupled to the anode of the third transient voltage suppressor diode and a cathode coupled to the second node.

15. A voltage conversion device, characterized in that: Comprising the circuit as claimed in claim 1.

16. A vehicle, characterized in that: Comprising the circuit as claimed in claim 1.

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