Diode-triggered Triac Devices and Circuits

Abstract

The present application provides a diode-triggered triac device and circuit. The device includes: a P-type substrate; a first P-well formed within the P-type substrate, with a first P-type doped region and a first N-type doped region formed within the first P-well; a second P-well formed within the P-type substrate, with a third N-type doped region and a fourth P-type doped region formed within the second P-well; an N-well formed within the P-type substrate, with a second P-type doped region, a second N-type doped region, and a third P-type doped region formed within the N-well; the second N-type doped region is electrically connected to the positive electrode of the diode string, and the first P-type doped region and the fourth P-type doped region are electrically connected to the negative electrode of the diode string. The present application realizes adjustable bidirectional trigger voltage and saves layout area by commonly connecting diodes.

Description

Technical Field

[0001] This application belongs to the technical field of integrated circuit electrostatic discharge protection, and particularly relates to a thyristor device and circuit for low-voltage bidirectional ESD (Electro-Static Discharge) protection. Background Art

[0002] Basic characteristic requirements for ESD protection: high sensitivity, high robustness, low on-resistance, low leakage, and low capacitance. Therefore, commonly used components include diodes, metal-oxide-semiconductor field-effect transistors (MOS), bipolar transistors, silicon controlled rectifier (SCR) devices, etc. Among them, SCRs have received extensive attention from ESD researchers due to their high robustness and small leakage current. Generally, SCR devices are unidirectional ESD protection devices, and ESD protection in the other direction is completed by a parasitic diode or by connecting a diode in parallel. Using an additional diode for ESD protection in the other direction will increase the layout area. In some circuits where the input port needs to withstand negative voltage, if the anode voltage is lower than -0.7V and the cathode voltage is 0V, when using a diode for reverse protection, the diode will conduct during normal operation, resulting in leakage. In this case, a bidirectional SCR structure must be used for protection. Summary of the Invention

[0003] This application provides a diode-triggered thyristor device and circuit, which realizes adjustable bidirectional trigger voltage and saves layout area through a common-connected diode.

[0004] In the first aspect of the embodiments of this application, a diode-triggered thyristor device is provided, including a silicon controlled rectifier and a diode string. The silicon controlled rectifier has an anode and a cathode and includes:

[0005] A P-type substrate;

[0006] A first P-well formed in the P-type substrate, with a first P-type doped region and a first N-type doped region formed in the first P-well;

[0007] A second P-well formed in the P-type substrate, with a third N-type doped region and a fourth P-type doped region formed in the second P-well;

[0008] An N-well formed in the P-type substrate, with a second P-type doped region, a second N-type doped region, and a third P-type doped region formed in the N-well;

[0009] Among them, the first N-type doping region, the third P-type doping region are electrically connected to the anode; the third N-type doping region, the second P-type doping region are electrically connected to the cathode; the second N-type doping region is electrically connected to the positive electrode of the diode string, and the first P-type doping region and the fourth P-type doping region are electrically connected to the negative electrode of the diode string.

[0010] In some embodiments, the first P-type doping region, the second P-type doping region, the third P-type doping region, the fourth P-type doping region, the first N-type doping region, the second N-type doping region, and the third N-type doping region are all heavily doped regions, and the first P-well, the second P-well, and the N-well are all lightly doped regions.

[0011] In some embodiments, the first P-well and the second P-well are adjacent to the N-well, and the first P-well and the second P-well are symmetrically distributed with respect to the central axis of the N-well; wherein, the first P-type doping region and the fourth P-type doping region are symmetric with respect to the central axis of the N-well, the first N-type doping region and the third N-type doping region are symmetric with respect to the central axis of the N-well, and the second P-type doping region and the third P-type doping region are symmetric with respect to the central axis of the N-well.

[0012] In some embodiments, when viewed in the direction from the first P-well, through the N-well to the second P-well, the doping regions are, in sequence, the first P-type doping region, the first N-type doping region, the second P-type doping region, the second N-type doping region, the third P-type doping region, the third N-type doping region, and the fourth P-type doping region.

[0013] In some embodiments, a deep N-well is formed in the substrate, and the first P-well, the N-well, and the second P-well are disposed on the upper surface of the deep N-well.

[0014] In some embodiments, a shallow trench isolation structure is formed between adjacent doping regions, and the depth of each doping region is less than the depth of the shallow trench isolation structure.

[0015] In some embodiments, the number of diodes in the diode string is greater than or equal to 0.

[0016] In some embodiments, the diode string includes a fifth diode and a sixth diode;

[0017] The positive electrode of the fifth diode is the positive electrode of the diode string, the negative electrode of the fifth diode is connected to the positive electrode of the sixth diode, and the negative electrode of the sixth diode is the negative electrode of the diode string.

[0018] A second aspect of the embodiments of the present application provides a diode-triggered circuit, including:

[0019] Forward diode trigger circuit, the forward diode trigger circuit includes a first diode, a diode string and a second diode;

[0020] Reverse diode trigger circuit, the reverse diode trigger circuit includes a third diode, a diode string and a fourth diode;

[0021] Forward SCR circuit, the forward SCR circuit includes a first PNP bipolar transistor and the first NPN bipolar transistor;

[0022] Reverse SCR circuit, the reverse SCR circuit includes a second PNP bipolar transistor and a second NPN bipolar transistor;

[0023] The forward diode trigger circuit and the reverse diode trigger circuit share the diode string.

[0024] In some embodiments, the positive electrode of the first diode is connected to the anode, the negative electrode of the first diode is connected to the positive electrode of the diode string, the negative electrode of the diode string is connected to the positive electrode of the second diode, and the negative electrode of the second diode is connected to the cathode; starting from the anode, passing through the first diode, the diode string, the second diode to the cathode, a forward diode trigger circuit is formed.

[0025] In some embodiments, the positive electrode of the third diode is connected to the cathode, the negative electrode of the third diode is connected to the positive electrode of the diode string, the negative electrode of the diode string is connected to the positive electrode of the fourth diode, and the negative electrode of the fourth diode is connected to the anode; starting from the cathode, passing through the third diode, the diode string, the fourth diode to the anode, a reverse diode trigger circuit is formed.

[0026] In some embodiments, the base of the first PNP bipolar transistor is the collector of the first NPN bipolar transistor, the base of the first NPN bipolar transistor is the collector of the first PNP bipolar transistor, the base of the first PNP bipolar transistor is connected to the positive electrode of the diode string, the collector of the first PNP bipolar transistor is connected to the negative electrode of the diode string, the emitter of the first PNP bipolar transistor is connected to the anode, and the emitter of the first NPN bipolar transistor is connected to the cathode; starting from the anode, passing through the first PNP bipolar transistor, the first NPN bipolar transistor to the cathode, a forward SCR circuit is formed.

[0027] In some embodiments, the base of the second PNP bipolar transistor is the collector of the second NPN bipolar transistor, the base of the second NPN bipolar transistor is the collector of the second PNP bipolar transistor, the base of the second PNP bipolar transistor is connected to the positive electrode of the diode string, the collector of the second PNP bipolar transistor is connected to the negative electrode of the diode string, the emitter of the second NPN bipolar transistor is connected to the anode, and the emitter-collector of the second PNP bipolar transistor is connected to the cathode; starting from the cathode, passing through the second PNP bipolar transistor and the second NPN bipolar transistor to reach the anode, a reverse SCR circuit is formed.

[0028] In some embodiments, the number of diodes in the diode string is greater than or equal to 0.

[0029] In some embodiments, the diode string includes a fifth diode and a sixth diode;

[0030] The positive electrode of the fifth diode is the positive electrode of the diode string, the negative electrode of the fifth diode is connected to the positive electrode of the sixth diode, and the negative electrode of the sixth diode is the negative electrode of the diode string.

[0031] The third aspect of the embodiments of the present application provides an integrated circuit triggered by a diode, including the diode-triggered circuit as described above.

[0032] The above technical solutions of the present application have the following beneficial technical effects:

[0033] The diode-triggered triac device and circuit of the present application achieve adjustable bidirectional trigger voltage and save layout area through the common connection of diodes. Description of the Drawings

[0034] Figure 1 is a schematic structural diagram of a triac device provided by an embodiment of the present application;

[0035] Figure 2 is an equivalent circuit diagram of a triac device provided by an embodiment of the present application;

[0036] Figure 3 is the simulation result of the forward TLP test of a triac device provided by an embodiment of the present application Figure 1 ;

[0037] Figure 4 is the simulation result of the reverse TLP test of a triac device provided by an embodiment of the present application Figure 2 .

[0038] Reference Signs:

[0039] 100. Silicon controlled rectifier; 1. P-type substrate; 2. Deep N-well; 3. First P-well; 4. N-well; 5. Second P-well; 6. First trench; 7. Second trench; 8. Third trench; 9. Fourth trench; 10. Fifth trench; 11. Sixth trench; 12. First P-type doped region; 13. First N-type doped region; 14. Second P-type doped region; 15. Second N-type doped region; 16. Third P-type doped region; 17. Third N-type doped region; 18. Fourth P-type doped region; 200. Diode string; 101. First PNP bipolar transistor; 102. Second PNP bipolar transistor; 103. First NPN bipolar transistor; 104. Second NPN bipolar transistor; 105. First diode; 106. Second diode; 107. Third diode; 108. Fourth diode; 201. Fifth diode; 202. Sixth diode. Detailed implementation manner

[0040] Example embodiments will now be described more fully with reference to the accompanying drawings. However, the example embodiments can be implemented in various forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more complete and comprehensive, and will fully convey the concept of the example embodiments to those skilled in the art. The features, structures, or characteristics described may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of the embodiments of the present application.

[0041] The features, structures, or characteristics described may be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a thorough understanding of the embodiments of the present application. However, those skilled in the art will realize that the technical solutions of the present application can be practiced without one or more of the specific details, or other methods, components, materials, etc. may be used. In other cases, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring the main technical concept of the present application.

[0042] The terms "a", "an", and "the" are used to denote the presence of one or more elements / components / etc.; the terms "comprising" and "having" are used to mean an open inclusion and mean that there may be additional elements / components / etc. in addition to the listed elements / components / etc. The terms "first" and "second", etc. are used only as labels and are not a limitation on the quantity of their objects.

[0043] Generally, an SCR device is a unidirectional ESD protection device, and the ESD protection in the other direction is completed by a parasitic diode or by connecting a diode in parallel. Using an additional diode for ESD protection in the other direction will increase the layout area. In some circuits where the input port needs to withstand negative voltage, if the anode voltage is lower than -0.7V and the cathode voltage is 0V, when using a diode for reverse protection, the diode will conduct during normal operation, resulting in leakage. At this time, a bidirectional SCR structure must be used for protection.

[0044] The applicant found through research that by sharing a diode, the bidirectional trigger voltage can be adjusted and the layout area can be saved.

[0045] As Figure 1 shown, a diode-triggered bidirectional thyristor device includes a silicon controlled rectifier 100 and a diode string 200. The silicon controlled rectifier 100 has an anode A and a cathode D and includes:

[0046] A P-type substrate 1;

[0047] A first P-well 3 formed in the P-type substrate 1, and a first P-type doped region 12 and a first N-type doped region 13 are formed in the first P-well 3;

[0048] A second P-well 5 formed in the P-type substrate 1, and a third N-type doped region 17 and a fourth P-type doped region 18 are formed in the second P-well 5;

[0049] An N-well 4 formed in the P-type substrate 1, and a second P-type doped region 14, a second N-type doped region 15 and a third P-type doped region 16 are formed in the N-well 4;

[0050] Among them, the first N-type doped region 13, the third P-type doped region 16 are electrically connected to the anode A; the third N-type doped region 17, the second P-type doped region 14 are electrically connected to the cathode D; the second N-type doped region 15 is electrically connected to the positive electrode of the diode string 200, and the first P-type doped region 12 and the fourth P-type doped region 18 are electrically connected to the negative electrode of the diode string 200.

[0051] Specifically, the third P-type doped region 16 and the N-well 15 are equivalent to a first diode 105, the third N-type doped region 17 and the second P-well 5 are equivalent to a second diode 106, the second P-type doped region 14 and the N-well 4 are equivalent to a third diode 107, and the first N-type doped region 13 and the first P-well 3 are equivalent to a fourth diode 108. The third P-type doped region 16, the N-well 4, and the second P-well 5 are equivalent to a first PNP bipolar transistor 101, the N-well 4, the second P-well 5, and the third N-type doped region 17 are equivalent to a first NPN bipolar transistor 103, the second P-type doped region 14, the N-well 4, and the first P-well 3 are equivalent to a second PNP bipolar transistor 102, and the N-well 4, the first P-well 3, and the first N-type doped region 13 are equivalent to a second NPN bipolar transistor 104.

[0052] The equivalent circuit diagram of the diode-triggered thyristor device is as Figure 2 shown. The positive pole of the diode string 200 is connected to the negative pole of the first diode 105, the negative pole of the third diode 107, the base of the first PNP bipolar transistor 101, the base of the second PNP bipolar transistor 102, the collector of the first NPN bipolar transistor 103, and the collector of the second NPN bipolar transistor 104. The negative pole of the diode string 200 is connected to the positive pole of the second diode 106, the positive pole of the fourth diode 108, the collector of the first PNP bipolar transistor 101, the collector of the second PNP bipolar transistor 102, the base of the first NPN bipolar transistor 103, and the base of the second NPN bipolar transistor 104. The positive pole of the first diode 105, the negative pole of the fourth diode 108, and the emitter of the first PNP bipolar transistor 101 and the emitter of the second NPN bipolar transistor 104 are connected to the anode A of the thyristor rectifier circuit. The negative pole of the second diode 106, the positive pole of the third diode 107, and the emitter of the first NPN bipolar transistor 103 and the emitter of the second PNP bipolar transistor 102 are connected to the cathode D of the thyristor rectifier circuit.

[0053] Among them, the first PNP bipolar transistor 101 and the first NPN bipolar transistor 103 form a forward SCR loop, the second PNP bipolar transistor 102 and the second NPN bipolar transistor 104 form a reverse SCR loop, the first diode 105, the diode string 200, and the second diode 106 form a forward diode trigger circuit, and the third diode 107, the diode string 200, and the fourth diode 108 form a reverse diode trigger circuit.

[0054] In this embodiment, the forward diode trigger circuit and the reverse diode trigger circuit share the external diode string 200, achieving adjustable bidirectional trigger voltage and saving layout area through the shared diode.

[0055] Operating principle of the triac device:

[0056] When the anode A encounters an ESD discharge event, the voltage of the anode A rises rapidly, the forward diode trigger path conducts, forming a trigger current. The PN junction formed by the base and emitter of the first PNP bipolar transistor 101 is forward-biased and conducts. At the same time, the collector current of the first PNP bipolar transistor 101 is the base current of the first NPN bipolar transistor 103. Therefore, the first NPN bipolar transistor 103 conducts. At the same time, the collector current of the first NPN bipolar transistor 103 is the base current of the first PNP bipolar transistor 101. Therefore, the first NPN bipolar transistor 103 and the first PNP bipolar transistor 101 form positive feedback, thereby generating a low-resistance ESD discharge path.

[0057] When the cathode D encounters an ESD discharge event, the voltage of the cathode D rises rapidly, the reverse diode trigger path conducts, forming a trigger current. The PN junction formed by the base and emitter of the second PNP bipolar transistor 102 is forward-biased and conducts. At the same time, the collector current of the second PNP bipolar transistor 102 is the base current of the second NPN bipolar transistor 104. Therefore, the second NPN bipolar transistor 104 conducts. At the same time, the collector current of the second NPN bipolar transistor 104 is the base current of the second PNP bipolar transistor 102. Therefore, the second NPN bipolar transistor 104 and the second PNP bipolar transistor 102 form positive feedback, thereby generating a low-resistance ESD discharge path.

[0058] To prove the effect of the triac device in this embodiment, the following is verified through simulation experiments.

[0059] Figure 3 is the simulation result of the forward TLP test of the triac device provided by an embodiment of the present application Figure 1 .

[0060] Specifically, the two curves respectively represent the simulation curves with the number of external diode strings 200 being 0 and 1. Refer to Figure 3 , in the TLP test, the state where the anode A current rises from 0 A to 1.32 A within 10 nanoseconds and lasts for 100 nanoseconds is used to simulate the situation of a forward ESD discharge event in the protection circuit. The output is the forward overshoot voltage when the thyristor circuit conducts. It can be seen that the overshoot voltages in the two cases are 1.9 V and 2.8 V respectively, and the appropriate structure can be selected according to the specific protection window.

[0061] Figure 4It is the simulation result of the reverse TLP test of the thyristor device provided by an embodiment of the present application Figure 2 。

[0062] Specifically, the two curves respectively represent the simulation curves with the number of externally connected diode strings 200 being 0 and 1. Refer to Figure 4 In the TLP test, the state where the cathode D current rises from 0 A to 1.32 A within 10 nanoseconds and lasts for 100 nanoseconds is used to simulate the situation of the reverse ESD discharge event of the protection circuit, and the output is the reverse overshoot voltage when the thyristor circuit conducts. It can be seen that the overshoot voltages in the two cases are also 1.9 V and 2.8 V respectively, which is completely symmetric with the forward direction.

[0063] In some embodiments, the first P-type doped region 12, the second P-type doped region 14, the third P-type doped region 16, the fourth P-type doped region 18, the first N-type doped region 13, the second N-type doped region 15, and the third N-type doped region 17 are all heavily doped regions, and the first P-well 3, the second P-well 5, and the N-well 4 are all lightly doped regions.

[0064] In some embodiments, the first P-well 3 and the second P-well 5 are adjacent to the N-well 4, and the first P-well 3 and the second P-well 5 are symmetrically distributed with respect to the central axis of the N-well 4; wherein, the first P-type doped region 12 and the fourth P-type doped region 18 are symmetric with respect to the central axis of the N-well 4, the first N-type doped region 13 and the third N-type doped region 17 are symmetric with respect to the central axis of the N-well 4, and the second P-type doped region 14 and the third P-type doped region 16 are symmetric with respect to the central axis of the N-well 4.

[0065] In this embodiment, the wells and doped regions of the thyristor rectifier 100 are symmetrically distributed, its forward SCR loop SCR1 and reverse SCR loop SCR2 physically overlap, the ports of the integrated circuit can work in the forward SCR loop or the reverse SCR loop, and the overall device structure is axially symmetric with respect to the central straight line, and the physical layout is more compact.

[0066] In some embodiments, when looking from the first P-well 3, through the N-well 4, towards the second P-well 5, the doped regions are in sequence the first P-type doped region 12, the first N-type doped region 13, the second P-type doped region 14, the second N-type doped region 15, the third P-type doped region 16, the third N-type doped region 17, and the fourth P-type doped region 18.

[0067] In some embodiments, a deep N-well 42 is formed in the substrate, and the first P-well 3, the N-well 4, and the second P-well 5 are disposed on the upper surface of the deep N-well 42.

[0068] In some embodiments, a shallow trench isolation structure is formed between adjacent doped regions, and the depth of each doped region is less than the depth of the shallow trench isolation structure.

[0069] Specifically, a first trench 6 is provided between the first P-type doped region 12 and the first N-type doped region 13, a second trench 7 is provided between the first N-type doped region 13 and the second P-type doped region 14, a third trench 8 is provided between the second P-type doped region 14 and the second N-type doped region 15, a fourth trench 9 is provided between the second N-type doped region 15 and the third P-type doped region 16, a fifth trench 10 is provided between the third P-type doped region 16 and the third N-type doped region 17, and a sixth trench 11 is provided between the third N-type doped region 17 and the fourth P-type doped region 18. All the trenches are shallow trenches.

[0070] In some embodiments, the number of diodes in the diode string 200 is greater than or equal to 0.

[0071] In some embodiments, the diode string 200 includes a fifth diode 201 and a sixth diode 202;

[0072] The positive electrode of the fifth diode 201 is the positive electrode of the diode string 200, the negative electrode of the fifth diode 201 is connected to the positive electrode of the sixth diode 202, and the negative electrode of the sixth diode 202 is the negative electrode of the diode string 200.

[0073] Figure 2 It is an equivalent circuit diagram of a thyristor device provided by an embodiment of the present application.

[0074] As Figure 2 shown, correspondingly, an embodiment of the present application further provides a diode-triggered circuit, including:

[0075] A forward diode trigger circuit, which includes a first diode 105, a diode string 200, and a second diode 106;

[0076] A reverse diode trigger circuit, which includes a third diode 107, a diode string 200, and a fourth diode 108;

[0077] A forward SCR loop, which includes a first PNP bipolar transistor 101 and the first NPN bipolar transistor 103;

[0078] A reverse SCR loop, which includes a second PNP bipolar transistor 102 and a second NPN bipolar transistor 104;

[0079] The forward diode triggering circuit and the reverse diode triggering circuit share the diode string 200.

[0080] In some embodiments, the positive electrode of the first diode 105 is connected to the anode A, the negative electrode of the first diode 105 is connected to the positive electrode of the diode string 200, the negative electrode of the diode string 200 is connected to the positive electrode of the second diode 106, and the negative electrode of the second diode 106 is connected to the cathode D; starting from the anode A, passing through the first diode 105, the diode string 200, and the second diode 106 to reach the cathode D, the forward diode triggering circuit is formed.

[0081] In some embodiments, the positive electrode of the third diode 107 is connected to the cathode D, the negative electrode of the third diode 107 is connected to the positive electrode of the diode string 200, the negative electrode of the diode string 200 is connected to the positive electrode of the fourth diode 108, and the negative electrode of the fourth diode 108 is connected to the anode A; starting from the cathode D, passing through the third diode 107, the diode string 200, and the fourth diode 108 to reach the anode A, the reverse diode triggering circuit is formed.

[0082] In some embodiments, the base of the first PNP bipolar transistor 101 is the collector of the first NPN bipolar transistor 103, the base of the first NPN bipolar transistor 103 is the collector of the first PNP bipolar transistor 101, the base of the first PNP bipolar transistor 101 is connected to the positive electrode of the diode string 200, the collector of the first PNP bipolar transistor 101 is connected to the negative electrode of the diode string 200, the emitter of the first PNP bipolar transistor 101 is connected to the anode A, and the emitter of the first NPN bipolar transistor 103 is connected to the cathode D; starting from the anode A, passing through the first PNP bipolar transistor 101 and the first NPN bipolar transistor 103 to reach the cathode D, the forward SCR circuit is formed.

[0083] In some embodiments, the base of the second PNP bipolar transistor 102 is the collector of the second NPN bipolar transistor 104, the base of the second NPN bipolar transistor 104 is the collector of the second PNP bipolar transistor 102, the base of the second PNP bipolar transistor 102 is connected to the positive electrode of the diode string 200, the collector of the second PNP bipolar transistor 102 is connected to the negative electrode of the diode string 200, the emitter of the second NPN bipolar transistor 104 is connected to the anode A, and the emitter of the second PNP bipolar transistor 102 is connected to the cathode D; starting from the cathode D, passing through the second PNP bipolar transistor 102 and the second NPN bipolar transistor 104 to reach the anode A, the reverse SCR circuit is formed.

[0084] In some embodiments, the number of diodes in the diode string 200 is greater than or equal to 0.

[0085] In some embodiments, the diode string 200 includes a fifth diode 201 and a sixth diode 202;

[0086] The positive electrode of the fifth diode 201 is the positive electrode of the diode string 200. The negative electrode of the fifth diode 201 is connected to the positive electrode of the sixth diode 202. The negative electrode of the sixth diode 202 is the negative electrode of the diode string 200.

[0087] Correspondingly, an embodiment of the present application further provides an integrated circuit triggered by a diode, including the circuit triggered by a diode as described above.

[0088] The circuit triggered by a diode and the integrated circuit provided in this embodiment have the same beneficial effects as the thyristor device triggered by the foregoing diode, which will not be elaborated here.

[0089] Those of ordinary skill in the art can understand that the above embodiments are specific embodiments for implementing the present application. In actual applications, various changes can be made in form and details without departing from the spirit and scope of the present application. Any person skilled in the art can make respective changes and modifications without departing from the spirit and scope of the present application. Therefore, the protection scope of the present application should be subject to the scope defined by the claims.

Claims

1. A diode-triggered triac device, characterized in that, It includes a thyristor rectifier and a diode string. The thyristor rectifier has an anode and a cathode and includes: a P-type substrate; a first P-well formed within the P-type substrate, in which a first P-type doped region and a first N-type doped region are formed; a second P-well formed within the P-type substrate, in which a third N-type doped region and a fourth P-type doped region are formed; an N-well formed within the P-type substrate, in which a second P-type doped region, a second N-type doped region and a third P-type doped region are formed; wherein, the first N-type doped region, the third P-type doped region are electrically connected to the anode; the third N-type doped region, the second P-type doped region are electrically connected to the cathode; the second N-type doped region is electrically connected to the positive electrode of the diode string, and the first P-type doped region and the fourth P-type doped region are electrically connected to the negative electrode of the diode string.

2. The diode-triggered triac device according to claim 1, characterized in that, The first P-type doped region, the second P-type doped region, the third P-type doped region, the fourth P-type doped region, the first N-type doped region, the second N-type doped region and the third N-type doped region are all heavily doped regions, and the first P-well, the second P-well and the N-well are all lightly doped regions.

3. The diode-triggered triac device according to claim 1, characterized in that, The first P-well and the second P-well are adjacent to the N-well, and the first P-well and the second P-well are symmetrically distributed with respect to the central axis of the N-well; wherein, the first P-type doped region and the fourth P-type doped region are symmetric with respect to the central axis of the N-well, the first N-type doped region and the third N-type doped region are symmetric with respect to the central axis of the N-well, and the second P-type doped region and the third P-type doped region are symmetric with respect to the central axis of the N-well.

4. The diode-triggered triac device according to claim 3, wherein Looking from the direction of the first P-well, through the N-well to the second P-well, the doped regions are in sequence the first P-type doped region, the first N-type doped region, the second P-type doped region, the second N-type doped region, the third P-type doped region, the third N-type doped region and the fourth P-type doped region.

5. The diode-triggered triac device according to claim 1, characterized in that, A deep N-well is formed within the substrate, and the first P-well, the N-well and the second P-well are disposed on the upper surface of the deep N-well.

6. The diode-triggered triac device according to claim 1, characterized in that, Shallow trench isolation structures are formed between adjacent doped regions, and the depth of the doped regions is less than the depth of the shallow trench isolation structures.

7. The diode-triggered triac device according to claim 1, characterized in that, The number of diodes in the diode string is greater than or equal to 0.

8. The diode-triggered triac device according to claim 7, wherein The diode string includes a fifth diode and a sixth diode; The positive electrode of the fifth diode is the positive electrode of the diode string, the negative electrode of the fifth diode is connected to the positive electrode of the sixth diode, and the negative electrode of the sixth diode is the negative electrode of the diode string.

9. A diode-triggered circuit, characterized in that, It includes: a forward diode trigger circuit, the forward diode trigger circuit includes a first diode, a diode string and a second diode; a reverse diode trigger circuit, the reverse diode trigger circuit includes a third diode, a diode string and a fourth diode; a forward SCR circuit, the forward SCR circuit includes a first PNP bipolar transistor and a first NPN bipolar transistor; a reverse SCR circuit, the reverse SCR circuit includes a second PNP bipolar transistor and a second NPN bipolar transistor; The forward diode trigger circuit and the reverse diode trigger circuit share the diode string.

10. A diode-triggered circuit according to claim 9, wherein the anode of the first diode is connected to the anode, the cathode of the first diode is connected to the anode of the diode string, the cathode of the diode string is connected to the anode of the second diode, and the cathode of the second diode is connected to the cathode; starting from the anode, passing through the first diode, the diode string, and the second diode to reach the cathode, a forward diode trigger circuit is formed.

11. A diode-triggered circuit according to claim 9, wherein the cathode of the third diode is connected to the cathode, the anode of the third diode is connected to the anode of the diode string, the cathode of the diode string is connected to the anode of the fourth diode, and the cathode of the fourth diode is connected to the anode; starting from the cathode, passing through the third diode, the diode string, and the fourth diode to reach the anode, a reverse diode trigger circuit is formed.

12. A diode-triggered circuit according to claim 9, wherein the base of the first PNP bipolar transistor is the collector of the first NPN bipolar transistor, the base of the first NPN bipolar transistor is the collector of the first PNP bipolar transistor, the base of the first PNP bipolar transistor is connected to the anode of the diode string, the collector of the first PNP bipolar transistor is connected to the cathode of the diode string, the emitter of the first PNP bipolar transistor is connected to the anode, and the emitter of the first NPN bipolar transistor is connected to the cathode; starting from the anode, passing through the first PNP bipolar transistor and the first NPN bipolar transistor to reach the cathode, a forward SCR circuit is formed.

13. A diode-triggered circuit according to claim 9, wherein the base of the second PNP bipolar transistor is the collector of the second NPN bipolar transistor, the base of the second NPN bipolar transistor is the collector of the second PNP bipolar transistor, the base of the second PNP bipolar transistor is connected to the anode of the diode string, the collector of the second PNP bipolar transistor is connected to the cathode of the diode string, the emitter of the second NPN bipolar transistor is connected to the anode, and the emitter of the second PNP bipolar transistor is connected to the cathode; starting from the cathode, passing through the second PNP bipolar transistor and the second NPN bipolar transistor to reach the anode, a reverse SCR circuit is formed.

14. The diode-triggered circuit according to any one of claims 9-13, characterized in that, The number of diodes in the diode string is greater than or equal to 0.

15. The diode-triggered circuit according to claim 14, wherein, The diode string includes a fifth diode and a sixth diode; The anode of the fifth diode is the anode of the diode string, the cathode of the fifth diode is connected to the anode of the sixth diode, and the cathode of the sixth diode is the cathode of the diode string.

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