Temperature detection system for p-type gate gallium nitride power device

Abstract

The invention provides a temperature detection system for a p-type grid gallium nitride power device. The temperature detection system comprises a power element, a gallium nitride grid grounding transistor unit and a temperature detection unit. The power element can generate heat during working; the gallium nitride grid grounding transistor unit comprises at least one gallium nitride grid grounding transistor; and the temperature detection unit can measure a first parameter of the gallium nitride grid grounding transistor unit and determine the temperature of the gallium nitride power device according to the first parameter. According to the scheme, high voltage is not switched on or off, the influence of a trap state is avoided, and the precision, the sensitivity, the linearity and the repeatability are high. The gallium nitride grid grounding transistor is completely compatible with a power element technology, integration on the same chip can be achieved, extra PCB packaging integration is not needed, and cost is reduced. And the gallium nitride grid grounding transistor is positioned in the gallium nitride power device, so that the temperature detection precision is higher.

Description

Technical Field

[0001] The present application relates to a temperature detection system for electronic components, and in particular to a temperature detection system for p-type gate gallium nitride power devices. Background Art

[0002] Gallium nitride is a new wide bandgap semiconductor material with extremely excellent material properties, including high breakdown field strength, high electron mobility and saturated electron drift rate. Compared with traditional silicon metal oxide semiconductor field effect transistors and insulated gate bipolar transistors, the size of gallium nitride power devices is much smaller than that of silicon devices with the same on-resistance, and power semiconductor devices based on gallium nitride can achieve higher power density and efficiency, which can reduce the power consumption of power converters by 80% and obtain smaller system dimensions.

[0003] When the internal temperature of a power device rises above a certain level, the relevant parameters / performance of the power device will be significantly degraded. Therefore, temperature measurement is an important issue for power devices. Based on the characteristics of GaN materials and devices, a new integrated on-chip temperature detector has been developed. This type of detector can be placed inside a GaN power device to more accurately monitor the temperature inside the power device. However, these new technologies have great performance limitations, poor accuracy or linearity, and are incompatible with existing mainstream production processes, making it difficult to achieve practical applications.

[0004] The first existing method for detecting GaN power devices is to directly use the on-resistance set inside the GaN power device as a temperature detector for temperature detection. The process is compatible and can be integrated, and the cost is low. However, because the power device needs to switch high voltage (GaN power devices are usually used under high voltage conditions, they need to switch high voltage. Specifically, the GaN power device is connected between the ground wire and the high voltage bus, and is part of the power circuit. The power conversion is achieved by switching high voltage. This solution uses the characteristics of the GaN device itself for temperature detection, that is, the temperature detector itself is located in the high-voltage power circuit, so it is affected by the switching high voltage, that is, the switching high voltage), it will be affected by the trap state, resulting in extremely poor sensitivity, accuracy, linearity, and repeatability of temperature detection; it is impossible to monitor the device temperature in real time when the device is in working condition.

[0005] The second existing method for detecting GaN power devices is to use a separate silicon-based device or circuit outside the GaN power device for temperature detection. The silicon process of this solution is mature, and high voltage is not switched (this solution uses a silicon-based device or circuit outside the GaN power device as a temperature detector. The temperature detector is set in the ground wire and the low-voltage control loop to achieve temperature detection and control. It is not in the high-voltage power loop and does not participate in the switching of high voltage. Therefore, it is not affected by the switching high voltage of the detection body, that is, it does not switch high voltage). However, the separate silicon-based device or circuit outside the GaN power device cannot be integrated on a single chip, and needs to be packaged and integrated, and the package integration or circuit board PCB integration requires additional costs; and because the temperature detector is located outside the GaN power device, it is very far away from the GaN power device and cannot detect the hot spot temperature inside the GaN power device.

[0006] The third existing method for detecting GaN power devices is to use a GaN Schottky diode installed inside the GaN power device as a temperature detector for temperature detection without switching high voltage. However, the GaN Schottky diode process is incompatible with the existing GaN power device process and cannot be integrated; GaN Schottky diodes have basic performance and reliability defects and cannot be commercialized for a long time; and the detection sensitivity and accuracy are low.

[0007] The fourth existing method for detecting GaN power devices is to use a GaN PN diode or a GaN PN diode series resistor set inside the GaN power device as a temperature detector for temperature detection. The sensitivity is higher when the high voltage is not switched and the series resistor is connected. However, the current needs to pass through p-type GaN, and the GaN p-type layer is full of trap states due to material limitations. Therefore, the repeatability and reliability of the device are poor, and the sensitivity, linearity and accuracy are poor. In addition, an ohmic contact needs to be formed between the P-type layer and the metal, which is incompatible with the mainstream process of existing GaN power devices.

[0008] In view of this, a reliable solution for detecting the temperature of GaN power devices is urgently needed. Summary of the invention

[0009] According to one aspect of the present application, a temperature detection system for a p-type gate gallium nitride power device is provided, comprising: a power element capable of generating heat during operation; A gallium nitride gate grounded transistor unit, comprising at least one gallium nitride gate grounded transistor; and A temperature detection unit is configured to measure a first parameter of the GaN gate grounded transistor unit and determine a temperature of the GaN power device according to the first parameter.

[0010] In one embodiment, the GaN gate grounded transistor unit includes a plurality of GaN gate grounded transistors, and the plurality of GaN gate grounded transistors are connected in series.

[0011] In one embodiment, the first parameter includes a forward conduction voltage, wherein: Determining the temperature of the gallium nitride power device according to the first parameter includes: The temperature of the gallium nitride power device is calculated according to a first predetermined relationship between the temperature and the forward conduction voltage of the gallium nitride gate grounded transistor unit.

[0012] In one embodiment, the first parameter includes on-resistance, wherein, Determining the temperature of the gallium nitride power device according to the first parameter includes: The on-resistance of the gallium nitride gate-grounded transistor unit is calculated according to the forward conduction voltage and the corresponding on-current of the gallium nitride gate-grounded transistor unit, and the temperature of the gallium nitride power device is calculated according to a second predetermined relationship between the temperature and the on-resistance of the gallium nitride gate-grounded transistor unit.

[0013] In one embodiment, an anode of a first GaN gate-grounded transistor among the at least one GaN gate-grounded transistor is connected to the power element, and a cathode of a last GaN gate-grounded transistor among the at least one GaN gate-grounded transistor is connected to the temperature detection unit, so that the temperature detection unit measures the first parameter of the GaN gate-grounded transistor unit.

[0014] In one embodiment, the temperature detection system further includes: An internal control circuit is connected to the GaN gate-grounded transistor unit and the temperature detection unit respectively, so that the internal control circuit controls, drives and / or protects the GaN gate-grounded transistor unit.

[0015] In one embodiment, the internal control circuit is also connected to the power element.

[0016] In one embodiment, the temperature detection system further includes: An internal protection circuit is provided, wherein the internal protection circuit and the GaN gate grounding transistor unit share at least one GaN gate grounding transistor.

[0017] In one embodiment, the temperature detection system further includes: a resistor, wherein the resistor is connected in series with the GaN gate grounded transistor.

[0018] In one embodiment, the temperature detection system further includes: An internal control circuit is connected to the GaN gate-grounded transistor unit and the temperature detection unit respectively, so that the internal control circuit controls, drives and / or protects the GaN gate-grounded transistor unit.

[0019] In one embodiment, the internal control circuit is also connected to the power element.

[0020] The embodiments described in this application have the following beneficial effects: The temperature detection system provided by the present application uses the first parameters of the GaN gate grounded transistor integrated with the power element (such as the forward conduction voltage, conduction current, conduction resistance, etc. of the GaN gate grounded transistor unit or the GaN gate grounded transistor) for temperature detection. It does not switch high voltages, is not affected by trap states, and has high accuracy, high sensitivity, high linearity, and high repeatability. The GaN gate grounded transistor is fully compatible with the power element process and can be integrated on the same chip to obtain a GaN power device. No additional PCB packaging integration is required, which reduces costs; and the GaN gate grounded transistor is located inside the GaN power device, and the temperature detection accuracy is higher. The GaN gate grounded transistor unit provided by the present application is fully compatible with the P-type Schottky process of existing GaN power devices, and has been batch verified and commercialized on a large scale, with low integration difficulty and low cost. Based on the principle of positive temperature coefficient, parasitic resistance will enhance the performance of the device, and the detection sensitivity and accuracy are high. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solution of the embodiment of the present application, the following briefly introduces the drawings required for the description of the embodiment. The drawings described below are only exemplary embodiments of the present application.

[0022] Figure 1 A schematic structural diagram of a first embodiment of a temperature detection system of the present application is shown; Figure 2 A schematic diagram showing the structure of a second embodiment of the temperature detection system of the present application is shown; Figure 3 A schematic diagram showing the structure of a third embodiment of the temperature detection system of the present application is shown; Figure 4 A schematic structural diagram of a fourth embodiment of the temperature detection system of the present application is shown; Figure 5 A schematic diagram showing the structure of a fifth embodiment of the temperature detection system of the present application is shown; Figure 6 A schematic structural diagram of a sixth embodiment of the temperature detection system of the present application is shown; Figure 7 A schematic diagram showing the structure of a seventh embodiment of the temperature detection system of the present application is shown; Figure 8 A schematic diagram of the structure of a GaN gate grounded transistor is shown; Fig. 9 is a schematic diagram showing the relationship between temperature and forward voltage. DETAILED DESCRIPTION

[0023] The exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present application and to enable the scope of the present application to be fully communicated to those skilled in the art. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concepts of the present application.

[0024] Various structural schematic diagrams according to embodiments of the present application are shown in the accompanying drawings. These figures are not drawn to scale, and some details are magnified and some details may be omitted for the purpose of clear expression. The shapes of various regions and layers shown in the figures and the relative sizes and positional relationships therebetween are only exemplary, and may deviate in practice due to manufacturing tolerances or technical limitations, and those skilled in the art may further design regions / layers with different shapes, sizes, and relative positions according to actual needs.

[0025] The GaN gate grounded transistor is a device implemented based on the existing mainstream p-type GaN Schottky contact process. There is no Schottky contact inside the device, and current does not pass through the p-type GaN. After shorting the source and gate of the GaN power transistor, the equivalent circuit diagram of the GaN gate grounded transistor is obtained. The GaN gate grounded transistor is based on the GaN power device process and has full process compatibility and integration capabilities.

[0026] In view of this, the present application uses a gallium nitride gate grounded transistor to achieve temperature detection. Specifically, the present application provides a temperature detection system for a p-type gate gallium nitride power device, including: a power element, a gallium nitride gate grounded transistor and a temperature detection unit. The power element can generate heat during operation; the gallium nitride gate grounded transistor unit includes at least one gallium nitride gate grounded transistor; the temperature detection unit can measure a first parameter of the gallium nitride gate grounded transistor, and determine the temperature of the p-type gate gallium nitride power device based on the first parameter.

[0027] The embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0028] See also Figure 1 , Figure 1The schematic diagram of the structure of the first embodiment of the temperature detection system of the present application is shown. The temperature detection system 10 includes a power element 11, a gallium nitride gate grounded transistor unit 12 and a temperature detection unit 13.

[0029] The power element 11 is a gallium nitride power element, such as a gallium nitride high electron mobility transistor (GaNHEMT), a gallium nitride field effect transistor (GaN FET), a gallium nitride decision maker, a gallium nitride integrated circuit, etc.

[0030] GaN power components can generate heat during operation. For example, when a GaN power component is in the on state, although its on resistance is low, a certain amount of current will still flow through it, thereby generating heat. For another example, during the switching process, the GaN power component needs to undergo a state transition from on to off. During this process, due to the simultaneous presence of voltage and current, energy is lost and converted into heat. As the GaN power component heats up, the temperature of the GaN power device rises. If the temperature of the GaN power device is too high, it will affect the performance of the GaN power device. Therefore, it is necessary to monitor the temperature of the GaN power.

[0031] like Figure 1 As shown in , the temperature detection system 10 also includes a gallium nitride gate grounded transistor unit 12 and a temperature detection unit 13. The power element 11 and the gallium nitride gate grounded transistor unit 12 are jointly arranged on a p-type gate gallium nitride power device (or a p-type gate gallium nitride chip). In addition to the power element 11 and the gallium nitride gate grounded transistor unit 12, the p-type gate gallium nitride power device may also include other elements, such as an internal control circuit, a drive circuit, etc., which will be described in detail below. In the following, if there is no additional explanation, the terms "p-type gate gallium nitride power device" and "gallium nitride power device" have the same meaning.

[0032] The temperature detection unit 13 can measure the first parameter of the GaN gate grounded transistor unit 12, and determine the temperature of the p-type gate GaN power device according to the first parameter. The first parameter can be the forward conduction voltage of the GaN gate grounded transistor, or it can be the forward conduction resistance or the forward conduction current. There is a specific relationship between the forward conduction voltage, the forward conduction resistance, and the forward conduction current and the temperature of the GaN power device, so by measuring one or more of the forward conduction voltage, the forward conduction resistance, and the forward conduction current, the temperature of the GaN power device can be calculated. The following will also describe in detail the relationship between the forward conduction voltage, the forward conduction resistance, and the forward conduction current and the temperature of the GaN power device in combination with specific embodiments.

[0033] Specifically, the temperature detection of the GaN power device described in the present application is realized based on some characteristics of the GaN gate grounded transistor and the change of electrical characteristics after series connection. Specifically, as the temperature of the GaN power device increases, the mobility of the electrons in the conductive channel of the GaN gate grounded transistor decreases, causing the on-resistance of the GaN gate grounded transistor to increase. Under the condition of constant current source input, it is manifested as the forward conduction voltage (VON) of the GaN gate grounded transistor increases, and presents a relatively stable change law, that is, the linearity between temperature and forward conduction voltage VON is high. By connecting multiple GaN gate grounded transistors in series, the influence of temperature changes on circuit voltage can be enhanced, thereby improving the sensitivity of temperature detection. Further, when the temperature changes, the total voltage of the GaN gate grounded transistor unit 12 will change accordingly. By measuring the voltage value at a specific point in the circuit and comparing it with the reference voltage, the temperature can be calculated based on the linear relationship between temperature and forward conduction voltage VON described above.

[0034] Fig. 9 The relationship between temperature and forward conduction voltage VON is shown. Fig. 9 As shown in the figure, the horizontal axis represents temperature (Temperature), the vertical axis represents the forward conduction voltage VON, and there is a linear relationship between temperature and forward conduction power.

[0035] Based on the above principle, when the forward conduction voltage of the GaN gate-grounded transistor unit 12 is measured by the temperature detection unit 13, the temperature of the GaN power device can be calculated according to the first predetermined relationship between the temperature and the forward conduction voltage of the GaN gate-grounded transistor unit 12.

[0036] It should be noted that the first predetermined relationship may be the relationship between the temperature and the forward conduction voltage of the GaN gate grounded transistor unit 12 (i.e., the total voltage when all the GaN gate grounded transistors connected in series are turned on); the first predetermined relationship may also be the relationship between the temperature and the forward conduction voltage of a certain GaN gate grounded transistor in the GaN gate grounded transistor unit 12. In other words, in one embodiment, the forward conduction voltage refers to the voltage of the GaN gate grounded transistor unit 12 when it is forward-conducted, i.e., the temperature detection unit 13 may measure the total voltage when all the GaN gate grounded transistors connected in series in the GaN gate grounded transistor unit 12 are turned on, and calculate the temperature of the GaN power device according to the relationship between the voltage and the temperature; in another embodiment, the forward conduction voltage refers to the voltage of a certain GaN gate grounded transistor in the GaN gate grounded transistor unit 12 when it is forward-conducted, i.e., the temperature detection unit 13 may measure the forward conduction voltage when a certain GaN gate grounded transistor in the GaN gate grounded transistor unit 12 is turned on, and calculate the temperature of the GaN power device according to the relationship between the voltage and the temperature. In the present application, if not otherwise specified, the term “forward conduction voltage” refers to the voltage of the GaN gate grounded transistor unit 12 when it is forward-conducting.

[0037] It should be noted that, since there is a certain relationship between voltage, resistance and current, the above description is to determine the temperature of the gallium nitride power device according to the first predetermined relationship between temperature and forward conduction voltage. In other embodiments, the current or resistance corresponding to the gallium nitride gate grounded transistor unit 12 when forward conducting can also be detected, and then the temperature of the gallium nitride power device is calculated based on the predetermined relationship between the current or the resistance and the temperature. This will be described in detail below in conjunction with specific embodiments.

[0038] The GaN gate grounded transistor unit 12 includes at least one GaN gate grounded transistor. In one embodiment, the GaN gate grounded transistor unit 12 may include one GaN gate grounded transistor. In another embodiment, the GaN gate grounded transistor unit 12 may include a plurality of (e.g., 2, 3, 4, etc.) GaN gate grounded transistors. When the GaN gate grounded transistor unit 12 includes a plurality of GaN gate grounded transistors, the plurality of GaN gate grounded transistors are connected in series.

[0039] This application Figure 1 The GaN gate grounded transistor unit 12 is described by taking three GaN gate grounded transistors connected in series as an example. Figure 1 As shown, three GaN gate grounded transistors are sequentially connected in series to form a GaN gate grounded transistor unit 12 .

[0040] In one embodiment, an anode of a first GaN gate-grounded transistor among the at least one GaN gate-grounded transistor is connected to the power element, and a cathode of a last GaN gate-grounded transistor among the at least one GaN gate-grounded transistor is connected to the temperature detection unit, so that the temperature detection unit measures the first parameter of the GaN gate-grounded transistor unit.

[0041] like Figure 1 As shown in , the source of the power element 11 is connected to the anode of the first GaN gate grounded transistor (i.e., the leftmost GaN gate grounded transistor) among the three GaN gate grounded transistors connected in series, and the anode of the first GaN gate grounded transistor can be connected to a peripheral circuit (e.g., connected to a temperature detection unit 13 in the peripheral circuit), the drain of the power element 11 is connected to the peripheral circuit, and the gate of the power element 11 is connected to the peripheral circuit. The cathode of the last GaN gate grounded transistor (i.e., the rightmost GaN gate grounded transistor) among the three GaN gate grounded transistors connected in series is connected to the temperature detection unit 13, so that the temperature detection unit 13 measures the first parameter of the GaN gate grounded transistor unit 12.

[0042] In one embodiment, the temperature detection unit 13 is capable of measuring a first parameter of the GaN gate grounded transistor unit 12, and the first parameter is a forward conduction voltage. The temperature detection unit 13 determines the temperature of the GaN power device according to the first parameter, specifically comprising: calculating the temperature of the GaN power device according to a first predetermined relationship between the temperature and the forward conduction voltage of the GaN gate grounded transistor unit 12. The forward conduction voltage of the GaN gate grounded transistor unit 12 is a voltage between an anode of a first GaN gate grounded transistor and a cathode of a last GaN gate grounded transistor in the GaN gate grounded transistor unit 12.

[0043] In another embodiment of the present application, the temperature detection unit 13 can measure a first parameter of the GaN gate grounded transistor unit 12, the first parameter including an on-resistance, and the temperature detection unit 13 calculates the on-resistance of the GaN gate grounded transistor unit according to the forward conduction voltage and the corresponding on-current of the GaN gate grounded transistor unit, and calculates the temperature of the GaN power device according to a second predetermined relationship between temperature and the on-resistance of the GaN gate grounded transistor unit. The on-resistance of the GaN gate grounded transistor unit 12 is the resistance between the anode of the first GaN gate grounded transistor and the cathode of the last GaN gate grounded transistor in the GaN gate grounded transistor unit 12. In this embodiment, the second predetermined relationship between temperature and the on-resistance of the GaN gate grounded transistor unit can be calculated in advance. Therefore, when the temperature detection unit 13 measures the on-resistance of the GaN gate grounded transistor unit, the temperature of the GaN power device can be determined according to the second predetermined relationship.

[0044] In this embodiment, if Figure 1 As shown, the temperature detection unit 13 may be disposed outside the GaN power device, for example, the temperature detection unit 13 may be disposed in a peripheral circuit. In another embodiment, the temperature detection unit 13 may be disposed inside the GaN power device.

[0045] It should be noted that, in the present application, the power element 11 and the gallium nitride gate-grounded transistor unit 12 are both connected to the peripheral circuit and are powered and controlled by the peripheral circuit. However, the power element 11 and the gallium nitride gate-grounded transistor unit 12 are respectively in different power supply circuits, that is, the peripheral circuit includes at least two power supply circuits, one of which is used to power the power element 11 and control the power element 11, and the other is used to power the gallium nitride gate-grounded transistor unit 12 and control the gallium nitride gate-grounded transistor unit 12.

[0046] Refer to the following Figure 2 A second embodiment of the temperature detection system of the present application is described. Figure 2 FIG. 2 shows a schematic diagram of the structure of the second embodiment of the temperature detection system of the present application. Figure 1 Compared with the embodiment shown in FIG. 1 , this embodiment further includes an internal control circuit 14, which is connected to the GaN gate grounded transistor unit and the temperature detection unit, respectively, so that the internal control circuit 14 controls, drives and / or protects the GaN gate grounded transistor unit. In this embodiment, the internal control circuit 14 is arranged in the GaN power device. The arrangement, implementation method and temperature detection principle of the power element 11, the GaN gate grounded transistor unit 12, the temperature detection unit 13, etc. are the same or similar to those of the embodiment described above, and will not be repeated here.

[0047] In one embodiment, the internal control circuit 14 can perform signal processing, control, comparison, filtering, noise reduction and other processing, and the internal control circuit 14 can be integrated in a single chip or in a package.

[0048] Refer to the following Figure 3 A third embodiment of the temperature detection system of the present application is described. Figure 3 FIG. 2 shows a schematic diagram of the structure of the third embodiment of the temperature detection system of the present application. Figure 1 and Figure 2 In the embodiment shown, the gate of the power element 11 is connected to the peripheral circuit, that is, the gate drive signal of the power element 11 is provided by the peripheral circuit outside the packaged chip or wafer. Figure 3 The embodiment shown is Figure 1 and Figure 2 The difference of the embodiment shown is that the power element 11 is connected to the internal control circuit 14. Specifically, the gate of the power element 11 is connected to the internal control circuit 14 arranged in the gallium nitride power device, that is, the gate drive signal of the power element 11 is provided by the internal control circuit 14 in the packaged chip or wafer. The arrangement, implementation method and temperature detection principle of the power element 11, the gallium nitride gate grounded transistor unit 12, the temperature detection unit 13, etc. are the same as those in the above reference. Figure 1 The described embodiments are the same or similar and will not be described in detail here.

[0049] Refer to the following Figure 4 A fourth embodiment of the temperature detection system of the present application is described. Figure 4 FIG. 4 is a schematic diagram showing the structure of the fourth embodiment of the temperature detection system of the present application. Figure 4 In the illustrated embodiment, the temperature detection system further includes an internal protection circuit 15, which shares at least one GaN gate grounding transistor with the GaN gate grounding transistor unit 12. The internal protection circuit 15 can be used for ESD protection or rectification, and is mainly used to protect the chip port from electrostatic damage.

[0050] Specifically, in this embodiment, the gate of the power element 11 is connected to the peripheral circuit. One end of the internal protection circuit 15 is connected to the source of the power element 11, and the other end is connected to the gate of the power element 11. The two ends of the GaN gate grounded transistor unit 12 are respectively connected to the peripheral circuit. The configuration, implementation method and temperature detection principle of the power element 11, the GaN gate grounded transistor unit 12, the temperature detection unit 13, etc. are the same or similar to those of the above-described embodiments, and will not be repeated here.

[0051] like Figure 4As shown in , the internal protection circuit 15 may include a resistor R, a gallium nitride gate grounding transistor M and a transistor T in addition to the gallium nitride gate grounding transistor shared with the gallium nitride gate grounding transistor unit 12. The resistor R is connected in series with the gallium nitride gate grounding transistor in the gallium nitride gate grounding transistor unit 12. The gallium nitride gate grounding transistor M is connected in series with the gallium nitride gate grounding transistor in the gallium nitride gate grounding transistor unit 12 and connected to the gate of the power element 11. The first channel end of the transistor T is connected to the source of the power element 11, the second channel end of the transistor T is connected to the gate of the power element 11, and the control end of the transistor T is connected to the node between the resistor R and the gallium nitride gate grounding transistor unit 12 and connected to the peripheral circuit, or connected to the temperature detection unit 13 in the peripheral circuit.

[0052] In this embodiment, the internal protection circuit 15 can effectively protect the chip port from electrostatic damage. In addition, the internal protection circuit 15 and the GaN gate grounding transistor unit 12 share at least one GaN gate grounding transistor, which can save chip area and cost.

[0053] Refer to the following Figure 5 A fifth embodiment of the temperature detection system of the present application is described. Figure 5 FIG. 5 is a schematic diagram showing the structure of the fifth embodiment of the temperature detection system of the present application. Figure 4 The difference from the illustrated embodiment is that, in this embodiment, the GaN gate grounded transistor unit 12 further includes a resistor R, which is connected in series with the GaN gate grounded transistor in the GaN gate grounded transistor unit 12 .

[0054] The internal protection circuit 15 shares a GaN gate grounding transistor with the GaN gate grounding transistor unit 12 and also shares a resistor R. The internal protection circuit 15 also includes a GaN gate grounding transistor M and a transistor T. The GaN gate grounding transistor M is connected in series with the GaN gate grounding transistor in the GaN gate grounding transistor unit 12 and is connected to the gate of the power element 11. The first channel end of the transistor T is connected to the source of the power element 11, the second channel end of the transistor T is connected to the gate of the power element 11, and the control end of the transistor T is connected to the node between the resistor R and the GaN gate grounding transistor unit 12. The configuration, implementation method and temperature detection principle of the power element 11, the GaN gate grounding transistor unit 12, the temperature detection unit 13, etc. are the same or similar to those in the above-described embodiment, and are not repeated here.

[0055] Refer to the following Figure 6 A sixth embodiment of the temperature detection system of the present application is described. Figure 6 FIG. 6 is a schematic diagram showing the structure of the sixth embodiment of the temperature detection system of the present application. Figure 4The embodiment shown differs in that Figure 6 The embodiment shown also includes an internal control circuit 14, which is connected to the GaN gate grounded transistor unit 12 and the temperature detection unit 13, respectively, so that the internal control circuit 14 controls, drives and / or protects the GaN gate grounded transistor unit. Figure 2 The internal control circuits in the illustrated embodiments are the same and will not be described in detail here. The configuration, implementation and temperature detection principle of the power element 11, the GaN gate grounded transistor unit 12, the temperature detection unit 13, the internal protection circuit 15, etc. are the same or similar to those in the embodiments described above and will not be described in detail here.

[0056] Refer to the following Figure 7 A seventh embodiment of the temperature detection system of the present application is described. Figure 7 FIG. 7 is a schematic diagram showing the structure of the seventh embodiment of the temperature detection system of the present application. Figure 6 The embodiment shown differs in that Figure 7 In the illustrated embodiment, the power element 11 is connected to the internal control circuit 14. Specifically, the gate of the power element 11 is connected to the internal control circuit 14, that is, the gate drive signal is provided by the internal control circuit 14. The arrangement, implementation and temperature detection principle of the power element 11, the GaN gate grounded transistor unit 12, the temperature detection unit 13, the internal control circuit 14, the internal protection circuit 15, etc. are the same or similar to those in the above-described embodiment, and will not be described in detail here.

[0057] It can be seen from the above embodiments that the temperature detection system provided by the present application does not use the parameters of the power element itself for temperature detection, but uses the first parameters of the GaN gate grounded transistor integrated with the power element (such as the forward conduction voltage, conduction current, conduction resistance, etc. of the GaN gate grounded transistor unit or the GaN gate grounded transistor) for temperature detection. It does not switch high voltages, is not affected by trap states, and has high accuracy, high sensitivity, high linearity, and high repeatability. In addition, the GaN gate grounded transistor unit and the power element are not in the same power supply circuit, so the two can be controlled separately, and the temperature of the GaN power device can be detected in real time.

[0058] In addition, the temperature detection system provided in the present application uses a gallium nitride gate-grounded transistor for temperature detection. The gallium nitride gate-grounded transistor is fully compatible with the power element process and can be integrated on the same chip to obtain a gallium nitride power device. No additional PCB packaging integration is required, which can reduce costs. Moreover, the gallium nitride gate-grounded transistor is located inside the gallium nitride power device, and the temperature detection accuracy is higher.

[0059] In addition, the temperature detection system provided by this application is fully compatible with the P-type Schottky process of existing GaN power devices. This process has been batch verified and commercialized on a large scale, with low integration difficulty and low cost. Based on the principle of positive temperature coefficient, parasitic resistance will enhance the performance of the device, and the detection sensitivity and accuracy are high.

[0060] In addition, the gallium nitride gate grounded transistor provided in the present application, when biased, the electric field is mainly concentrated in the AlGaN (aluminum gallium nitride) / GaN (gallium nitride) heterojunction region ( Figure 8 The blue and purple areas below). The electric field strength in this area is relatively high, which is conducive to the rapid movement of electrons in the two-dimensional electron gas under the action of the electric field, forming the main conductive channel. The current does not pass through P-type gallium nitride and is not affected by the trap state, so the repeatability and reliability are high.

[0061] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0062] Those skilled in the art will appreciate that the modules in the devices in the embodiments may be adaptively changed and arranged in one or more devices different from the embodiments. The modules or units or components in the embodiments may be combined into one module or unit or component, and further may be divided into multiple submodules or subunits or subcomponents. All features disclosed in this specification (including the abstract and drawings) and all processes or units of any method or device disclosed in this manner may be combined in any combination, except that at least some of such features and / or processes or units are mutually exclusive. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying abstract and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

[0063] Furthermore, those skilled in the art will appreciate that although some embodiments herein include certain features included in other embodiments but not other features, the combination of features from different embodiments is meant to be within the scope of the present application and to form different embodiments.

[0064] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0065] It should be noted that the above embodiments illustrate the present application rather than limit the present application. Any reference symbol between brackets should not be constructed as a limitation to the present application. The word "comprising" does not exclude the existence of components or steps not listed in the present application. The word "one" or "an" before a component does not exclude the existence of multiple such components. The present application can be implemented by means of hardware including several different components and by means of a suitably programmed computer. In the embodiment in which several devices are listed, several of these devices can be embodied by the same hardware item. The use of the words first, second, and third, etc. does not indicate any order. These words can be interpreted as names. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise clearly and specifically limited.

[0066] The above is only an exemplary embodiment of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of various changes or substitutions within the technical scope recorded in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be based on the protection scope of the claims.

Claims

1. A temperature detection system for a p-type gate gallium nitride power device, comprising: a power element capable of generating heat during operation; A gallium nitride gate grounded transistor unit, comprising at least one gallium nitride gate grounded transistor; as well as A temperature detection unit is configured to measure a first parameter of the GaN gate grounded transistor unit and determine a temperature of the GaN power device according to the first parameter.

2. The temperature detection system according to claim 1, wherein: The GaN gate grounded transistor unit includes a plurality of GaN gate grounded transistors, and the plurality of GaN gate grounded transistors are connected in series.

3. The temperature detection system according to claim 1 or 2, wherein: The first parameter includes the forward conduction voltage, wherein, Determining the temperature of the gallium nitride power device according to the first parameter includes: The temperature of the gallium nitride power device is calculated according to a first predetermined relationship between the temperature and the forward conduction voltage.

4. The temperature detection system according to claim 1 or 2, wherein: The first parameter includes on-resistance, wherein, Determining the temperature of the gallium nitride power device according to the first parameter includes: The on-resistance of the GaN gate-grounded transistor unit is calculated according to the forward conduction voltage and the corresponding on-current of the GaN gate-grounded transistor unit, and the temperature of the GaN power device is calculated according to a second predetermined relationship between the temperature and the on-resistance of the GaN gate-grounded transistor unit.

5. The temperature detection system according to claim 1, wherein: An anode of a first gallium nitride gate-grounded transistor among the at least one gallium nitride gate-grounded transistor is connected to the power element, and a cathode of a last gallium nitride gate-grounded transistor among the at least one gallium nitride gate-grounded transistor is connected to the temperature detection unit, so that the temperature detection unit measures the first parameter of the gallium nitride gate-grounded transistor unit.

6. The temperature detection system according to claim 1, further comprising: An internal control circuit is connected to the GaN gate-grounded transistor unit and the temperature detection unit respectively, so that the internal control circuit controls, drives and / or protects the GaN gate-grounded transistor unit. 7 . The temperature detection system according to claim 6 , wherein the internal control circuit is further connected to the power element.

8. The temperature detection system according to claim 1, further comprising: An internal protection circuit is provided, wherein the internal protection circuit and the GaN gate grounding transistor unit share at least one GaN gate grounding transistor.

9. The temperature detection system according to claim 8, further comprising: A resistor is connected in series with the GaN gate grounded transistor.

10. The temperature detection system according to claim 9, further comprising: An internal control circuit is connected to the GaN gate-grounded transistor unit and the temperature detection unit respectively, so that the internal control circuit controls, drives and / or protects the GaN gate-grounded transistor unit.

11. The temperature detection system according to claim 10, wherein the internal control circuit is further connected to the power element.

Images