Half-bridge module and switching power supply circuit

Abstract

The present application discloses a half-bridge module and a switching power supply circuit. The half-bridge module comprises an enhancement-mode device serving as a high-side switch and a depletion-mode device serving as a low-side switch; a source of the enhancement-mode device and a drain of the depletion-mode device are electrically connected to from a shared node, wherein the node is used for inputting or outputting power; a drain of the enhancement-mode device serves as a high-voltage terminal of the half-bridge module, and a source of the depletion-mode device serves as a low-voltage terminal of the half-bridge module; a gate of the enhancement-mode device is configured for accessing a high-side switch driving signal, a gate of the depletion-mode device is configured for accessing a low-side switch driving signal, and the enhancement-mode device and the depletion-mode device are configured for complementary switching. According to the half-bridge module provided in the present application, the enhancement-mode device naturally switches off when there is no control signal, thereby providing a built-in safety feature. The low on-resistance and low parasitic capacitance of the depletion-mode device reduce on-state loss and switching loss, and improve overall efficiency.

Description

Half-bridge module and switching power supply circuit

[0001] The application is based on and claims priority to the Chinese patent application No. 202410652625X, filed on May 24, 2024, and entitled "Half-bridge module and switching power supply circuit". TECHNICAL FIELD

[0002] The present application relates to the technical field of semiconductor devices, in particular to a half-bridge module and a switching power supply circuit. BACKGROUND

[0003] The half-bridge module has a wide range of use scenarios. For example, in a switching power supply, a half-bridge circuit often appears in Buck, Boost, FPC, LLC, DAB, etc. After the rise of artificial intelligence, high-energy efficiency step-down circuits play a crucial role in server power supplies. From the perspective of circuit safety, the traditional half-bridge module is shown in FIG. 1, which is usually composed of two normally-off (enhancement mode / E-Mode) devices in cascade, or is integrated or packaged with a driver as shown in FIG. 2, or is integrated with a logic chip, or is cascaded with two CASCODE structure devices as shown in FIG. 3. Due to the parasitic capacitance and on-resistance of the switching devices, the above-mentioned half-bridge module has high switching loss and on-resistance, which makes it difficult to improve the overall efficiency. In the case of high switching frequency and large current, such as server power supply, the efficiency will be significantly reduced.

[0004] Therefore, there is an urgent need for a half-bridge module and a switching power supply circuit to solve the above technical problems.

[0005] SUMMARY

[0006] The present application provides a half-bridge module and a switching power supply circuit, which is used to solve the problem of high switching loss and on-resistance in the related art half-bridge module, which makes it difficult to improve the overall efficiency.

[0007] To achieve the above-mentioned purpose, the present application is realized by the following technical solutions:

[0008] The present application provides a half-bridge module, which includes an enhancement mode device as an upper tube and a depletion mode device as a lower tube;

[0009] The source of the enhancement mode device and the drain of the depletion mode device are electrically connected and form a common node, which is used to access or output power;

[0010] The drain of the enhancement mode device is the high voltage end of the half-bridge module, and the source of the depletion mode device is the low voltage end of the half-bridge module;

[0011] The gate of the enhancement type device is connected to the upper tube driving signal, and the gate of the depletion type device is connected to the lower tube driving signal.

[0012] In one embodiment, the half-bridge module further comprises a functional device, the functional device comprising a driving device and / or a logic device.

[0013] The output of the functional device is electrically connected to the gate of the enhancement type device and the gate of the depletion type device, respectively, so that the gate of the enhancement type device is connected to the upper tube driving signal through the functional device, and the gate of the depletion type device is connected to the lower tube driving signal through the functional device.

[0014] In one embodiment, the enhancement type device comprises any one of a silicon MOSFET, a SiC MOSFET, a pGaN Gate HEMT, and a GaN Trench Gate MIS-HEMT.

[0015] The depletion type device comprises any one of a SiC JFET, a GaN JFET, a GaN MIS-HEMT, and a Ga2O3 MOSFET.

[0016] In one embodiment, the enhancement type device and the depletion type device are packaged together or integrated on the same substrate.

[0017] In one embodiment, the depletion type device is a MIS-HEMT, and the enhancement type device is a pGaN Gate HEMT, and the enhancement type device depletes the two-dimensional electron gas through the pGaN island to achieve a positive threshold.

[0018] In one embodiment, the enhancement type device is an enhancement type high electron mobility transistor with a Trench Gate structure, and the depletion type device is a depletion type high electron mobility transistor with a Metal-Insulator-Semiconductor structure.

[0019] The application also provides a switching power supply circuit, the switching power supply circuit comprising the half-bridge module of any one of the above.

[0020] In one embodiment, the switching power supply circuit is a step-down circuit, and the step-down circuit further comprises a low-voltage side load and a driving module.

[0021] The driving module is configured to generate an upper tube driving signal and a lower tube driving signal and to complementally turn on the upper tube and the lower tube of the half-bridge module, respectively; one end of the low-voltage side load is connected to the node of the half-bridge module, and the other end of the low-voltage side load is connected to the source of the depletion type device of the half-bridge module.

[0022] In one of the embodiments, the depletion-mode device of the half-bridge module comprises a GaN D-Mode MIS-HEMT device.

[0023] In one of the embodiments, the switching power supply circuit further comprises a first capacitor and a first inductor, one end of the low-voltage side load is connected to the node of the half-bridge module through the first inductor, and the first capacitor and the load resistor are connected in parallel.

[0024] Compared with the prior art, the half-bridge module and the switching power supply circuit provided by the application have the following technical advantages:

[0025] The source of the enhancement-mode device is connected to the drain of the depletion-mode device to form a common node, and a switching signal is input. The gate of the enhancement-mode device is connected to an upper tube driving signal, and the gate of the depletion-mode device is connected to a lower tube driving signal. The enhancement-mode device and the depletion-mode device are configured to be complementary conduction, that is, when one device is turned on, the other device is turned off, and vice versa. Since the upper tube is an enhancement-mode device, the circuit is in a safe state without conduction during high-voltage pressurization. Moreover, since the lower tube adopts a depletion-mode device, optimal device performance can be obtained, and the loss is reduced, thereby improving the efficiency of the entire half-bridge module. When the half-bridge module is used in a step-down circuit, the duty cycle of the lower tube is usually high, and part of the loss of the step-down circuit mainly comes from the conduction loss and switching loss of the device. Therefore, when the half-bridge module provided in the embodiment is used in a step-down circuit, the lower tube can provide lower conduction loss, and the performance improvement of the half-bridge module will be more obvious in this case. Thus, the half-bridge module provided by the application does not have the problem of performance limitation that sufficient voltage is needed to maintain the conduction of the depletion-mode device in low-voltage applications. The enhancement-mode device is naturally turned off without a control signal, thereby providing a built-in safety feature. The depletion-mode device can quickly respond to the control signal due to its small parasitic capacitance, thereby reducing the switching loss. At the same time, the small resistance can reduce the conduction loss and improve the overall efficiency. BRIEF DESCRIPTION OF DRAWINGS

[0026] FIGS. 1, 2 and 3 respectively show structure diagrams of three half-bridge modules of the prior art.

[0027] FIGS. 4, 5 and 6 respectively show structure diagrams of three half-bridge modules provided by the embodiments of the application.

[0028] FIG. 7 shows a structure diagram of an implementation method of the half-bridge module provided by the embodiments of the application.

[0029] FIGS. 8, 9 and 10 show structure diagrams of another implementation method of the half-bridge module provided by the embodiments of the application.

[0030] FIG. 11 shows a structure diagram of a switching power supply circuit provided by the embodiments of the application. Detailed Implementation

[0031] To facilitate understanding of this application, a more complete description will be provided below with reference to the accompanying drawings. Preferred embodiments of this application are shown in the drawings. However, this application can be implemented in many other different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of this application.

[0032] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein in the specification of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0033] The following is a brief description of the relevant technologies and terms used in the embodiments of this application.

[0034] In related technologies, wide-bandgap semiconductors, including GaN, AlN, SiC, and gallium oxide, offer superior material properties compared to silicon (e.g., Baliga has high performance indicators), leading to significant advancements in the power supply field. However, some challenges remain in fully leveraging the advantages of these materials in half-bridge modules. For example, manufacturing E-mode devices is difficult, and the performance of E-mode devices is inferior to that of D-mode devices.

[0035] Taking GaN as an example, there are currently two types of devices: D-mode MIS-HEMT and E-mode pGaN Gate HEMT, both of which have been applied to a certain extent in the consumer electronics field. MIS-HEMT devices are manufactured in a process compatible with CMOS, the barrier layer is not dry-etched, and the channel resistance is low, theoretically resulting in lower resistance per unit area. Compared to pGaN Gate HEMT, MIS-HEMT has better gate reliability, higher saturation current density, and is less affected by temperature. Related technologies can be applied to server power supplies using half-bridge low-voltage modules based on pGaN Gate HEMT. Although D-mode GaN MIS-HEMT devices have better performance, they cannot be directly used in half-bridge modules for safety reasons. Using them after passing through a cachede layer will reduce performance, and the cachede layer itself does not offer performance advantages in the low-voltage domain. The cachede structure represents a common-source, common-gate structure.

[0036] MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) refers to a metal oxide semiconductor field effect transistor. JFET refers to a junction field effect transistor (Junction Field-Effect Transistor). HEMT refers to a high electron mobility transistor (High Electron Mobility Transistor). MIS refers to a metal-insulator-semiconductor (Metal Insulator Semiconductor) structure. D-Mode refers to a depletion mode device, and E-Mode refers to an enhancement mode device.

[0037] The application provides a half-bridge module and a switching power supply circuit, focusing on its application in the field of power electronics. By configuring the enhancement mode device as the upper tube and the depletion mode device as the lower tube into a complementary conduction working mode, the problem of high switching loss and conduction loss of the half-bridge module in the related art is solved. The following will first describe the half-bridge module, and then describe the switching power supply circuit.

[0038] Half-bridge module embodiment.

[0039] The half-bridge module provided in the embodiment includes an enhancement mode device as an upper tube and a depletion mode device as a lower tube.

[0040] The source of the enhancement mode device and the drain of the depletion mode device are electrically connected and form a common node, which is used for power input or output.

[0041] The drain of the enhancement mode device is used as the high voltage end of the half-bridge module, and the source of the depletion mode device is used as the low voltage end of the half-bridge module.

[0042] The gate of the enhancement mode device is used to access the upper tube drive signal, and the gate of the depletion mode device is used to access the lower tube drive signal. The enhancement mode device and the depletion mode device are configured to be complementary conduction according to the upper tube drive signal and the lower tube drive signal.

[0043] Referring to FIG. 4, the half-bridge module is composed of two complementary power switching devices. The drain of the enhancement mode device is used as the high voltage end of the half-bridge module and is connected to the high voltage side power supply VDC. The source of the depletion mode device is used as the low voltage end of the half-bridge module, which can be a ground end GND.

[0044] The source of the enhancement mode device is connected to the drain of the depletion mode device to form a common node, which is connected to a switch signal SW (for example, a load or a power supply). The gate GH of the enhancement mode device is connected to an upper tube driving signal, and the gate GL of the depletion mode device is connected to a lower tube driving signal. The control signal can be generated by a PWM controller of a switching power supply, for accurately controlling the switching time and sequence of the devices. The enhancement mode device and the depletion mode device are configured to be complementary conduction, that is, when one device is turned on, the other device is turned off, and vice versa. In actual application, in order to avoid short circuit caused by the simultaneous conduction of the two devices, a certain dead time can be set for the switching action of the upper tube and the lower tube driven by the upper tube driving signal and the lower tube driving signal, and in the dead time, both devices are kept in the off state.

[0045] Since the upper tube is an enhancement mode (E-Mode) device, the circuit is in a safe state without conduction at the moment of high voltage pressurization. Moreover, since the lower tube adopts a depletion mode (D-Mode) device, optimal device performance can be obtained, and the loss is reduced, and the efficiency of the entire half-bridge module is improved. Hereinafter, the upper tube refers to the enhancement mode device; the lower tube refers to the depletion mode device.

[0046] When the half-bridge module is used in a step-down circuit, the duty ratio of the lower tube is usually high, and part of the loss of the step-down circuit mainly comes from the conduction loss and switching loss of the device. Therefore, when the half-bridge module provided in the embodiment is used in a step-down circuit, the lower tube can provide lower conduction loss, and in this case, the performance improvement of the half-bridge module will be more obvious.

[0047] Therefore, the embodiment provides a half-bridge module, which does not have the problem of performance limitation caused by the need for sufficient voltage to maintain the conduction of the depletion mode device in low-voltage applications in the related art. The enhancement mode device is naturally turned off without a control signal, which provides a built-in safety feature. The depletion mode device can quickly respond to the control signal due to its small parasitic capacitance, which reduces the switching loss, and the small resistance can reduce the conduction loss and improve the overall efficiency.

[0048] In one of the embodiments, the enhancement mode device includes any one of a silicon MOSFET, a SiC MOSFET, a pGaN Gate HEMT, and a GaN Trench Gate MIS-HEMT as a normally-off device.

[0049] The depletion mode device includes any one of a SiC JFET, a GaN JFET, a GaN MIS-HEMT, and a Ga2O3 MOSFET as a normally-on device.

[0050] In one of the embodiments, the enhancement mode device and the depletion mode device are packaged together or integrated on the same substrate.

[0051] In one of the embodiments, the half-bridge module further comprises a functional device, the functional device comprising a driver device and / or a logic device;

[0052] The output terminals of the functional device are electrically connected to the gate of the enhancement mode device and the gate of the depletion mode device respectively, so that the gate of the enhancement mode device is connected to the upper gate drive signal through the functional device, and the gate of the depletion mode device is connected to the lower gate drive signal through the functional device.

[0053] Referring to FIG. 5, a half-bridge module is shown, in which a driver device D is used as a functional device. The input terminals of the driver device are connected to a positive power supply voltage VCC, a high-side input signal HIN, a low-side input signal LIN and a negative power supply voltage VSS.

[0054] The function of the driver device (Driver) D is to provide appropriate voltage and current for the gate of the switching device (enhancement mode device and depletion mode device) to ensure that the switching device can be switched quickly and accurately. The driver device D can be a gate driver, a microcontroller (MCU) or a driving IC.

[0055] Referring to FIG. 6, a half-bridge module is shown, in which a driver device D and a logic device L are used as functional devices, and the driver device D is arranged between the logic device L and the gate of the switching device. The input terminals of the logic device L are connected to logic pins (p1, p2, p2…pn) for receiving logic signals.

[0056] The logic device L refers to a logic circuit for controlling the gate signal of the switching device. When the logic device L is arranged between the driver device D and the gate of the switching device, it is used to process the signal from the control terminal of the driver device and generate appropriate gate drive signals to send to the gate of the switching device. For example, a voltage converter or the like.

[0057] In specific applications, the functional device can also include other devices or chips, and the selection thereof is not limited in the present application.

[0058] In a specific application, referring to FIG. 7, the enhancement mode device is a pGaN Gate HEMT, and the depletion mode device is a MIS-HEMT, and the half-bridge module is formed by combining and sealing the pGaN Gate HEMT and the MIS-HEMT. Since the depletion mode device does not have a pGaN island, it is easy to realize a smaller gate length, and the resistance per unit area can be made smaller.

[0059] The half-bridge module disclosed in FIG. 7, the left lower tube is a D-Mode HEMT, and the right upper tube is an E-Mode HEMT. The above-mentioned half-bridge module can realize the positive threshold of the E-Mode HEMT by depleting the 2DEG (two-dimensional electron gas) below the pGaN. The upper tube and the lower tube can be combined and sealed by packaging to realize the integration of the half-bridge module.

[0060] The lower tube includes dielectrics, an aluminum gallium nitride layer (AlGaN), a gallium nitride channel layer (GaN channel), a gallium nitride buffer layer (GaN buffer), and a substrate, which are stacked from top to bottom. The dielectrics serve as a gate insulating layer. The AlGaN layer is a semiconductor material, which is an alloy of aluminum and gallium nitride. In the HEMT structure, the AlGaN layer can act as a barrier layer, which helps to form a two-dimensional electron gas (2DEG). The above-mentioned structure layers are stacked in a certain order to achieve specific electronic properties and performance.

[0061] The source SL of the lower tube is connected to the ground end GND, the gate GL is derived from the structure of the package, and the drain DL is connected to the source SH of the upper tube. The gate GH of the upper tube is derived from the structure of the package, and the drain DH is connected to the high-voltage side power supply VDC.

[0062] Therefore, in the design of the upper and lower tubes of the half-bridge module, the upper tube adopts a pGaN Gate HEMT, which can realize a positive threshold through the above-mentioned mechanism, and the lower tube adopts a MIS-HEMT, which is naturally turned on without a gate voltage. This design combines the advantages of the two devices, improving the performance and safety of the entire module.

[0063] In one embodiment, the enhancement device is an enhancement-mode high electron mobility transistor of a slot gate structure, and the depletion device is a depletion-mode high electron mobility transistor of a metal-insulator-semiconductor structure.

[0064] In another specific application, referring to FIG. 8, the depletion device (lower tube) is a D-Mode MIS-HEMT. By thinning the AlGaN layer, the 2DEG below the gate G can be reduced to realize a positive threshold.

[0065] Referring to FIG. 9, the enhancement device (upper tube) is an E-Mode HEMT of a slot gate structure. Referring to FIG. 10, the upper tube and the lower tube are arranged on the same substrate, which can integrate the above-mentioned half-bridge module on a single chip.

[0066] Switching power supply circuit embodiment.

[0067] The embodiment provides a switching power supply circuit, the switching power supply circuit comprising the half-bridge module in any one of the above embodiments, and specific embodiments can refer to the half-bridge module embodiments, and the embodiment will not be described herein again.

[0068] Referring to FIG. 11, in one embodiment, the switching power supply circuit is a step-down circuit, the step-down circuit comprising a half-bridge module, a low-voltage side load R1 and a driving module, the driving module being configured to generate an upper tube driving signal and a lower tube driving signal and to make the upper tube and the lower tube of the half-bridge module complementary to be turned on, respectively.

[0069] One end of the low-voltage side load R1 is connected to the node of the half-bridge module, and the other end of the low-voltage side load R1 is connected to the source of the depletion type device of the half-bridge module.

[0070] Before the driving circuit is powered on, if a voltage is added to the high-voltage end, the safety of the circuit can be ensured because the upper tube is in a closed state. The driving signal is shown in FIG. 11, the narrow platform corresponds to the upper tube being turned on, and the lower tube being turned off; wherein the upper tube driving pulse PWMH is similar to that in a common half-bridge, and the lower tube driving pulse PWML is inverted and is scaled in the negative voltage direction, and the lowest voltage should be lower than the threshold value of the lower tube to ensure that the lower tube is effectively turned off. Because the upper tube is a normally-off device, at the moment of voltage addition of the high-voltage side VDC, the low-voltage side is in a safe state.

[0071] In one embodiment, the lower tube adopts a GaN D-Mode MIS-HEMT device. In one switching cycle, the lower tube is turned on for a long time, and if the lower tube adopts a GaN D-Mode MIS-HEMT device, compared with an E-Mode pGaN Gate HEMT, the conduction and switching losses can be reduced, and the energy conversion efficiency can be improved.

[0072] In one embodiment, the step-down circuit further comprises a first capacitor C1 and a first inductor L1, one end of the low-voltage side load R1 is connected to the node of the half-bridge module through the first inductor L1, and the first capacitor C1 and the load resistor R1 are connected in parallel.

[0073] The first inductor L1 plays a role of energy storage and smooth current in the switching power supply circuit. Meanwhile, the first capacitor C1 and the load resistor R1 are connected in parallel, when the first inductor L1 releases energy, the first capacitor C1 absorbs part of the energy and stabilizes the output voltage.

[0074] It is to be noted that, as used in this specification and the appended claims, the singular forms "a," "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component" can include a combination of two or more components, and the term "an element" can include comparable reference to a plurality of elements. Also, as used in this specification and the appended claims, the term "or" as used in the context of "A / B" or "A / B / C" means any of the possibilities; for example, the term "or" means "any of A, B, or C; or any of A, B, or C." Further, the term "comprising" as used in this specification and the appended claims, is inclusive or open and does not exclude additional, non-recited members, elements or method steps. Further, the term "comprising" also means "including", "containing" or "characterized by", and the singular encompasses the plural or vice versa unless the context clearly indicates otherwise. Still further, the term "comprising" also means "open" unless the context clearly indicates otherwise.

[0075] The foregoing is considered as illustrative only of the principles of the application. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the application to the exact construction and practice described. Accordingly, all such variations are intended to be included within the scope of the present application as defined in the following claims.

Claims

1. A half-bridge module, characterized in that The half-bridge module comprises an enhancement device as an upper tube and a depletion device as a lower tube; a source of the enhancement device and a drain of the depletion device are electrically connected and form a common node for inputting or outputting power; a drain of the enhancement device is a high-voltage end of the half-bridge module, and a source of the depletion device is a low-voltage end of the half-bridge module; a gate of the enhancement device is used to access an upper tube driving signal, a gate of the depletion device is used to access a lower tube driving signal, and the enhancement device and the depletion device are configured to be complementary on according to the upper tube driving signal and the lower tube driving signal.

2. The half-bridge module according to claim 1, characterized in that The half-bridge module further comprises a functional device, which comprises a driving device and / or a logic device; outputs of the functional device are respectively electrically connected to the gates of the enhancement device and the depletion device, so that the gate of the enhancement device accesses the upper tube driving signal through the functional device, and the gate of the depletion device accesses the lower tube driving signal through the functional device.

3. The half-bridge module of claim 1, wherein, The enhancement device comprises any one of a silicon MOSFET, a SiC MOSFET, a pGaN Gate HEMT, and a GaN Trench Gate MIS-HEMT as a normally-off device. The depletion device comprises any one of a SiC JFET, a GaN JFET, a MIS-HEMT, and a Ga2O3 MOSFET as a normally-on device.

4. The half-bridge module according to claim 3, characterized in that The enhancement device is a pGaN Gate HEMT, and the depletion device is a MIS-HEMT; the enhancement device depletes two-dimensional electron gas through a pGaN island to realize a positive threshold.

5. The half-bridge module of claim 1, wherein, The enhancement device is an enhancement-mode high electron mobility transistor of a trench gate structure, and the depletion device is a depletion-mode high electron mobility transistor of a metal-insulator-semiconductor structure.

6. The half-bridge module of claim 1, wherein, The enhancement device and the depletion device are sealed together or integrated on the same substrate.

7. A switching power supply circuit, characterized by comprising: The switching power supply circuit comprises the half-bridge module of any one of claims 1-6.

8. The switching power supply circuit according to claim 7, characterized in that, The switching power supply circuit is a step-down circuit, and the step-down circuit further comprises a low-voltage side load and a driving module; The driving module is used to generate upper tube driving signals and lower tube driving signals and to complementally turn on upper tubes and lower tubes of the half-bridge module, respectively; one end of the low-voltage side load is connected to the node of the half-bridge module, and the other end of the low-voltage side load is connected to the source of the depletion device of the half-bridge module.

9. The switching power supply circuit according to claim 8, characterized in that, The depletion device of the half-bridge module comprises a GaN D-Mode MIS-HEMT device.

10. The switching power supply circuit according to claim 8, characterized in that, The switching power supply circuit further comprises a first capacitor and a first inductor, one end of the low-voltage side load is connected to the node of the half-bridge module through the first inductor, and the first capacitor and the load resistor are connected in parallel.

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