Control device based on GaN power tube and switching power supply

Abstract

The invention provides a controller based on a GaN power tube and a switching power supply. The GaN-based controller comprises a logic control module, a driving module, a metal oxide semiconductor field effect transistor (MOSFET), a GaN power tube and a driving adjustment module, wherein the logic control module generates a logic control signal based on a feedback signal received by a feedback terminal of a control device and a sampling signal received by a sampling terminal of the control device; the driving module generates a driving signal based on the logic control signal; the MOSFET is turned on or turned off in response to a driving signal; and the GaN power tube responds to the turn-on or turn-off of the MOSFET and is turned on or turned off under the control of the driving adjustment module.

Description

Technical Field

[0001] The present application relates to the technical field of switching power supplies, and more specifically, to a control device and a switching power supply based on a GaN power tube. Background Art

[0002] GaN is suitable for higher switching frequencies, can reduce switching losses compared to traditional metal-oxide semiconductor field effect transistors (Mosfet), and has low drain-source on-resistance (Rdson). Its application in switching power supplies can significantly improve system efficiency, so the application of GaN has increased rapidly in recent years. Enhanced GaN (E-mode GaN) drive is relatively simple and more suitable for medium and small power applications. Depletion mode GaN (D-mode GaN) drive requires Mosfet, but has higher reliability and is more suitable for medium and large power applications. Summary of the invention

[0003] In one aspect, according to an embodiment of the present application, a control device based on a GaN power tube is provided, comprising: a logic control module, a driving module, a metal oxide semiconductor field effect transistor MOSFET, a GaN power tube and a driving regulation module, wherein the logic control module generates a logic control signal based on a feedback signal received by a feedback terminal of the control device and a sampling signal received by a sampling terminal of the control device; the driving module generates a driving signal based on the logic control signal; the MOSFET is turned on or off in response to the driving signal; and the GaN power tube is turned on or off in response to the turning on or off of the MOSFET and under the control of the driving regulation module.

[0004] In one aspect, a switching power supply is provided according to an embodiment of the present application, including a control device provided according to an embodiment of the present application.

[0005] According to the GaN-based control device and switching power supply provided by the embodiments of the present application, by adding a driving adjustment module to the gate end of the GaN power tube, the switching speed of the GaN power tube can be adjusted, thereby optimizing the system electromagnetic interference (EMI). BRIEF DESCRIPTION OF THE DRAWINGS

[0006] In order to make the purpose, scheme and advantages of the present application clearer, the present application is further described in detail below in conjunction with the drawings and embodiments. When reading the following specific description in conjunction with the drawings, the various aspects of the present application can be best understood through the following specific description. It should be understood that the specific embodiments described herein are only used to explain the present application and are not intended to limit the present application. Note that various features are not necessarily drawn to scale according to standard industry practices. In the various figures, similar numerical labels describe similar components. In the drawings:

[0007] Figure 1 The I / V characteristic curve of D-mode GaN is shown;

[0008] Figure 2 A circuit diagram of a conventional GaN power tube-based control device is shown;

[0009] Figure 3 A waveform diagram of a conventional GaN power tube-based control device is shown;

[0010] Figure 4 A circuit diagram of a control device based on a GaN power tube according to an embodiment of the present application is shown;

[0011] Figure 5 A circuit diagram of a control device based on a GaN power tube according to an embodiment of the present application is shown;

[0012] Figure 6 A circuit diagram of a control device based on a GaN power tube according to an embodiment of the present application is shown;

[0013] Figure 7 A circuit diagram of a control device based on a GaN power tube according to an embodiment of the present application is shown;

[0014] Figure 8 A circuit diagram of a resistance-adjustable branch according to an embodiment of the present application is shown.

[0015] Fig. 9 A circuit diagram of a control device based on a GaN power tube according to an embodiment of the present application is shown;

[0016] Fig.10 A circuit diagram of a control device based on a GaN power tube according to an embodiment of the present application is shown; and

[0017] Fig.11 A system schematic diagram of a switching power supply including a control device based on a GaN power tube according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0018] The features and exemplary embodiments of various aspects of the application will be described in detail below. In the detailed description below, many specific details are proposed to provide a comprehensive understanding of the application. However, it is obvious to those skilled in the art that the application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the application by illustrating the example of the application. The application is by no means limited to any specific configuration and algorithm proposed below, but covers any modification, replacement and improvement of elements, parts and algorithms without departing from the spirit of the application. In the accompanying drawings and the following description, known structures and technologies are not shown to avoid causing unnecessary ambiguity to the application.

[0019] Figure 1 The I / V characteristic curve of D-mode GaN is shown. The I / V characteristic of D-mode GaN is similar to that of junction field effect transistor (JFET) and depletion mode MOSFET. When D-mode GaN is used in switching power supply, a low voltage MOSFET needs to be connected in series at its lower end for switch control. The Rdson of low voltage MOSFET is usually about 1 / 10 of that of D-mode GaN.

[0020] Figure 2 FIG. 1 shows a circuit diagram of a conventional GaN power tube-based control device. Figure 2 As shown, a conventional GaN power tube-based control device 200 includes: a logic control module 201, a driving module 202, a metal oxide semiconductor field effect transistor MOSFET M2 and a GaN power tube M1, wherein the logic control module 201 generates a logic control signal based on a feedback signal received by a feedback terminal FB of the control device 200 and a sampling signal received by a sampling terminal CS of the control device 200; the driving module 202 generates a driving signal based on the logic control signal; the MOSFET M2 is turned on or off in response to the driving signal; and the GaN power tube M1 is turned on or off in response to the turning on or off of the MOSFET M2.

[0021] In addition, if Figure 2 As shown, the conventional GaN power tube-based control device 200 further includes a power module 203. The power module 203 provides supply voltage, voltage and current bias, etc. for other modules (eg, logic control module 201, driving module 202). Figure 2 The control device 200 shown can be applied to a switching power supply. Figure 2As shown, when applied to a switching power supply, the power terminal (pin) Vcc of the control device 200 will be connected to the input module of the switching power supply and grounded via the first capacitor C1, the feedback terminal FB of the control device 200 will be connected to the output feedback of the switching power supply, the sampling terminal CS of the control device 200 will be grounded via the sampling resistor Rsense, and the drain terminal of the GaN power tube M1 of the control device 200 will serve as the output terminal Drain of the control device and be connected to the output module of the switching power supply (such as the primary winding Lp of the transformer in the output module).

[0022] like Figure 2 The main working principle of the conventional GaN power tube-based control device 200 shown is as follows: directly controlling the gate voltage Gate2 of MOSFET M2 through a driving signal to indirectly control the on and off of GaN power tube M1, that is, when the gate voltage Gate2 of MOSFET M2 is at a high level, MOSFET M2 is turned on, the source voltage Vds2 of GaN power tube M1 is reduced, and GaN power tube M1 is turned on. When the gate voltage Gate2 of MOSFET M2 is at a low level, MOSFET M2 is turned off, and the source voltage Vds2 of GaN power tube M1 increases, causing GaN power tube M1 to pinch off.

[0023] Since the gate terminal of the GaN power tube M1 is directly connected to the source terminal of the MOSFET M2 at its lower end, that is, the sampling terminal CS, and the source terminal of the GaN power tube M1 is cascaded to the drain terminal of the MOSFET M2, the gate-source voltage of the GaN power tube M1 is only controlled by the switch of the MOSFET M2, that is, the switching speed of the GaN power tube M1 is only controlled by the switching speed of the MOSFET M2. Therefore, it is difficult to adjust the electromagnetic interference EMI of the system, and at the moment when the MOSFET M2 is turned off, the source voltage Vds2 of the GaN power tube M1 increases instantly, which may exceed the withstand voltage of the gate-source voltage of the GaN power tube M1, thereby reducing the reliability.

[0024] Figure 3 Shows Figure 2 The waveform diagram of the conventional GaN power tube based control device. Figure 3 In the figure, Vds represents the drain-source voltage of MOSFET M2, which is also the source voltage of GaN power tube M1, Gate2 represents the gate voltage of MOSFET M2, and Ip represents the current flowing through GaN power tube M1. Figure 3As shown, when the gate voltage Gate2 of MOSFET M2 is high, MOSFET M2 is turned on, the source voltage Vds2 of GaN power tube M1 is reduced, GaN power tube M1 is turned on, and the current Ip flowing through GaN power tube M1 gradually increases. When the gate voltage Gate2 of MOSFET M2 is low, MOSFET M2 is turned off, the source voltage Vds2 of GaN power tube M1 increases, causing GaN power tube M1 to be pinched off, and the current Ip flowing through GaN power tube M1 is zero. It can be seen that the switching speed of GaN power tube M1 is only controlled by the switching speed of MOSFET M2 at its lower end. As mentioned above, this makes it difficult to adjust the electromagnetic interference EMI of the system and reduces reliability.

[0025] In view of the above, the embodiments of the present application propose a control device and a switching power supply based on a GaN power tube, so that the switching speed of the GaN power tube is no longer only controlled by the switching speed of the MOSFET M2 at its lower end, but is adjustable.

[0026] Figure 4 A circuit diagram of a control device based on a GaN power tube according to an embodiment of the present application is shown.

[0027] like Figure 4 As shown, the control device 400 based on the GaN power tube according to the embodiment of the present application includes: a logic control module 401, a driving module 402, a metal oxide semiconductor field effect transistor MOSFET M1, a GaN power tube M1 and a driving adjustment module 403, wherein the logic control module 401 generates a logic control signal based on a feedback signal received by a feedback terminal FB of the control device 400 and a sampling signal received by a sampling terminal CS of the control device 400; the driving module 402 generates a driving signal based on the logic control signal; the MOSFET M2 is turned on or off in response to the driving signal; and the GaN power tube M1 is turned on or off in response to the turning on or off of the MOSFET M2 and under the control of the driving adjustment module 403.

[0028] In addition, if Figure 4 As shown, the control device 400 based on the GaN power tube according to the embodiment of the present application further includes a power supply module 404 and a high-voltage startup module 405 .

[0029] The power module 404 provides supply voltage, voltage and current bias, etc. for other modules (such as the logic control module 401 and the high voltage startup module 405). In some implementations, the power module 404 may include a power terminal Vcc startup control circuit, an LDO circuit, a basic reference voltage source, and a current source.

[0030] The high-voltage startup module 405 controls the startup of the control device 400. Specifically, in the initial state of the control device 400, the power supply terminal Vcc of the control device 400 is at a low voltage, and the GaN switch tube M1 is in a conducting state. During the startup process of the control device 400, the input voltage received by the drain terminal Drain of the GaN switch tube M1 is charged to the power supply capacitor C1 of the control device 400 via the high-voltage startup module 405, the power module 404, and then via the power supply terminal Vcc. When the voltage on the power supply terminal Vcc (i.e., the voltage on the power supply capacitor C1) reaches the startup voltage of the control device 400, the control device 400 is started.

[0031] In some implementations, such as Figure 4 As shown, the first input end of the logic control module 401 is connected to the feedback terminal FB, and the second input end of the logic control module 401 is connected to the sampling terminal CS; the input end of the driving module 402 is connected to the output end of the logic control module 401; the gate end of the MOSFET M2 is connected to the output end of the driving module 402, and the source end of the MOSFET M2 is connected to the sampling terminal CS; the source end of the GaN power tube M1 is connected to the drain end of the MOSFET M2, and the drain end Drain of the GaN power tube M1 serves as the output end of the control device 400; and the first end of the driving adjustment module 403 is connected to the gate end of the GaN power tube M1, and the second end of the driving adjustment module 403 is connected to the source end of the MOSFET M2.

[0032] In addition, if Figure 4 As shown, a first end of the power module 404 is connected to the power terminal Vcc, a second end of the power module 404 is connected to the logic control module 401, and a third end of the power module 404 is connected to a first end of the high-voltage startup module 405, and a second end of the high-voltage startup module 405 is connected to the source of the GaN power tube M1. Figure 4 The control device 400 shown can be applied to a switching power supply. Figure 4 As shown, when applied to a switching power supply, the power terminal Vcc of the control device 400 will be connected to the input module of the switching power supply and grounded via the power supply capacitor (first capacitor) C1, the feedback terminal FB of the control device 400 will be connected to the output feedback of the switching power supply, the sampling terminal CS of the control device 400 will be grounded via the sampling resistor Rsense, and the drain terminal Drain of the GaN power tube M1 of the control device 400 will be connected to the output module of the switching power supply (such as the primary winding Lp of the transformer in the output module) as the output end of the control device.

[0033] Compared to Figure 2The conventional control device based on GaN power tube shown in the figure has a driving adjustment module added to the control device according to the embodiment of the present application. By adding the driving adjustment module to the gate end of the GaN power tube, the switching speed of the GaN power tube can be adjusted, thereby optimizing the system electromagnetic interference (EMI).

[0034] Figure 5 A circuit diagram of a control device based on a GaN power tube according to an embodiment of the present application is shown. Figure 5 Configuration and Figure 4 The configuration is the same as in, and the specific structure of the high-voltage starting module 405 is particularly shown.

[0035] like Figure 5 As shown, the high-voltage startup module 405 includes a first diode D1, a first resistor R1 and a first switch S1 connected in series, wherein the first diode D and the first switch S1 are connected to the power module 404 and the GaN power tube M1 respectively. In addition, the first switch S1 is turned on or off according to the signal from the power module 404. Specifically, in the initial state of the control device 400, the power terminal Vcc of the control device 400 is a low voltage, and the first switch S1 is turned on according to the signal from the power module 404, so that the input voltage received by the drain terminal Drain of the GaN switch tube M1 during the startup process of the control device 400 can be charged to the power supply capacitor C1 of the control device 400 via the high-voltage startup module 405, the power module 404 and then via the power terminal Vcc. When the voltage on the power terminal Vcc (that is, the voltage on the power supply capacitor C1) reaches the startup voltage of the control device 400, the control device 400 is started, and at this time, the first switch S1 is disconnected according to the signal from the power module 404.

[0036] Figure 6 A circuit diagram of a control device based on a GaN power tube according to an embodiment of the present application is shown.

[0037] like Figure 6 As shown, the control device 600 based on the GaN power tube according to the embodiment of the present application includes: a logic control module 601, a driving module 602, a metal oxide semiconductor field effect transistor MOSFET M1, a GaN power tube M1 and a driving adjustment module 603, wherein the logic control module 601 generates a logic control signal based on a feedback signal received by a feedback terminal FB of the control device 600 and a sampling signal received by a sampling terminal CS of the control device 600; the driving module 602 generates a driving signal based on the logic control signal; the MOSFET M2 is turned on or off in response to the driving signal; and the GaN power tube M1 is turned on or off in response to the turning on or off of the MOSFET M2 and under the control of the driving adjustment module 603.

[0038] In addition, if Figure 6 As shown, the GaN power tube-based control device 600 according to the embodiment of the present application further includes a power module 604 and a high-voltage startup module 605. The power module 604 provides supply voltage, voltage and current bias, etc. for other modules (such as the logic control module 601 and the high-voltage startup module 605). The high-voltage startup module 606 implements the control of the startup of the control device 600.

[0039] Figure 6 The logic control module 601, the driving module 602, the metal oxide semiconductor field effect transistor MOSFETM1, the GaN power tube M1, the driving adjustment module 603, the power module 604 and the high voltage starting module 605 are connected to the Figure 4 The connections of the logic control module 401, the driving module 402, the metal oxide semiconductor field effect transistor MOSFET M1, the GaN power tube M1, the driving adjustment module 403, the power module 404 and the high voltage startup module 405 are the same and will not be repeated here. Figure 6 The control device 600 shown in FIG. 1 can be applied to a switching power supply. Figure 4 The connections of the terminals of the control device 400 shown in FIG. 4 are the same and will not be repeated here.

[0040] In addition, if Figure 6 As shown, the driving adjustment module 603 includes: a second resistor R2, a second diode D21 and a third resistor R3, wherein a first end of the second resistor R2 is connected to the gate end of the GaN power tube M1, a second end of the second resistor R2 is connected to the source end of the MOSFET M2, a first end of the second diode D2 is connected to the gate end of the GaN power tube M1, a second end of the second diode D2 is connected to the first end of the third resistor R3, and a second end of the third resistor R3 is connected to the source end of the MOSFET M2, wherein the second resistor R2 and the third resistor R3 each have a fixed resistance.

[0041] The second resistor R2 (rising edge resistor), the second diode D2, and the third resistor R3 (falling edge resistor) included in the driving adjustment circuit 603 can realize the switching speed adjustment of the turning-on rising edge and pinching-off falling edge of the GaN power tube M1. Generally, the resistance value of the second resistor R2 is greater than the resistance value of the third resistor R3. The larger the resistance value of the second resistor R2, the slower the turning-on speed of the GaN power tube M1. Conversely, the smaller the resistance value of the second resistor R2, the faster the turning-on speed of the GaN power tube M1. Similarly, the larger the resistance value of the third resistor R3, the slower the turning-off speed of the GaN power tube M1. Conversely, the smaller the resistance value of the third resistor R3, the faster the turning-off speed of the GaN power tube M1. By adjusting the resistance values ​​of the rising edge and falling edge resistors, the purpose of optimizing electromagnetic interference EMI can be achieved.

[0042] Figure 7 A circuit diagram of a control device based on a GaN power tube according to an embodiment of the present application is shown.

[0043] like Figure 7 As shown, the control device 700 based on the GaN power tube according to the embodiment of the present application includes: a logic control module 701, a driving module 702, a metal oxide semiconductor field effect transistor MOSFET M1, a GaN power tube M1 and a driving adjustment module 703, wherein the logic control module 701 generates a logic control signal based on a feedback signal received by a feedback terminal FB of the control device 700 and a sampling signal received by a sampling terminal CS of the control device 700; the driving module 702 generates a driving signal based on the logic control signal; the MOSFET M2 is turned on or off in response to the driving signal; and the GaN power tube M1 is turned on or off in response to the turning on or off of the MOSFET M2 and under the control of the driving adjustment module 703.

[0044] In addition, if Figure 7 As shown, the GaN power tube-based control device 700 according to the embodiment of the present application further includes a power supply module 704 and a high-voltage startup module 705. The power supply module 704 provides supply voltage, voltage and current bias, etc. for other modules (such as the logic control module 701 and the high-voltage startup module 705). The high-voltage startup module 705 implements the control of the startup of the control device 700.

[0045] Figure 7 The logic control module 701, the driving module 702, the metal oxide semiconductor field effect transistor MOSFETM1, the GaN power tube M1, the driving adjustment module 703, the power module 704 and the high voltage starting module 705 are connected to the Figure 4 The connections of the logic control module 401, the driving module 402, the metal oxide semiconductor field effect transistor MOSFET M1, the GaN power tube M1, the driving adjustment module 403, the power module 404 and the high voltage startup module 405 are the same and will not be repeated here. Figure 7 The control device 700 shown in FIG. 1 can be applied to a switching power supply. Figure 4 The connections of the terminals of the control device 400 shown in FIG. 4 are the same and will not be repeated here.

[0046] In addition, if Figure 7As shown, the driving adjustment module 703 includes: a first adjustable resistance branch 703-1, a second diode D2 and a second adjustable resistance branch 703-2, wherein the first end of the first adjustable resistance branch 703-1 is connected to the gate end of the GaN power tube M1, the second end of the first adjustable resistance branch 703-1 is connected to the source end of the MOSFET M2, the first end of the second diode D2 is connected to the gate end of the GaN power tube M1, the second end of the second diode D1 is connected to the first end of the second adjustable resistance branch 703-2, and the second end of the second adjustable resistance branch 703-2 is connected to the source end of the MOSFET M2, and wherein the first adjustable resistance branch 703-1 adjusts the first adjustable resistance of the first adjustable resistance branch 703-1 in response to the first switch control signal Sr[1:n] from the logic control module 701, and the second adjustable resistance branch 703-2 adjusts the second adjustable resistance of the second adjustable resistance branch 703-2 in response to the second switch control signal Sf[1:n] from the logic control module 701. Figure 8 FIG. 1 shows a circuit diagram of a resistance adjustable branch according to an embodiment of the present application. Figure 8 As shown, the first adjustable resistance branch 703-1 includes: at least two fourth resistors Rr[1:n] connected in series and switches S[1:n] respectively connected in parallel with each of the at least two fourth resistors Rr[1:n], wherein the switches S[1:n] respectively connected in parallel with each of the at least two fourth resistors Rr[1:n] are independently controlled to be turned on or off in response to the first switch control signal Sr[1:n] from the logic control module 701; and the fifth adjustable resistance branch 703-2 includes: at least two fifth resistors Rf[1:n] connected in series and switches W[1:n] respectively connected in parallel with each of the at least two fifth resistors Rf[1:n], wherein the switches W[1:n] respectively connected in parallel with each of the at least two fifth resistors Rf[1:n] are independently controlled to be turned on or off in response to the second switch control signal Sf[1:n] from the logic control module 701. It should be understood that at least two fourth resistors Rr[1:n] may be the same or different; at least two fifth resistors Rf[1:n] may be the same or different. The resistance of the fourth resistor Rr[1:n] may be the same or different from the resistance of the fifth resistor Rf[1:n].

[0047] More specifically, if Figure 8 As shown, the switch S[1:n] of the first adjustable resistance branch 703-1 is controlled by the first switch control signal Sr[1:n], so that the resistance of the first adjustable resistance branch 703-1 can be adjusted from 0 to Rr1+Rr2+…Rrn, thereby achieving precise adjustment of the rising edge conduction speed. Figure 8As shown, the switch W[1:n] of the second adjustable resistance branch 703-2 is controlled by the second switch control signal Sf[1:n], so that the resistance of the second adjustable resistance branch 703-2 can be adjusted from 0 to Rf1+Rf2+…Rfn, thereby achieving precise adjustment of the falling edge turn-off speed. In this way, the purpose of optimizing EMI for the control device and the switching power supply based on GaN power tubes with different Rdson can be achieved.

[0048] Each of the switch S[1:n] of the first adjustable resistance branch 703-1 and the switch W[1:n] of the second adjustable resistance branch 703-2 may be any circuit switch, including but not limited to a semiconductor control switch such as a MOS tube and a triode.

[0049] According to the above embodiment, by adding the first adjustable resistance branch 703-1 and the second adjustable resistance branch 703-2 to receive the first switch control signal Sr[1:n] and the second switch control signal Sf[1:n] provided by the logic control module 701, the resistance of the first adjustable resistance branch 703-1 and the second adjustable resistance branch 703-2 can be adjusted respectively. In this way, when using a GaN power tube M1 with different Rdson, the switching speed of the turn-on rising edge and the pinch-off falling edge of the GaN power tube M1 can be adjusted by adjusting the resistance of the first adjustable resistance branch 703-1 and the second adjustable resistance branch 703-2, so as to achieve the purpose of optimizing EMI, and the design is more flexible.

[0050] Fig. 9 A circuit diagram of a control device based on a GaN power tube according to an embodiment of the present application is shown.

[0051] like Fig. 9 As shown, the control device 900 based on the GaN power tube according to the embodiment of the present application includes: a logic control module 901, a driving module 902, a metal oxide semiconductor field effect transistor MOSFET M1, a GaN power tube M1 and a driving adjustment module 903, wherein the logic control module 901 generates a logic control signal based on a feedback signal received by a feedback terminal FB of the control device 900 and a sampling signal received by a sampling terminal CS of the control device 900; the driving module 902 generates a driving signal based on the logic control signal; the MOSFET M2 is turned on or off in response to the driving signal; and the GaN power tube M1 is turned on or off in response to the turning on or off of the MOSFET M2 and is turned on or off under the control of the driving adjustment module 903.

[0052] In addition, if Fig. 9As shown, the GaN power tube-based control device 900 according to the embodiment of the present application further includes a power module 904 and a high-voltage startup module 905. The power module 904 provides supply voltage, voltage and current bias, etc. for other modules (such as the logic control module 901 and the high-voltage startup module 905). The high-voltage startup module 905 implements the control of the startup of the control device 900.

[0053] Fig. 9 The logic control module 901, the driving module 902, the metal oxide semiconductor field effect transistor MOSFETM1, the GaN power tube M1, the driving adjustment module 903, the power module 904 and the high voltage starting module 905 are connected to the Figure 4 The connections of the logic control module 401, the driving module 402, the metal oxide semiconductor field effect transistor MOSFET M1, the GaN power tube M1 and the driving adjustment module 403, the power module 404 and the high voltage startup module 405 are the same and will not be repeated here. Fig. 9 The control device 900 shown in FIG. 1 can be applied to a switching power supply. Figure 4 The connections of the terminals of the control device 400 shown in FIG. 4 are the same and will not be repeated here.

[0054] In addition, if Fig. 9 As shown, the control device 900 according to the embodiment of the present application further includes a voltage clamping circuit 906, which is configured to clamp the voltage at the source end of the GaN power tube M1 to a clamping voltage at the moment when the GaN power tube M1 is turned off. Fig. 9 As shown, the voltage clamp circuit 906 is connected to the source terminal of the GaN power transistor M1.

[0055] Fig.10 A circuit diagram of a control device based on a GaN power tube according to an embodiment of the present application is shown.

[0056] like Fig.10 As shown, the control device 1000 based on the GaN power tube according to the embodiment of the present application includes: a logic control module 1001, a driving module 1002, a metal oxide semiconductor field effect transistor MOSFET M1, a GaN power tube M1 and a driving adjustment module 1003, wherein the logic control module 1001 generates a logic control signal based on a feedback signal received by a feedback terminal FB of the control device 1000 and a sampling signal received by a sampling terminal CS of the control device 1000; the driving module 1002 generates a driving signal based on the logic control signal; the MOSFET M2 is turned on or off in response to the driving signal; and the GaN power tube M1 is turned on or off in response to the turning on or off of the MOSFET M2 and under the control of the driving adjustment module 1003.

[0057] In addition, if Fig.10 As shown, the control device 1000 based on the GaN power tube according to the embodiment of the present application further includes a power module 1004 and a high-voltage startup module 1005. The power module 1004 provides a supply voltage, a voltage and a current bias, etc. for other modules (such as the logic control module 1001 and the high-voltage startup module 1005). The high-voltage startup module 1005 implements the control of the startup of the control device 1000.

[0058] Fig.10 The logic control module 1001, the driving module 1002, the metal oxide semiconductor field effect transistor MOSFET M1, the GaN power tube M1, the driving adjustment module 1003, the power module 1004 and the high voltage starting module 1005 are connected to the Fig. 9 The connections of the logic control module 901, the driving module 902, the metal oxide semiconductor field effect transistor MOSFET M1, the GaN power tube M1, the driving adjustment module 903, the power module 904 and the high voltage startup module 905 are the same and will not be repeated here. Fig.10 The control device 1000 shown in FIG. 1 can be applied to a switching power supply. Fig. 9 The connections of the terminals of the control device 900 shown in FIG. 1 are the same and will not be repeated here.

[0059] In addition, if Fig.10 As shown, the control device 1000 according to the embodiment of the present application further includes a voltage clamping circuit 1006, which is configured to clamp the voltage at the source end of the GaN power tube M1 to a clamping voltage at the moment when the GaN power tube M1 is turned off. Fig.10 As shown, the voltage clamp circuit 1006 is connected to the source terminal of the GaN power transistor M1.

[0060] like Fig.10 As shown, the voltage clamp circuit 1006 includes: a Zener diode D3, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and a third power tube M3, wherein a first end of the Zener diode D3 is connected to a source terminal of the GaN power tube M1, a second end of the Zener diode D3 is connected to a first end of the fifth resistor R5, a second end of the fifth resistor R5 is connected to a first end of the sixth resistor R6, and a second end of the sixth resistor R6 is grounded; and wherein a first end of the seventh resistor R7 is connected to a source terminal of the GaN power tube M1, a second end of the seventh resistor R7 is connected to a drain terminal of the third power tube M3, a gate terminal of the third power tube M3 is connected to a connection point between a second end of the fifth resistor R5 and a first end of the sixth resistor R6, and a source terminal of the third power tube M3 is grounded.

[0061] like Fig.10 As shown, the clamping voltage Vclamp can be determined as:

[0062]

[0063] Wherein, Vth_M3 is the conduction threshold voltage of the third switch tube M3, and Vzener is the voltage on the Zener diode. When the source voltage Vds2 of the GaN power tube M1 exceeds the clamping voltage Vclamp, the third switch tube M3 is turned on, and the source voltage Vds2 of the GaN power tube M1 is clamped at the clamping voltage Vclamp through the current limiting resistor R7.

[0064] According to reference Fig. 9 and Fig.10 In the above described embodiments, a voltage clamping module 906 / 1006 is added to the source terminal of the GaN power tube M1 to prevent the voltage at the source terminal of the GaN power tube M1 from being too high and exceeding the withstand voltage of the gate-source voltage VGS of the GaN power tube M1 at the moment of shutdown, thereby preventing the device from being damaged. This can enhance the reliability of the device operation.

[0065] Although in the above description, the voltage clamping module 906 / 1006 and the driving regulating module 903 / 1003 exist simultaneously, it should be understood that the voltage clamping module 906 / 1006 may be included while the driving regulating module 903 / 1003 may be omitted to achieve the effect of enhancing the reliability of the device operation.

[0066] Fig.11 A system schematic diagram of a switching power supply including a control device based on a GaN power tube according to an embodiment of the present application is shown.

[0067] like Fig.11 As shown, the switching power supply 1100 according to the embodiment of the present application includes: an input device 1101 , a control device 1102 and an output device 1103 .

[0068] The control device 1102 may be implemented by using any one of the control devices 400 , 500 , 600 , 800 , and 900 in the above-mentioned embodiments.

[0069] In some implementations, such as Fig.11As shown, the control device 1102 according to the embodiment of the present application includes: a logic control module 1102-1, a driving module 1102-2, a metal oxide semiconductor field effect transistor MOSFET M1, a GaN power tube M1 and a driving adjustment module 1102-3, wherein the logic control module 1102-1 generates a logic control signal based on a feedback signal received by a feedback terminal FB of the control device 1100 and a sampling signal received by a sampling terminal CS of the control device 1100; the driving module 1102-2 generates a driving signal based on the logic control signal; the MOSFET M2 is turned on or off in response to the driving signal; and the GaN power tube M1 is turned on or off in response to the turning on or off of the MOSFET M2 and under the control of the driving adjustment module 1102-3.

[0070] In addition, if Fig.11 As shown, the control device 1102 according to the embodiment of the present application further includes a power supply module 1102-4 and a high-voltage startup module 1102-5. The power supply module 1102-4 provides supply voltage, voltage and current bias, etc. for other modules (such as the logic control module 1102-1 and the high-voltage startup module 1102-5). The high-voltage startup module 905 implements the control of the startup of the control device 1102.

[0071] Fig.11 The logic control module 1102-1, the driving module 1102-2, the metal oxide semiconductor field effect transistor MOSFET M1, the GaN power tube M1, the driving regulation module 1102-3, the power module 1102-4 and the high voltage startup module 1102-5 are connected to the Figure 4 The connections among the logic control module 401, the driving module 402, the metal oxide semiconductor field effect transistor MOSFET M1, the GaN power tube M1, the driving regulation module 403, the power module 404 and the high voltage starting module 405 are the same and will not be described again.

[0072] In addition, if Fig.11 As shown, the control device 1102 according to the embodiment of the present application further includes a voltage clamping circuit 1102-6, which is configured to clamp the voltage at the source end of the GaN power tube M1 to a clamping voltage at the moment when the GaN power tube M1 is turned off. Fig.11 As shown, the voltage clamp circuit 1102 - 6 is connected to the source terminal of the GaN power tube M1 .

[0073] In some implementations, the logic control module 1102-1 includes: an eighth resistor R8, a ninth resistor R9, a comparator Comp and an SR trigger, wherein the first end of the eighth resistor R8 is connected to the feedback terminal FB, the second end of the eighth resistor R8 is connected to the first end of the ninth resistor R9, and the second end of the ninth resistor R9 is grounded; the positive input end of the comparator Comp is connected to the connection point between the second end of the eighth resistor R8 and the first end of the ninth resistor R9, the negative input end of the comparator Comp is connected to the sampling terminal FB, and the first input end of the SR trigger receives an oscillation signal generated by the oscillator OSC, the second input end of the SR trigger is connected to the output end of the comparator Comp, and the output end of the SR trigger is connected to the driving module 1102-3.

[0074] In some implementations, the driving module 1102 - 2 includes: a driving circuit based on a MOS transistor, such as a totem pole driving circuit.

[0075] like Fig.11 As shown, the input device 1101 includes: an AC source AC, a rectifier circuit DR, a first capacitor C1, a second capacitor C2, a tenth resistor R10, a transformer T1 and a fourth diode D4, wherein the input end of the rectifier circuit DR is connected to the AC source AC to receive the AC input Vin, the first end of the second capacitor C2 is connected to the output end of the rectifier circuit DR, the second end of the second capacitor C2 is grounded, the first end of the tenth resistor R10 is connected to the output end of the rectifier circuit DR, the second end of the tenth resistor R10 is connected to the first end of the first capacitor C1, the second end of the first capacitor C1 is grounded, the first end of the secondary winding of the transformer T1 is connected to the connection point of the second end of the tenth resistor R10 and the first end of the first capacitor C1 via the fourth diode D4, and the second end of the secondary winding of the transformer T1 is grounded. The connection point of the second end of the tenth resistor R10 and the first end of the first capacitor C1 is connected to the power supply terminal Vcc of the control device 1102 to provide the control device 1102 with a power supply voltage.

[0076] like Fig.11As shown, the output device 1103 includes a second transformer T2, a fifth diode D5, a third capacitor C3, and a feedback and isolation circuit F&I, wherein the first end of the primary side of the second transformer T2 is connected to the output end of the rectifier circuit DR in the input device 1101, the second end of the primary side of the second transformer T2 is connected to the output terminal of the control device 1102, that is, the drain end Drain of the GaN power tube M1, the first end of the secondary side of the second transformer T2 is connected to the first end of the fifth diode D5, the second end of the secondary side of the second transformer T2 is grounded, the second end of the fifth diode D5 is grounded via the third capacitor C3 and connected to the input end of the feedback and isolation circuit F&I, and the output end of the feedback and isolation circuit F&I is connected to the feedback terminal FB of the control device 1102 to provide output feedback therefor. The sampling resistor Rsense is connected between the sampling terminal CS of the control device 1102 and the ground.

[0077] According to the switching power supply of the embodiment of the present application, by adding a driving adjustment module 1102-3 to the gate end of the GaN power tube M1, the switching speed of the GaN power tube can be adjusted, thereby optimizing the system electromagnetic interference (EMI). By adding a voltage clamping module 1102-6 to the source end of the GaN power tube M1, the voltage at the source end of the GaN power tube M1 is prevented from being too high at the moment of shutdown, exceeding the gate-source voltage VGS of the GaN power tube M1, thereby causing damage to the device, and the reliability of the device operation can be enhanced. In addition, by adding a high-voltage startup control module 1102-5, the system standby power consumption can be reduced.

[0078] It should be understood that the GaN power tube according to the embodiment of the present application can be a depletion-type GaN power tube. It should also be understood that the above description is based on the switching power supply of the flyback architecture, but the embodiment of the present application can also be applied to power supply architectures such as Buck architecture, Boost architecture, Buck-boost architecture, LLC architecture and AHB architecture.

[0079] The mechanism of the present application has been described above with reference to the accompanying drawings and various embodiments. It should be understood that the present application is not limited thereto, but can be implemented in other forms without departing from the subject matter and essential features of the present application. The current embodiments are to be considered in all respects as illustrative rather than restrictive, the scope of the present invention is defined by the appended claims rather than the above description, and all changes falling within the meaning and equivalents of the claims are included within the scope of the present application.

Claims

1. A control device based on a GaN power tube, comprising: Logic control module, drive module, metal oxide semiconductor field effect transistor MOSFET, GaN power tube and drive regulation module, The logic control module generates a logic control signal based on a feedback signal received by a feedback terminal of the control device and a sampling signal received by a sampling terminal of the control device; The driving module generates a driving signal based on the logic control signal; The MOSFET is turned on or off in response to the driving signal; and The GaN power tube responds to the turning on or off of the MOSFET and is turned on or off under the control of the driving and regulating module.

2. The control device according to claim 1 further includes a power supply module and a high-voltage startup module, wherein the power supply module provides a power supply voltage for the high-voltage startup module and the logic control module, and the startup control module controls the power-on startup of the control device.

3. The control device according to claim 2, wherein: The first end of the power module is connected to the power supply terminal of the control device, the second end of the power module is connected to the logic control module, the third end of the power module is connected to the first end of the high-voltage startup module, and the second end of the high-voltage startup module is connected to the source terminal of the GaN power tube.

4. The control device according to claim 3, wherein: The high-voltage startup module includes: a first diode, a first resistor and a first switch connected in series, wherein the first diode and the first switch are respectively connected to the power supply terminal of the control device and the source terminal of the GaN power tube, and the first switch is turned on or off according to the power supply voltage from the power module.

5. The control device according to claim 1, wherein: The first input terminal of the logic control module is connected to the feedback terminal, and the second input terminal of the logic control module is connected to the sampling terminal; The input end of the driving module is connected to the output end of the logic control module; The gate terminal of the MOSFET is connected to the output terminal of the driving module, and the source terminal of the MOSFET is connected to the sampling terminal; The source terminal of the GaN power tube is connected to the drain terminal of the MOSFET, and the drain terminal of the GaN power tube serves as the output terminal of the control device; and The first end of the driving and regulating module is connected to the gate end of the GaN power tube, and the second end of the driving and regulating module is connected to the source end of the MOSFET.

6. The control device according to claim 5, wherein: The driving adjustment module includes: a second resistor, a second diode and a third resistor, Among them, the first end of the second resistor is connected to the gate terminal of the GaN power tube, the second end of the second resistor is connected to the source terminal of the MOSFET, the first end of the second diode is connected to the gate terminal of the GaN power tube, the second end of the second diode is connected to the first end of the third resistor, and the second end of the third resistor is connected to the source terminal of the MOSFET, wherein the second resistor and the third resistor each have a fixed resistance.

7. The control device according to claim 5, wherein: The driving adjustment module includes: a first adjustable resistance branch, a second diode and a second adjustable resistance branch. Wherein, the first end of the first adjustable resistance branch is connected to the gate terminal of the GaN power tube, the second end of the first adjustable resistance branch is connected to the source terminal of the MOSFET, the first end of the second diode is connected to the gate terminal of the GaN power tube, the second end of the second diode is connected to the first end of the second adjustable resistance branch, and the second end of the second adjustable resistance branch is connected to the source terminal of the MOSFET, The first adjustable resistance branch adjusts the first adjustable resistance of the first adjustable resistance branch in response to a first switch control signal from the logic control module, and the second adjustable resistance branch adjusts the second adjustable resistance of the second adjustable resistance branch in response to a second switch control signal from the logic control module.

8. The control device according to claim 7, wherein: The first adjustable resistance branch comprises: at least two fourth resistors connected in series and a switch connected in parallel with each of the at least two fourth resistors, wherein the switch connected in parallel with each of the at least two fourth resistors is independently controlled to be turned on or off in response to the first switch control signal from the logic control module; The second adjustable resistance branch includes: at least two fifth resistors connected in series and a switch connected in parallel with each of the at least two fifth resistors, wherein the switch connected in parallel with each of the at least two fifth resistors is independently controlled to be turned on or off in response to the second switch control signal from the logic control module.

9. The control device according to any one of claims 1 to 8, further comprising a voltage clamping circuit configured to clamp the voltage at the source end of the GaN power tube to a clamping voltage at the moment when the GaN power tube is turned off, wherein: The voltage clamping circuit is connected to the source terminal of the GaN power tube.

10. The control device according to claim 9, wherein: The voltage clamping circuit includes: a Zener diode, a fifth resistor, a sixth resistor, a seventh resistor and a third power tube. Wherein, the first end of the Zener diode is connected to the source end of the GaN power tube, the second end of the Zener diode is connected to the first end of the fifth resistor, the second end of the first resistor is connected to the first end of the fourth resistor, and the second end of the sixth resistor is grounded; The first end of the seventh resistor is connected to the source end of the GaN power tube, the second end of the seventh resistor is connected to the drain end of the third power tube, the gate end of the third power tube is connected to the connection point of the second end of the fifth resistor and the first end of the sixth resistor, and the source end of the third power is grounded.

11. The control device according to claim 5, wherein: The logic control module includes: an eighth resistor, a ninth resistor, a comparator and an SR trigger, Wherein, a first end of the eighth resistor is connected to the feedback terminal, a second end of the eighth resistor is connected to a first end of the ninth resistor, and a second end of the ninth resistor is grounded; The positive input terminal of the comparator is connected to a connection point between the second end of the eighth resistor and the first end of the ninth resistor, the negative input terminal of the comparator is connected to the sampling terminal, and The first input terminal of the SR trigger receives an oscillation signal generated by an oscillator, the second input terminal of the trigger is connected to the output terminal of the comparator, and the output terminal of the SR trigger is connected to the driving module.

12. The control device according to claim 1, wherein: The GaN power tube is a depletion-type GaN power tube.

13. A switching power supply comprising: A control device according to any one of claims 1 to 12.

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