Method for using direct drive-based depletion-mode power switch transistor in energy conversion circuit

Abstract

The present invention relates to a method for using a direct drive-based depletion-mode power switch transistor in an energy conversion circuit. A low-side positive voltage driver is connected to the gate of an enhancement-mode low-voltage power switch transistor Q2; the output end of a current detection unit is connected to the input end of a digital controller, and the input end of the current detection unit is connected to the midpoint of the connection between the source of a depletion-mode high-voltage power switch transistor Q1 and the drain of the enhancement-mode low-voltage power switch transistor Q2; at the same time, the output end of the digital controller is separately connected to the input end of a high-side negative voltage driver and the input end of the low-side positive voltage driver; the current detection unit feeds back currents of the depletion-mode high-voltage power switch transistor Q1 and the enhancement-mode low-voltage power switch transistor Q2 in a normal working process to the digital controller for overcurrent protection for the depletion-mode high-voltage power switch transistor Q1 and the enhancement-mode low-voltage power switch transistor Q2. The present invention overcomes the failure safety problem caused by overcurrent burnout during application.

Description

Method for using depletion-mode power switching transistor based on direct drive in energy conversion circuit TECHNICAL FIELD

[0001] The present application relates to the field of power electronics, and more particularly, to a method for using depletion-mode power switching transistor based on direct drive in energy conversion circuit. BACKGROUND

[0002] The core component of power electronic converters is power transistor, which realizes energy conversion through high-speed switching. It is widely used in energy systems, computer systems, aerospace, military fields, etc., and is closely related to people's daily life.

[0003] At present, power semiconductor devices still mainly use silicon-based materials (Si). However, due to its inherent characteristics, silicon-based materials are difficult to meet the growing demand for power density. In contrast, wide-bandgap semiconductor devices (such as gallium nitride GaN and silicon carbide SiC) have significant advantages, including higher withstand voltage level, lower on-resistance and faster switching speed. Make it very advantageous in high-efficiency energy conversion, high-frequency switching and high-voltage applications. In the application process, depletion-mode devices in wide-bandgap semiconductor devices need negative voltage drive. If the gate drive is out of control, the device will always be in the on state, which may cause circuit short circuit and failure safety problems. Therefore, safe driving of depletion-mode devices becomes a key challenge.

[0004] The driving mode of depletion-mode transistor includes indirect driving and direct driving. In indirect driving, depletion-mode transistor and enhancement-mode low-voltage transistor form a common gate source (Cascode) structure, and depletion-mode device is driven by controlling enhancement-mode device. However, silicon-based enhancement-mode transistor limits the switching frequency, which cannot fully exert the high-frequency advantage of wide-bandgap semiconductor.

[0005] In direct driving, the source of depletion-mode transistor is connected in series with the drain of enhancement-mode low-voltage transistor, and the two devices are independently driven to realize direct driving. During operation, the enhancement-mode transistor is continuously turned on, and the driving signal directly controls the switching state of the depletion-mode transistor. Enhancement-mode transistor does not participate in switching operation, so switching speed and frequency are not affected, and the advantage of depletion-mode transistor can be fully exerted.

[0006] At present, the direct driving method adopts integrated design, which packages depletion-mode power device, enhancement-mode low-voltage power transistor, boost-buck controller, digital logic circuit and push-pull driving circuit together. This method realizes high system stability through complex structure design. However, this integrated application process cannot select power devices by itself, nor can it design driving circuit by itself, thereby reducing the flexibility of application, and its limitation is obvious.

[0007] Another direct drive method is to use a peripheral circuit to control the depletion type and enhancement type devices through two branch circuits with a single drive signal. One branch converts the drive signal into negative voltage for controlling the switching of the depletion type device; the other branch delays the drive signal to control the continuous conduction of the enhancement type low voltage transistor. This method can achieve direct drive. However, since the same signal is used to control the two devices, the control process is not accurate enough. Timing control is prone to problems during power-up and power-down, causing the devices to work out of sync. This may cause short circuits and damage to the devices.

[0008] In view of the current direct drive method, there are problems such as complex structure, high design difficulty, poor flexibility and risk of cooperative work. Therefore, a new energy conversion circuit using method based on direct drive depletion type power switch transistor is needed.

[0009] SUMMARY

[0010] The present application overcomes the above-mentioned defects in the prior art and provides a method for using a depletion type power switch transistor based on direct drive in an energy conversion circuit, which improves safety performance.

[0011] To solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0012] A method for using a depletion type power switch transistor based on direct drive in an energy conversion circuit, the direct drive circuit comprising: a high-side negative voltage driver and a low-side positive voltage driver, a depletion type high-voltage power switch transistor Q1, an enhancement type low-voltage power switch transistor Q2, a current detection unit, and a digital controller; the high-side negative voltage driver is connected to the gate of the depletion type high-voltage power switch transistor Q1; the low-side positive voltage driver is connected to the gate of the enhancement type low-voltage power switch transistor Q2; the output of the current detection unit is connected to the input of the digital controller, and the input of the current detection unit is connected to the middle position of the connection between the source of the depletion type high-voltage power switch transistor Q1 and the drain of the enhancement type low-voltage power switch transistor Q2; at the same time, the output of the digital controller is connected to the input of the high-side negative voltage driver and the input of the low-side positive voltage driver, respectively; the high-side negative voltage driver converts the drive level signal generated by the digital controller to realize negative voltage drive of the depletion type high-voltage power switch transistor Q1; the low-side positive voltage driver converts the level signal of the digital controller to realize positive voltage drive of the enhancement type low-voltage power switch transistor Q2; the current detection unit feeds back the current of the depletion type high-voltage power switch transistor Q1 and the enhancement type low-voltage power switch transistor Q2 during normal operation to the digital controller for overcurrent protection of the depletion type high-voltage power switch transistor Q1 and the enhancement type low-voltage power switch transistor Q2.

[0013] According to the above technical means, the application directly drives the depletion mode power field effect transistor device from the safety requirements and control requirements of actual power conversion applications, the existing integrated direct drive cannot select higher power depletion mode power devices by itself, the direct drive constructed by the peripheral circuit has the problem of incoordination and short circuit due to the inaccurate control timing, and there is no overcurrent detection part between the depletion mode high-voltage power switch transistor Q1 and the enhancement mode low-voltage power switch transistor Q2, which cannot obtain the current flowing through the depletion mode high-voltage power switch transistor Q1 in the normal working process, and the transistor is burned due to the overcurrent of the device when the short circuit risk occurs. The application adds a current detection unit of the depletion mode high-voltage power switch transistor Q1, which can accurately control the power-on timing of the depletion mode high-voltage power switch transistor Q1 and the enhancement mode low-voltage power switch transistor Q2, and can freely select higher power depletion mode power devices. The performance of the depletion mode power field effect transistor can be fully utilized, and a protection mode that can meet the overcurrent protection of the device and reduce the risk of device failure.

[0014] Further, the high-side negative voltage driver includes a positive voltage driver and a charge pump circuit connected with an output end of the positive voltage driver, the charge pump circuit is composed of a capacitor C1 and a diode D1 in parallel; a negative voltage appears at the cathode of the diode D1 after the positive voltage driver inputs a plurality of pulses, so as to realize negative voltage driving. The direct drive of the depletion mode power switch transistor can greatly simplify the complexity of the drive circuit and improve the switching frequency of the depletion mode high-voltage power switch transistor Q1 from the control requirements of the actual circuit.

[0015] Further, the depletion mode high-voltage power switch transistor Q1 and the enhancement mode low-voltage power switch transistor Q2 each have a gate, a drain and a source; the source of the depletion mode high-voltage power switch transistor Q1 is connected with the drain of the enhancement mode low-voltage power switch transistor Q2.

[0016] Further, in the use process, if the depletion mode high-voltage power switch transistor Q1 has an overcurrent behavior in the normal working process, a signal is sent to the digital controller by the current detection unit, then the digital controller transmits a low-level signal through the low-side low-voltage driver to make the enhancement mode low-voltage power switch transistor Q2 close; then, the digital controller stops transmitting the pulse width modulation signal to the depletion mode high-voltage power switch transistor Q1, and the gate-source voltage of the depletion mode high-voltage power switch transistor Q1 gradually decreases to the off voltage of the depletion mode high-voltage power switch transistor Q1, so as to achieve the overcurrent protection of the depletion mode high-voltage power switch transistor Q1.

[0017] Further, during normal power-up, the digital controller outputs low-level signals to the high-side negative voltage driver and the low-side positive voltage driver for level conversion, ensuring that the depletion-mode high-voltage power switch transistor Q1 and the enhancement-mode low-voltage power switch transistor Q2 are both in the off state.

[0018] Further, during normal power-up, the drain of the depletion-mode high-voltage power switch transistor Q1 is applied with high voltage, and the gate-source voltage of the depletion-mode high-voltage power switch transistor Q1 gradually decreases to the off voltage of the depletion-mode high-voltage power switch transistor Q1. After the depletion-mode high-voltage power switch transistor Q1 is completely turned off, the digital controller outputs a high-level signal to the low-side positive voltage driver to completely turn on the enhancement-mode low-voltage power switch transistor Q2.

[0019] Further, after the depletion-mode high-voltage power switch transistor Q1 is completely turned off, the enhancement-mode low-voltage power switch transistor Q2 is completely turned on, and the digital controller outputs continuous pulse width modulation signals to the high-side negative voltage driver to turn on and turn off the depletion-mode high-voltage power switch transistor Q1, thereby achieving energy conversion.

[0020] Further, during the shutdown stage of the depletion-mode high-voltage power switch transistor Q1 in the normal working process during use, the digital controller outputs a low-level signal to the low-side positive voltage driver to turn off the enhancement-mode low-voltage power switch transistor Q2. Subsequently, the digital controller stops transmitting pulse width modulation signals to the depletion-mode high-voltage power switch transistor Q1 to completely turn off the depletion-mode high-voltage power switch transistor Q1, thereby achieving safe shutdown.

[0021] Further, the power-up control sequence includes: power-up start, the digital controller generates low-level signals to the high-side negative voltage driver and the low-side positive voltage driver, and the level conversion by the high-side negative voltage driver and the low-side positive voltage driver makes the depletion-mode high-voltage power switch transistor Q1 and the enhancement-mode low-voltage power switch transistor Q2 both in the off state; after the depletion-mode high-voltage power switch transistor Q1 is completely turned off, the digital controller generates a high-level signal to the low-side positive voltage driver for level conversion to turn on the enhancement-mode low-voltage power switch transistor Q2, thereby realizing the direct driving turn-on process of the depletion-mode high-voltage power switch transistor Q1; then, the digital controller generates an arbitrary period pulse width modulation signal to the high-side negative voltage driver to further realize the turn-on and turn-off of the depletion-mode high-voltage power switch transistor Q1 and the enhancement-mode low-voltage power switch transistor Q2.

[0022] Further, the power-off control timing includes: when the direct drive circuit is in the complete operation process, the depletion-mode high-voltage power switch transistor Q1 is in the normal switching process, and the enhancement-mode low-voltage power switch transistor Q2 is in the fully on state; at this time, the digital controller generates a low-level signal to realize the turn-off of the enhancement-mode low-voltage power switch transistor Q2 through the low-side positive voltage driver. Subsequently, the digital controller turns off the output of the pulse width modulation signal and outputs a low-level signal to realize the turn-off of the depletion-mode high-voltage power switch transistor Q1 through the high-side negative voltage driver; thereby realizing the shutdown process of the direct drive.

[0023] Further, the overcurrent protection control timing includes: when the direct drive circuit is in the complete operation process, the depletion-mode high-voltage power switch transistor Q1 is in the normal switching process, and the enhancement-mode low-voltage power switch transistor Q2 is in the fully on state; the current detection unit collects and feeds back the current flowing through the depletion-mode high-voltage power switch transistor Q1 and the enhancement-mode low-voltage power switch transistor Q2 to the digital controller, when the digital controller judges that the current flowing through the depletion-mode high-voltage power switch transistor Q1 exceeds the rated working current of the device, the digital controller generates a low-level signal to realize the turn-off of the enhancement-mode low-voltage power switch transistor Q2 through the low-side positive voltage driver. Subsequently, the digital controller turns off the pulse width modulation signal and generates a low-level signal to realize the turn-off of the depletion-mode high-voltage power switch transistor Q1 through the high-side negative voltage driver; subsequently. Further, the overcurrent protection of the depletion-mode high-voltage power switch transistor Q1 is realized.

[0024] Compared with the prior art, the beneficial effects are: the use method of the depletion-mode power switch transistor based on direct drive provided by the application fully develops the performance of the depletion-mode power field effect transistor device and meets the failure safety demand of the overcurrent of the device, and overcomes the failure safety problem of overcurrent burnout of the existing depletion-mode device direct drive application scheme. BRIEF DESCRIPTION OF DRAWINGS

[0025] Fig. 1 is a topology structure of a direct drive circuit protection mode based on a depletion-mode power field effect transistor in an embodiment of the application.

[0026] Fig. 2 is a negative voltage driver circuit structure diagram in an embodiment of the application.

[0027] Fig. 3 is a timing control diagram when starting the machine in an embodiment of the application.

[0028] Fig. 4 is a timing control diagram when shutting down in an embodiment of the application.

[0029] Fig. 5 is a timing control diagram of overcurrent protection in an embodiment of the application. DETAILED DESCRIPTION

[0030] With reference to the accompanying drawings, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. The present application is described in one of the embodiments in combination with the specific implementation manners. In the embodiments, the accompanying drawings are only used for example description, and the representation is only a schematic diagram, rather than a real object diagram, and cannot be understood as a limitation on the present application. In order to better illustrate the embodiments of the present application, some components in the drawings are omitted, enlarged or reduced, and do not represent the size of the actual product. It is understandable for those skilled in the art that some well-known structures and their descriptions in the drawings can be omitted.

[0031] In the description of the present application, it should be understood that the orientation or position relationship indicated by the terms "upper", "lower", "left", "right" and the like is based on the orientation or position relationship shown in the drawings, and is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element indicated must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the position relationship in the drawings are only used for example description, and cannot be understood as a limitation on the present application. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances. In addition, if the present application has a description of "first", "second" and the like in the embodiments, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the meaning of "and / or" appearing throughout the text is that it includes three parallel schemes, for example, "A and / or B" includes A scheme, or B scheme, or A and B schemes are satisfied at the same time.

[0032] Embodiment 1:

[0033] As shown in Figure 1, a method for using a direct drive depletion mode power switch transistor in an energy conversion circuit, the direct drive circuit comprising: a high side negative voltage driver and a low side positive voltage driver, a depletion mode high voltage power switch transistor Q1, an enhancement mode low voltage power switch transistor Q2, a current detection unit, a digital controller; the high side negative voltage driver is connected to the gate of the depletion mode high voltage power switch transistor Q1; the low side positive voltage driver is connected to the gate of the enhancement mode low voltage power switch transistor Q2; the output of the current detection unit is connected to the input of the digital controller, and the input of the current detection unit is connected to the middle position of the connection between the source of the depletion mode high voltage power switch transistor Q1 and the drain of the enhancement mode low voltage power switch transistor Q2; at the same time, the output of the digital controller is connected to the input of the high side negative voltage driver and the input of the low side positive voltage driver respectively; the high side negative voltage driver converts the driving level signal generated by the digital controller to realize the negative voltage drive of the depletion mode high voltage power switch transistor Q1; the low side positive voltage driver converts the level signal of the digital controller to realize the positive voltage drive of the enhancement mode low voltage power switch transistor Q2; the current detection unit feeds back the current of the depletion mode high voltage power switch transistor Q1 and the enhancement mode low voltage power switch transistor Q2 in the normal working process to the digital controller for overcurrent protection of the depletion mode high voltage power switch transistor Q1.

[0034] Specifically, the depletion mode high voltage power switch transistor Q1 and the enhancement mode low voltage power switch transistor Q2 each have a gate, a drain and a source; the source of the depletion mode high voltage power switch transistor Q1 is connected to the drain of the enhancement mode low voltage power switch transistor Q2.

[0035] In use, if the depletion mode high voltage power switch transistor Q1 occurs overcurrent behavior in the normal working process, the current detection unit sends a signal to the digital controller, and then the digital controller transmits a low level signal through the low side low voltage driver to make the enhancement mode low voltage power switch transistor Q2 close; then, the digital controller stops transmitting the pulse width modulation signal to the depletion mode high voltage power switch transistor Q1, so as to achieve overcurrent protection of the depletion mode high voltage power switch transistor Q1.

[0036] When normally powered on, the digital controller outputs a low level signal through the high side positive voltage driver and the low side positive voltage driver for level conversion; to ensure that the depletion mode high voltage power switch transistor Q1 and the enhancement mode low voltage power switch transistor Q2 are both in the closed state.

[0037] When normally powered on, the drain of the depletion mode high voltage power switch transistor Q1 is applied with high voltage, and after the gate of the depletion mode high voltage power switch transistor Q1 is completely closed, the digital controller outputs a high level signal through the low side positive voltage driver to make the enhancement mode low voltage power switch transistor Q2 completely conductive.

[0038] In this embodiment, after the drain of the depletion-mode high-voltage power switch transistor Q1 is applied with high voltage and its gate is completely closed, the enhancement-mode low-voltage power switch transistor Q2 is completely turned on, and the digital controller sends continuous pulse width modulation signals to realize the turn-on and turn-off of the depletion-mode high-voltage power switch transistor Q1 through the high-side negative voltage driver, so as to realize the conversion of energy.

[0039] In this embodiment, during the shutdown stage of the depletion-mode high-voltage power switch transistor Q1 in the normal working process, the digital controller sends a low-level signal to the low-side positive voltage driver to make the enhancement-mode low-voltage power switch transistor Q2 turn off; then, the digital controller stops sending pulse width modulation signals to the depletion-mode high-voltage power switch transistor Q1 to make it completely turn off, so as to achieve the requirement of safe shutdown.

[0040] Working principle:

[0041] As shown in FIG. 1, during the normal power-on working process of the depletion-mode high-voltage power switch transistor Q1, the digital controller sends a low-level signal to the high-side negative voltage driver and the low-side positive voltage driver to ensure the turn-off of the depletion-mode high-voltage power switch transistor Q1 and the enhancement-mode low-voltage power switch transistor Q2. After the turn-off of the depletion-mode high-voltage power switch transistor Q1 is completed, the digital controller sends a high-level signal through the low-side positive voltage driver to ensure the complete turn-on of the enhancement-mode low-voltage power switch transistor Q2. Then, the digital controller continuously generates continuous pulse width modulation signals to realize the normal switching of the depletion-mode high-voltage power switch transistor Q1 through the high-side negative voltage driver.

[0042] During the normal power-off working process of the device, the digital controller first generates a low level through the low-side driver to turn off the enhancement-mode low-voltage power switch transistor Q2. Then, the digital controller turns off the output of the pulse width modulation signal to realize the safe turn-off of the depletion-mode high-voltage power switch transistor Q1.

[0043] During the normal overcurrent protection working process of the device, the current detection unit continuously obtains the current flowing through the depletion-mode high-voltage power switch transistor Q1 and feeds back to the digital controller. The digital controller judges whether to perform overcurrent protection of the device according to the feedback current result. When the current feedback result is within the rated working current range of the device, the protection of the device is not performed. When the rated current of the device is exceeded, the digital controller first generates a low level through the low-side driver to turn off the enhancement-mode low-voltage power switch transistor Q2. Then, the digital controller turns off the output of the pulse width modulation signal to realize the overcurrent protection function of the power device.

[0044] The beneficial effects of the above technical solution are: from the safety requirements and control requirements of the direct driving of the depletion mode power field effect transistor device in the actual circuit, there is no overcurrent detection part between the depletion mode high-voltage power switch transistor Q1 and the enhancement mode low-voltage power switch transistor Q2, which cannot obtain the flow current of the depletion mode high-voltage power switch transistor Q1 in the normal working process, the overcurrent of the device when the short circuit risk occurs, and the burning of the transistor caused by the overcurrent. In the proposed use mode, the current detection unit of the depletion mode high-voltage power switch transistor Q1 is added, and the digital controller can accurately control the power-on of the depletion mode high-voltage power switch transistor Q1 and the enhancement mode low-voltage power switch transistor Q2. The performance of the depletion mode gallium nitride power field effect transistor can be fully utilized, and a protection mode that can meet the overcurrent protection of the device and reduce the risk of device failure.

[0045] Embodiment 2

[0046] The other structures of this embodiment are the same as those of Embodiment 1, except that the high-side negative voltage driver includes a positive voltage driver and a charge pump circuit connected to the output end of the positive voltage driver, the charge pump circuit is composed of a capacitor C1 and a diode D1 in parallel; a negative voltage appears at the cathode of the diode D1 after the positive voltage driver inputs a plurality of pulses, thereby realizing negative voltage driving.

[0047] The beneficial effects of the above technology are: from the control requirements of the direct driving of the depletion mode power switch transistor in the actual circuit, the complexity of the driving circuit can be greatly simplified, and the switching frequency of the depletion mode high-voltage power switch transistor Q1 can be improved.

[0048] Embodiment 3

[0049] This embodiment provides the control timing of the direct driving shown in Embodiment 1, as shown in FIG. 3, the normal power-on control timing includes: system power-on starts, the digital controller generates a low-level signal as shown in FIG. 3 ①, the depletion mode high-voltage power switch transistor Q1 is in the on state, and the enhancement mode low-voltage power switch transistor Q2 is in the off state. Then the controller generates a plurality of pulses as shown in FIG. 3 ② to realize the turn-off of the depletion mode high-voltage power switch transistor Q1 through the negative voltage driving shown in FIG. 2. Then after waiting for a time interval as shown in FIG. 3 ③, the digital controller sends a high-level signal to the low-side driver to open the enhancement mode low-voltage power switch transistor Q2, thereby realizing the opening process of the direct driving of the depletion mode high-voltage power switch transistor Q1. Finally, after FIG. 3 ④, the digital controller can generate a pulse width modulation signal with any period to make the whole system enter the working state through the negative voltage driving as shown in FIG. 2.

[0050] The control timing of the system power down is that when the system is in the complete running process, as shown in ① of FIG. 4, the depletion mode high-voltage power switch transistor Q1 is in the normal switching process, and the enhancement mode low-voltage power switch transistor Q2 is in the completely on state. In order to make the device safe power down in the normal working process, as shown in ② of FIG. 4, the digital controller generates a low-level signal to realize the turn-off of the enhancement mode low-voltage power switch transistor Q2 through the low-side positive voltage driver. Then in ③ of FIG. 4, the digital controller stops outputting the pulse width modulation signal and outputs a low level, and the gate-source voltage of the depletion mode high-voltage power switch transistor Q1 gradually decreases to the turn-off voltage of Q1. Thus, the turn-off process of the depletion mode high-voltage power switch transistor Q1 directly driven is realized.

[0051] The timing of the system overcurrent protection control is that when the system is in the complete running process, as shown in ① of FIG. 5, the depletion mode high-voltage power switch transistor Q1 is in the normal switching process, and the enhancement mode low-voltage power switch transistor Q2 is in the completely on state. The current detection unit collects and feeds back the current flowing through the depletion mode high-voltage power switch transistor Q1 and the enhancement mode low-voltage power switch transistor Q2 to the digital controller, and when the digital controller judges that the current flowing through the depletion mode high-voltage power switch transistor Q1 exceeds the rated working current of the device, a high-level signal is generated at the overcurrent time as shown in ② of FIG. 5. When the digital controller receives the overcurrent signal, a low-level signal is immediately generated to realize the turn-off of the enhancement mode low-voltage power switch transistor Q2 through the low-side positive voltage driver as shown in ② of FIG. 5. Then in ③ of FIG. 5, the digital controller stops outputting the pulse width modulation signal and outputs a continuous low-level signal, and the gate-source voltage of the depletion mode high-voltage power switch transistor Q1 gradually decreases to the turn-off voltage of Q1. Thus, the overcurrent protection process of the depletion mode high-voltage gallium nitride power transistor is realized.

[0052] The above technical solution has the beneficial effects that the depletion mode power field effect transistor device performance can be fully utilized, and the circuit structure meeting the failure safety requirement is obtained, the existing depletion mode device application scheme has the problems of failure safety, switch characteristics affected by the series silicon-based device, existence of capacitance matching and reverse recovery time, switch loss is reduced, and the performance of the depletion mode power field effect transistor device is fully released.

[0053] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine the different embodiments or examples described in the specification and the features of the different embodiments or examples without contradiction, and the combination is within the scope of the present application.

[0054] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the implementation manner of the present application. Based on the above description, those skilled in the art can make other different forms of changes or variations. Here, it is not necessary and impossible to enumerate all the implementation manners. Any modification, equivalent replacement and improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.

Claims

1. A method of using a direct drive depletion mode power switching transistor in an energy conversion circuit, characterized by, The application relates to a high-voltage power switch transistor and a low-voltage power switch transistor, and belongs to the field of power electronic technology. The application relates to a high-voltage power switch transistor and a low-voltage power switch transistor, and belongs to the field of power electronic technology.

2. The method of using a direct drive based depletion mode power switching transistor in an energy conversion circuit according to claim 1, wherein, The application relates to a high-voltage power switch transistor and a low-voltage power switch transistor, and belongs to the field of power electronic technology.

3. The method of using a direct drive based depletion mode power switching transistor in an energy conversion circuit according to claim 1, wherein, The application relates to a high-voltage power switch transistor and a low-voltage power switch transistor, and belongs to the field of power electronic technology.

4. The method of using a direct drive based depletion mode power switching transistor in an energy conversion circuit according to claim 1, wherein, The application relates to a high-voltage power switch transistor and a low-voltage power switch transistor, and belongs to the field of power electronic technology.

5. The method of using a direct drive based depletion mode power switching transistor in an energy conversion circuit according to claim 1, wherein, The application relates to a high-voltage power switch transistor and a low-voltage power switch transistor, and belongs to the field of power electronic technology.

6. The method of using a direct drive based depletion mode power switching transistor in an energy conversion circuit according to claim 1, wherein, The application relates to a high-voltage power switch transistor and a low-voltage power switch transistor, and belongs to the field of power electronic technology.

7. The method of using a direct drive based depletion mode power switching transistor in an energy conversion circuit according to claim 1, wherein, In the process of use, the depletion-mode high-voltage power switch transistor Q1 is turned off in the normal working process, and a low-level signal is sent by the digital controller through the low-side positive voltage driver to turn off the enhancement-mode low-voltage power switch transistor Q2; after waiting for a certain period of time, the digital controller stops sending the pulse width modulation signal to the depletion-mode high-voltage power switch transistor Q1 to completely turn off the depletion-mode high-voltage power switch transistor Q1, so as to achieve the requirement of safe shutdown.

8. Method of using a direct-drive based depletion mode power switching transistor according to any one of claims 1 to 7 in an energy conversion circuit, characterized in that, The power-on control timing sequence includes: power-on start, the digital controller generates a low-level signal to the high-side negative voltage driver and the low-side positive voltage driver, and the depletion-mode high-voltage power switch transistor Q1 and the enhancement-mode low-voltage power switch transistor Q2 are both in the off state through the level conversion of the high-side negative voltage driver and the low-side positive voltage driver; after the depletion-mode high-voltage power switch transistor Q1 is completely turned off, the digital controller generates a high-level signal through the low-side positive voltage driver to perform level conversion and turn on the enhancement-mode low-voltage power switch transistor Q2, so as to realize the direct driving opening process of the depletion-mode high-voltage power switch transistor Q1; then, the digital controller generates an arbitrary period pulse width modulation signal to the high-side negative voltage driver to realize the opening and closing of the depletion-mode high-voltage power switch transistor Q1.

9. Method of using a direct-drive based depletion mode power switching transistor according to any one of claims 1 to 7 in an energy conversion circuit, characterized in that, The power-off control timing sequence includes: when the direct driving circuit is in the complete running process, the depletion-mode high-voltage power switch transistor Q1 is in the normal switching process, and the enhancement-mode low-voltage power switch transistor Q2 is in the completely conductive state; at this time, the digital controller generates a low-level signal through the low-side positive voltage driver to realize the turn-off of the enhancement-mode low-voltage power switch transistor Q2; then, the digital controller stops generating the pulse width modulation signal of the high-side negative voltage driver, the gate-source voltage of the depletion-mode high-voltage power switch transistor Q1 is gradually raised to realize the turn-off of the depletion-mode high-voltage power switch transistor Q1, so as to realize the closing process of the direct driving circuit.

10. A method of using a direct-drive depletion-mode power switching transistor according to any one of claims 1 to 7 in an energy conversion circuit, characterized in that, The over-current protection control timing sequence includes: when the direct driving circuit is in the complete running process, the depletion-mode high-voltage power switch transistor Q1 is in the normal switching process, and the enhancement-mode low-voltage power switch transistor Q2 is in the completely conductive state; the current detection unit collects and feeds back the current flowing through the depletion-mode high-voltage power switch transistor Q1 and the enhancement-mode low-voltage power switch transistor Q2 to the digital controller; when the digital controller judges that the current flowing through the depletion-mode high-voltage power switch transistor Q1 exceeds the rated working current of the device, the digital controller generates a low-level signal through the low-side negative voltage driver to realize the turn-off of the enhancement-mode low-voltage power switch transistor Q2; the digital controller stops generating the pulse width modulation signal of the high-side negative voltage driver, the gate-source voltage of the depletion-mode high-voltage power switch transistor Q1 is gradually raised to realize the turn-off of the depletion-mode high-voltage power switch transistor Q1, so as to realize the over-current protection of the direct driving circuit.

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