Gate driver circuit for current-controlled switching element

Abstract

The invention relates to a gate driver circuit for a current-controlled switching element. An apparatus for controlling a current-controlled switching element includes an output node, a current driver circuit, and a detection circuit arrangement. The output node is configured to be electrically coupled to a control node of the current-controlled switching element. The current control type switching element is configured to change from operating in an off state to operating in an on state when a charge supplied to the control node causes a voltage at the control node to be greater than an activation threshold. The current driver circuit is configured to output an activation current to the output node in response to a switching signal indicating that the current control type switching element changes from an off state to an on state. The detection circuitry is configured to detect when a switching event has occurred based on the voltage at the control node while the current driver circuit outputs the activation current.

Description

Technical Field

[0001] The present disclosure relates to an apparatus for controlling a current-controlled switching element, such as a gate injection transistor (GIT) switching element. Background Art

[0002] The circuit can be configured to control the current-controlled switching element. For example, the circuit can control the current-controlled switching element to operate in an on-state, thereby allowing current to flow through the current-controlled switching element, and control the current-controlled switching element to operate in an off-state, thereby preventing current from flowing through the current-controlled switching element. Summary of the Invention

[0003] The present disclosure describes techniques, devices, and systems for controlling current-controlled switching elements (e.g., gate injection transistor (GIT) switching elements). According to the techniques of the present disclosure, a device can be configured to detect when a switching event has occurred based on a voltage at a control node of the current-controlled switching element while a current driver circuit outputs an activation current. In this example, the device can output a holding current to an output node when a switching event has occurred. The activation current can be sufficient to supply charge to the control node, thereby causing the voltage at the control node to be greater than an activation threshold. The holding current can be sufficient to charge the control node, thereby maintaining the voltage at the control node continuously greater than the activation threshold. In this way, the device can reduce the amount of power used to switch the current-controlled switching element compared to a device using a preconfigured time. In addition, reducing the power loss of switching the current-controlled switching element can help reduce the waste heat generated by the current-controlled switching element, which can help increase the reliability of the current-controlled switching element and / or help reduce the amount of heat dissipation required by the system.

[0004] In some examples, a device for controlling a current-controlled switching element includes an output node configured to be electrically coupled to a control node of the current-controlled switching element. The current-controlled switching element is configured to change from operating in an off state to operating in an on state when a charge supplied to the control node causes a voltage at the control node to be greater than an activation threshold. The device also includes a current driver circuit configured to output an activation current to the output node in response to a switching signal, the switching signal instructing the current-controlled switching element to change from an off state to an on state. The activation current is configured to supply charge to the control node, thereby causing the voltage at the control node to be greater than the activation threshold. The device also includes a detection circuit device configured to detect when a switching event has occurred based on the voltage at the control node while the current driver circuit outputs the activation current. The current driver circuit is further configured to output a holding current to the output node when the detection circuit device has detected that the switching event has occurred.

[0005] In some examples, a method includes determining a switching signal that instructs an operating current-controlled switching element to change from an off-state to an on-state. The current-controlled switching element is configured to change from operating in the off-state to operating in the on-state when a charge supplied to a control node of the current-controlled switching element causes a voltage at the control node to be greater than an activation threshold. In response to the switching signal that instructs the operating current-controlled switching element to change from an off-state to an on-state, the method includes outputting an activation current to an output node that is electrically coupled to the control node. The activation current is configured to supply charge to the control node, thereby causing the voltage at the control node to be greater than the activation threshold. The method also includes detecting when a switching event has occurred based on the voltage at the control node while outputting the activation current, and outputting a holding current to the output node when the switching event is detected to have occurred.

[0006] In some examples, a system includes a current-controlled switching element configured to change from operating in an off-state to operating in an on-state when a charge supplied to a control node of the current-controlled switching element causes a voltage at the control node to be greater than an activation threshold. The system also includes a driver circuit device and a current driver circuit. The driver circuit includes an output node configured to be electrically coupled to the control node of the current-controlled switching element. The current driver circuit is configured to output an activation current to the output node in response to a switching signal instructing the current-controlled switching element to change from an off-state to an on-state. The activation current is configured to supply charge to the control node, thereby causing the voltage at the control node to be greater than the activation threshold. The driver circuit device also includes a detection circuit device configured to detect when a switching event has occurred based on the voltage at the control node while the current driver circuit is outputting the activation current. The current driver circuit is further configured to output a holding current to the output node when the detection circuit device detects that the switching event has occurred.

[0007] The details of one or more examples are set forth in the accompanying drawings and the description below.Other features, objects, and advantages of the disclosure will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a block diagram illustrating an example system configured for controlling a current-controlled switching element, according to one or more techniques of this disclosure.

[0009] Figure 2 is a graph illustrating example behavior of a current-controlled switching element according to one or more techniques of this disclosure.

[0010] Figure 3is a conceptual diagram of a control current for driving a current-controlled switching element according to one or more techniques of the present disclosure.

[0011] Figure 4 is a block diagram illustrating an example system configured for controlling a current-controlled switching element using a low-current driver circuit and a high-current driver circuit, according to one or more techniques of this disclosure.

[0012] Figure 5 is a diagram illustrating a method of performing a Figure 4 Graphs of an example voltage at a control node and a current at the control node of a current-controlled switching element.

[0013] Figure 6 is a block diagram illustrating an example system configured for controlling a current-controlled switching element using a low-current driver circuit, a high-current driver circuit, and a timer, according to one or more techniques of this disclosure.

[0014] Figure 7 is a diagram illustrating a method of performing a Figure 6 Graphs of an example voltage at a control node and a current at the control node of a current-controlled switching element.

[0015] Figure 8 is a block diagram illustrating an example system configured for controlling a current-controlled switching element using a low-current driver circuit, a high-current driver circuit, a timer, and safety logic, according to one or more techniques of this disclosure.

[0016] Figure 9 is a block diagram illustrating an example system configured for controlling a current-controlled switching element using a low-current driver circuit, a high-current driver circuit, a timer, safety logic, and a voltage monitor, according to one or more techniques of this disclosure.

[0017] Figure 10 is a block diagram illustrating an example system configured for controlling a current-controlled switching element using a low-current driver circuit, a high-current driver circuit, a timer, safety logic, and an event counter, according to one or more techniques of this disclosure.

[0018] Figure 11 is a block diagram illustrating an example system configured for controlling a current-controlled switching element using a low-current driver circuit having first and second resistive components and a high-current driver circuit having a second resistive component, according to one or more techniques of this disclosure.

[0019] Figure 12is a block diagram illustrating an example system configured to control a current-controlled switching element using a low-current driver circuit with a current source, according to one or more techniques of this disclosure.

[0020] Figure 13 is a flow chart for controlling a current-controlled switching element according to one or more techniques of this disclosure. DETAILED DESCRIPTION

[0021] The present disclosure describes techniques, devices, and systems for controlling a current-controlled switching element, such as a gate injection transistor (GIT). For example, a current-controlled switching element may use an activation current to change from an off-state to an on-state. However, maintaining the activation current during the entire time period that the current-controlled switching element is in the on-state may damage the current-controlled switching element. Therefore, some devices may include circuitry that provides an activation current during a preconfigured time and then provides a holding current. In this way, the current-controlled switching element can be changed from an off-state to an on-state without damaging the current-controlled switching element.

[0022] According to the technology of the present disclosure, the driver circuit device can be configured to detect when a switching event has occurred based on the voltage at the control node of the current-controlled switching element while the current driver circuit outputs an activation current. In this example, when the switching event has occurred, the driver circuit device can output a holding current to the output node. The activation current can be sufficient to supply charge to the control node, thereby causing the voltage at the control node to be continuously greater than the activation threshold. The holding current can be sufficient to charge the control node, thereby maintaining the voltage at the control node to be continuously greater than the activation threshold. Compared to devices using pre-configured times, with this approach, the driver circuit device can reduce the amount of power used to switch the current-controlled switching element. In addition, reducing the power loss of switching the current-controlled switching element can help reduce the waste heat generated by the current-controlled switching element, which also helps to increase the reliability of the current-controlled switching element and / or helps to reduce the amount of heat dissipation required by the system.

[0023] In some examples, the driver circuit device may include a circuit configured to cause the driver circuit device to output a holding current instead of an activation current after a threshold amount of time has elapsed since the current-controlled switching element has been in the on state. For example, the driver circuit device may start a timer in response to a switching cycle of a switching signal, the switching signal indicating that the current-controlled switching element has changed from the off state to the on state. In this example, the driver circuit device may output a signal based on the timer. The driver circuit device may be configured to output the holding current when the timer circuit device outputs the signal. In this way, the driver circuit device can help ensure that the activation current is supplied to the current-controlled switching element for no more than the threshold amount of time, which can reduce or eliminate the risk of the activation current damaging the current-controlled switching element.

[0024] In some examples, a driver circuit device may include a low-current driver circuit configured to output a holding current to an output node while a switching signal indicates that a current-controlled switching element is operated in an on-state. In this example, the driver circuit device may further include a high-current driver circuit configured to output a supplementary current to the output node only for a portion of the time when the switching signal indicates that the current-controlled switching element is operated in an on-state, the supplementary current forming an activation current when combined with the holding current output by the low-current driver circuit. In this way, the low-current driver can be implemented to provide a relatively high-precision current at a relatively low switching rate (e.g., a current source), while the high-current driver can be implemented to provide a relatively low-precision current at a relatively high switching rate (e.g., a resistor and a switching element arranged in series), which can reduce the complexity of the driver circuit device and / or reduce the cost of the driver circuit device compared to a system using a single current driver to provide both the activation current and the holding current.

[0025] Figure 1 is a block diagram illustrating an example system 100 configured for controlling a current-controlled switching element 104 , according to one or more techniques of this disclosure. Driver circuitry 102 includes a current driver circuit 112 , a detection circuitry 114 , and an output node 106 .

[0026] The driver circuit device 102 can be configured to control the current-controlled switching element 104 to operate in an on state or an off state. The driver circuit device 102 may include a current driver circuit 112 and a detection circuit device 114. The driver circuit device 102 may include analog circuits. In some examples, the driver circuit device 102 may include a microcontroller on a single integrated circuit that includes a processor core, memory, inputs, and outputs. For example, the driver circuit device 102 may include one or more application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or any other equivalent integrated or discrete logic circuit devices, as well as any combination of such components. The term "processor" or "processing circuit device" may generally refer to any of the above-mentioned logic circuit devices, alone or in combination with other logic circuit devices or any other equivalent circuits. The driver circuit device 102 may be a combination of one or more analog components and one or more digital components.

[0027] The current-controlled switching element 104 can represent a switching element that is configured to be turned on or off based on current. For example, the current-controlled switching element 104 can include a gallium nitride (GaN) switching element. In some examples, the current-controlled switching element 104 can include a gate injection transistor (GIT) switching element. In particular, the current-controlled switching element 104 can refer to a current-controlled GIT including a semiconductor structure formed in GaN. Although the examples described herein may be directed to controlling GIT switching elements for example purposes, the techniques described herein for controlling GIT switching elements can be applied to any switching element that is controlled to operate from an off state to an on state by using an activation current and a holding current. As used herein, a switching element that is controlled to be "on" or operating in an "on state" can refer to a state of a switching element in which the switching element establishes a conductive path connecting a first node (e.g., a drain or collector) and a second node (e.g., a source or emitter). Similarly, a switching element being controlled to be “open” or operating in an “off state” may refer to a state of the switching element in which the switching element does not establish a conductive path connecting a first node and a second node.

[0028] The output node 106 can be configured to be electrically coupled to the control node 108 of the current-controlled switching element 104. The current-controlled switching element 104 can be configured to change from operating in the off state to operating in the on state when the charge supplied to the control node 108 causes the voltage at the control node 108 to be above an activation threshold. For example, the voltage at the control node 108 of the current-controlled switching element 104 responds to the current similarly to a capacitor. The output node 106 can represent a pin of a package (e.g., a chip implementing the driver circuit device 102) to electrically couple the package to the control node 108 of the current-controlled switching element 104. However, in some examples, the output node 106 can represent an internal node of a single package that includes both the driver circuit device 102 and the current-controlled switching element 104.

[0029] The current driver circuit 112 can output an activation current to the output node 106 in response to a switching signal instructing the operating current-controlled switching element 104 to change from an off state to an on state. The activation current can be configured to supply charge to the control node 108 of the current-controlled switching element 104, thereby causing the voltage at the control node 108 to be greater than an activation threshold.

[0030] Detection circuitry 114 can detect when a switching event has occurred based on the voltage at control node 108 while current driver circuit 112 is outputting an activation current. For example, detection circuitry 114 can determine that a switching event has occurred when the voltage at control node 108 exceeds a reference voltage. For example, detection circuitry 114 can include a comparator configured to compare the voltage at control node 108 to a reference voltage. In this example, detection circuitry 114 can detect that a switching event has occurred when the comparator outputs a logic "0" value indicating that the voltage at control node 108 exceeds the reference voltage.

[0031] The current driver circuit 112 can output a holding current to the output node 106 in response to the detection circuitry 114 detecting that a switching event has occurred. The holding current can be sufficient to charge the control node 108 to maintain the voltage at the control node 108 continuously above the activation threshold. In this way, the holding current can be less than the activation current while maintaining the current-controlled switching element 104 in the on state, which can reduce the amount of power used to switch the current-controlled switching element 104 compared to a device that only uses a pre-configured time. In addition, reducing the power loss in switching the current-controlled switching element 104 can help reduce the waste heat generated by the current-controlled switching element 104, which can help increase the reliability of the current-controlled switching element 104 and / or help reduce the amount of heat dissipation required by the system 100.

[0032] Figure 2 is a graph illustrating example behavior of a current-controlled switching element, according to one or more techniques of this disclosure. Figure 2 The horizontal axis (x-axis) represents the gate voltage (V GS (V)), the unit is volts. Figure 2 The vertical axis (y-axis) represents the drain current 202 (I D (A)), in amperes, and the gate current 204 (I G (mA)), the unit is milliampere. Figure 2 The targeted drain to source voltage was 8 volts and the temperature was 25°C.

[0033] Figure 2 The dedicated gate profile transfer function is shown in the figure. Figure 2 One challenge in operating a switching element with a gate profile as shown in the example of FIG. 1 is to quickly switch the current-controlled switching element 104 without damaging the current-controlled switching element 104. Figure 2 As shown in the example of , a gate current 204 of less than 1.25 mA results in a gate voltage of 3.3 volts and a drain current 202 of 45 amps.

[0034] Figure 3 is a conceptual diagram of a control current for driving a current-controlled switching element according to one or more techniques of this disclosure. Figure 3 The horizontal axis (x-axis) represents time. Figure 3 The vertical axis (y-axis) represents the gate current 302 (I G,avg ), in amperes. Hereinafter, for illustrative purposes only, GaN devices will be referred to as current-controlled switching elements.

[0035] exist Figure 3 In the example of FIG. 1 , the driver circuit device 102 may output a high current pulse (I G,pulse ) (referred to herein as the activation current) to enable switching of the GaN-gate structure. In this example, the driver circuit device 102 can output a much lower steady-state current (referred to herein as the holding current) after the GaN-gate structure is turned on. The activation pulse can be configured to be fast on and off (e.g., high current peak). In contrast, the holding current can be configured to be a lower steady-state current after turning on. The holding current can be sufficient to charge the control node 108 to maintain the voltage at the control node 108 continuously above the activation threshold.

[0036] Figure 4is a block diagram illustrating an example system 400 configured to control a current-controlled switching element 404 using a low-current driver circuit 422 and a high-current driver circuit 424, according to one or more techniques of this disclosure. Figure 4 As shown, system 400 includes a switch circuit arrangement 420, a driver circuit arrangement 402, and a current-controlled switch element 404. Driver circuit arrangement 402 may include a low-current driver circuit 422, a high-current driver circuit 424, and a comparator 414.

[0037] The switching circuit device 420 can be configured to generate a switching signal, such as a pulse width modulation (PWM) signal or other type of pulse modulation signal (such as a pulse density modulation signal, a pulse duration modulation signal, a pulse frequency modulation signal, or other types of modulation). The switching signal can indicate when to operate the current-controlled switching element 404 in the on state (e.g., the high portion of the PWM signal) and when to operate the current-controlled switching element 404 in the off state (e.g., the low portion of the PWM signal). The switching signal can indicate additional components, such as a dead time component of the PWM signal.

[0038] The system 400 can include active feedback from a control node 408 of the current-controlled switching element 404 (e.g., the gate of the GaN device) so that the driver circuit device 402 automatically senses a turn-on event and reduces the driver strength. For example, the active feedback can represent feedback from the control node 408. In this example, when the voltage at the control node 408 detected using the output node 406 exceeds a reference voltage, the driver circuit device 402 can detect that a switching event has occurred. For example, the active feedback can represent feedback from the control node 408 to the negative terminal of the comparator 414. In this case, the positive terminal of the comparator 414 can be electrically coupled to the reference voltage (V ref When the voltage at the control node of the current-controlled switching element 404 exceeds the reference voltage, the comparator 414 may output a first value (e.g., logic 0), and when the voltage at the control node of the current-controlled switching element 404 does not exceed the reference voltage, the comparator 414 may output a second value (e.g., logic 1).

[0039] exist Figure 4In the example of FIG4 , while the switching signal indicates that the current-controlled switching element 404 is operated in the on state, the low-current driver circuit 422 can output the holding current to the output node 406. For example, the low-current driver circuit 422 can output the holding current to the output node 406 during a high portion of the PWM signal output by the switching circuit device 420. In this case, the low-current driver circuit 422 can stop outputting the holding current to the output node 406 during a low portion of the PWM signal output by the switching circuit device 420 and / or during a dead-time portion of the PWM signal.

[0040] The high-current driver circuit 424 can output a supplementary current to the output node 406 for only a portion of the time when the switching signal output by the switching circuit device 420 indicates that the current-controlled switching element 404 is operated in the on-state, forming an activation current when the supplementary current is combined with the holding current output by the low-current driver circuit 422. For example, the high-current driver circuit 424 can begin outputting the supplementary current to the output node 406 during a high portion of the PWM signal output by the switching circuit device 420 and end outputting the supplementary current when the comparator 414 detects that a switching event has occurred. The high-current driver circuit 424 can refrain from outputting the supplementary current to the output node 406 while the switching signal indicates that the current-controlled switching element is operated in the off-state (e.g., during a low portion of the PWM signal output by the switching circuit device 420 and / or during a dead-time portion of the PWM signal). In this way, the low current driver circuit 422 can be implemented to provide a relatively high precision current at a relatively low switching rate (e.g., a current source), and the high current driver circuit 424 can be implemented to provide a relatively low precision current at a relatively high switching rate (e.g., a resistor and switch element arranged in series), which can reduce the complexity of the driver circuit device and / or reduce the cost of the driver circuit device compared to a system that uses a single current driver to provide both the activation current and the holding current.

[0041] Figure 5 is a diagram illustrating a method of performing a Figure 4 Graphs of an example voltage at the control node of the current-controlled switching element 404 and a current at the control node 408 . Figure 5 The horizontal axis (x-axis) represents time. Figure 5 The vertical axis (y-axis) represents the gate voltage 502 (V GS (V)), in volts, and the gate-to-source current 504 (I GS (A)), the unit is ampere.

[0042] exist Figure 5In the example shown in FIG. 4 , at time t1, the low current driver circuit 422 outputs a holding current to the control node 408, and the high current driver outputs a supplementary current to the control node 408, resulting in a gate voltage 502 and a gate-to-source current 504. In this example, the driver circuit device 402, or more particularly, for example, the comparator 414, may output a holding current to the control node 408 when the gate voltage 502 exceeds the reference voltage 510 (V ref ) when the switching event has occurred. The high current driver circuit 424 may stop outputting the supplementary current when the driver circuit device 402 detects that the switching event has occurred, thereby obtaining the gate-to-source current 504 dropping to the holding current output by the low current driver circuit 422 at time t2.

[0043] Figure 6 is a block diagram illustrating an example system 600 configured to control a current-controlled switching element 604 using a low-current driver circuit 622, a high-current driver circuit 624, and a timer 630, according to one or more techniques of this disclosure. Figure 6 As shown, system 600 includes a switching circuit device 620, a driver circuit device 602, and a current-controlled switching element 604. Driver circuit device 602 may include a current driver 612, current driver 612 including a low current driver circuit 622 and a high current driver circuit 624, a detection circuit device 614, and a timer circuit device 631. Timer circuit device 631 may include a timer 630 and a tri-state logic 632. Switching circuit device 620 may be configured to generate a switching signal, such as a pulse width modulation (PWM) signal.

[0044] The timer circuit device 631 can start the timer 630 in response to a switching cycle of the switching signal output by the switching circuit device 620, the switching signal indicating that the operating current-controlled switching element 604 changes from the off state to the on state. In this example, the timer circuit device 631, or more specifically, for example, the tri-state logic 632, can output a signal based on the timer. For example, the timer circuit device 631, or more specifically, for example, the tri-state logic 632, can determine whether the detection circuit device 614 detects a switching event after the timer 630 is started, and can output a signal when the timer exceeds a threshold time value and the detection circuit device 614 has not detected a switching event.

[0045] In response to a switching cycle of a switching signal output by the switching circuit arrangement 620 indicating that the operating current-controlled switching element 604 is to change from an off state to an on state, the current driver circuit 612 can output an activation current to the control node 608. For example, the low-current driver circuit 622 can output a holding current to the output node 606, and the high-current driver circuit 624 can output a supplementary current to the output node 606. When the timer circuit arrangement 631 outputs a signal, the current driver circuit 612 can output the holding current to the output node 606. For example, the low-current driver circuit 622 can output the holding current to the output node 606, and the high-current driver circuit 624 can stop outputting the supplementary current to the output node 606. In this way, the driver circuit arrangement 602 can help ensure that the activation current is supplied to the current-controlled switching element for no more than a threshold amount of time, which can reduce or eliminate the risk of the activation current damaging the current-controlled switching element 604.

[0046] Figure 7 is a diagram illustrating a method of performing a Figure 6 Graphs of an example voltage at a control node of a current-controlled switching element 604 and a current at the control node. Figure 7 The horizontal axis (x-axis) represents time. Figure 7 The vertical axis (y-axis) represents the gate voltage 702 (V GS (V)), the unit is volts, the first gate-to-source current 704 (I GS (A)), in amperes, and the second gate-to-source current 706 (I GS (A)), the unit is ampere.

[0047] exist Figure 7 In the example shown in FIG. 1 , at time t1, the low current driver circuit 622 will output a holding current to the control node 608, and the high current driver will output a supplementary current to the control node 608, thereby obtaining a gate voltage 702 and a gate-to-source current 704. In this example, the driver circuit device 602, or more specifically, the detection circuit device 614, can be configured to detect the gate voltage 702 when the gate voltage 702 exceeds the reference voltage 710 (V ref ) when the switching event has occurred. The high current driver circuit 624 may stop outputting the supplemental current when the driver circuit arrangement 602 detects that the switching event has occurred, which results in the gate-to-source current 704 dropping to the holding current output by the low current driver circuit 622 at time t2. Time t2 may be determined by a feedback loop from the control node 608 and / or the detection circuit arrangement 614.

[0048] In one example, when driver circuitry 602 does not detect the occurrence of a switching event, timer circuitry 631 can help ensure that the activation current does not damage the controlled switching element 604. For example, timer circuitry 631, or more specifically, tri-state logic 632, can determine whether detection circuitry 614 has detected a switching event after timer 630 is initiated, and can output a signal when timer 630 exceeds a threshold time value and detection circuitry 614 has not detected a switching event. When timer circuitry 631 outputs the signal, current driver circuitry 612 can output a holding current to output node 606. For example, low-current driver circuitry 622 can output the holding current to output node 606, and high-current driver circuitry 624 can stop outputting the supplemental current to output node 606. In this way, driver circuitry 602 can help ensure that the activation current is supplied to the current-controlled switching element for no more than a threshold amount of time t3, which can reduce or eliminate the risk of the activation current damaging the current-controlled switching element 604. Time t3 can represent a safe time that helps ensure that driver circuitry 602 does not damage the current-controlled switching element 604.

[0049] Figure 8 is a block diagram illustrating an example system 800 configured to control a current-controlled switching element 804 using a low-current driver circuit 822 , a high-current driver circuit 824 , a timer 830 , and safety logic 840 , according to one or more techniques of this disclosure.

[0050] like Figure 8 As shown in FIG, system 800 includes a switching circuit device 820, a driver circuit device 802, and a current-controlled switching element 804. Driver circuit device 802 may include a current driver 812, current driver 812 includes a low current driver circuit 822 and a high current driver circuit 824, a detection circuit device 814, and a timer circuit device 831. Timer circuit device 831 may include a timer 830 and a tri-state logic 832. Switching circuit device 820 may be configured to generate a switching signal, such as a PWM signal.

[0051] exist Figure 8In the example of FIG. 8 , timer circuitry 831 can initiate timer 830 in response to a switching cycle of a switching signal output by switching circuitry 820 indicating that current-controlled switching element 804 is switched from an OFF state to an ON state. In this example, timer circuitry 831, or more specifically, tri-state logic 832, can output a signal based on the timer. For example, timer circuitry 831, or more specifically, tri-state logic 832, can determine whether detection circuitry 814 has detected a switching event after timer 830 is initiated, and can output a signal when the timer exceeds a threshold time value and detection circuitry 814 has not detected a switching event. When timer circuitry 831 outputs a signal, safety logic 840 can output a safety signal.

[0052] Figure 9 is a block diagram illustrating an example system 900 configured to control a current-controlled switching element 904 using a low-current driver circuit 922, a high-current driver circuit 924, a timer 930, safety logic 940, and a voltage monitor 942, according to one or more techniques of this disclosure.

[0053] like Figure 9 As shown in FIG, system 900 includes a switching circuit device 920, a driver circuit device 902, and a current-controlled switching element 904. Driver circuit device 902 may include a current driver circuit 912, wherein current driver circuit 912 includes a low current driver circuit 922 and a high current driver circuit 924, a detection circuit device 914, and a timer circuit device 931. Timer circuit device 931 may include a timer 930 and a tri-state logic 932. Switching circuit device 920 may be configured to generate a switching signal, such as a PWM signal.

[0054] exist Figure 9 In the example of FIG. 1 , timer circuit device 931 can start timer 930 in response to a switching cycle of a switching signal output by switching circuit device 920 indicating that current-controlled switching element 904 changes from an off state to an on state. In this example, timer circuit device 931, or more specifically, tri-state logic 932, can output a signal based on the timer. For example, timer circuit device 931, or more specifically, tri-state logic 932, can determine whether detection circuit device 914 has detected a switching event after timer 930 is started, and can output a signal when the timer exceeds a threshold time value and detection circuit device 914 has not detected a switching event.

[0055] and Figure 8Similarly, when timer circuitry 931 outputs a signal, safety logic 940 may output a safety signal. For example, safety logic may store a count multiple times within a time period. Furthermore, driver circuitry 902 may include a voltage monitor 942. Voltage monitor 942 may output an indication of the voltage at control node 908 to safety logic 940. For example, voltage monitor 942 may output a digital value representing the voltage at control node 908 to safety logic 940. In this example, safety logic 940 may output an indication of the voltage at control node 908 in the safety signal. For example, while current driver circuitry 912 operates current-controlled switching element 904 in a conductive state, voltage monitor 942 may generate an indication that the voltage at control node 908 is at a peak value of the voltage at control node 908. For example, voltage monitor 942 may generate a digital value indicating the peak voltage during a portion of a switching cycle at control node 908.

[0056] Figure 10 is a block diagram illustrating an example system 1000 configured to control a current-controlled switching element 1004 using a low-current driver circuit 1022, a high-current driver circuit 1024, a timer 1030, safety logic 1040, and an event counter 1044, according to one or more techniques of this disclosure.

[0057] like Figure 10 As shown, system 1000 includes a switching circuit device 1020, a driver circuit device 1002, and a current-controlled switching element 1004. Driver circuit device 1002 may include a current driver 1012, wherein current driver 1012 includes a low current driver circuit 1022 and a high current driver circuit 1024, a detection circuit device 1014, and a timer circuit device 1031. Timer circuit device 1031 may include a timer 1030 and a tri-state logic 1032. Switching circuit device 1020 may be configured to generate a switching signal, such as a PWM signal.

[0058] exist Figure 10 In the example of FIG. 1 , timer circuit device 1031 can start timer 1030 in response to a switching cycle of a switching signal output by switching circuit device 1020 indicating that current-controlled switching element 1004 has changed from an off state to an on state. In this example, timer circuit device 1031, or more specifically, tri-state logic device 1032, can output a signal based on the timer. For example, timer circuit device 1031, or more specifically, tri-state logic device 1032, can determine whether detection circuit device 1014 has detected a switching event after timer 1030 is started, and can output a signal when the timer exceeds a threshold time value and detection circuit device 1014 has not detected a switching event.

[0059] The safety logic 1040 can output a safety signal when the timer circuit device 1031 outputs a signal. The event counter 1044 can store a count multiple times within a time period. The time period can start from the start of the driver circuit device 1002, from a periodic time window (e.g., every hour or every day), and / or from a controller requesting that the event counter 1044 store a count. The time counter 1044 can output the count to the microcontroller.

[0060] Figure 11 1 is a block diagram illustrating an example system 1100 for controlling a current-controlled switching element 1104 using a low-current driver circuit 1122 having a first and second resistive components 1164 and a high-current driver circuit 1124 having a second resistive component 1174, according to one or more techniques of this disclosure. Figure 11 As shown in FIG, system 1100 includes a switch circuit device 1120, a driver circuit device 1102, and a current-controlled switch element 1104. Driver circuit device 1102 may include driver circuit device 1112 and a comparator 1114. Driver circuit device 1112 includes a low current driver circuit 1122 and a high current driver circuit 1124.

[0061] exist Figure 11 In the example of FIG. 1 , low current driver circuit 1122 includes a first switching element 1162 configured to electrically couple a first resistive component 1164 to a power supply voltage 1160. High current driver circuit 1124 includes a second switching element 1172 configured to electrically couple a second resistive component 1174 to a power supply voltage 1170, where power supply voltage 1170 can be the same power supply voltage as power supply voltage 1160. In some examples, first resistive component 1164 includes a higher precision resistor than second resistive component 1174. For example, first resistive component 1164 can have a smaller resistance band around a target resistance than second resistive component 1174.

[0062] The high current driver circuit 1124 may include logic circuitry that drives the second switching element 1172 based on a switching signal output by the switching circuitry 1120 and an output from the comparator 1114. For example, the high current driver circuit 1124 may include an AND gate having a first input connected to the output of the switching circuitry 1120, a second input connected to the output of the comparator 1114, and an output connected to a control node (e.g., a gate) of the second switching element 1172. In this example, in response to a switching signal instructing the current-controlled switching element to change from an OFF state to an ON state, and while the comparator 1114 detects that the voltage at the control node of the current-controlled switching element 1104 does not exceed a reference voltage, the high current driver circuit 1124 may begin operating the second switching element 1172 in the ON state. In this example, the high current driver circuit 1124 may subsequently operate the second switching element 1172 in the OFF state in response to the comparator 1114 detecting that the voltage at the control node of the current-controlled switching element 1104 exceeds the reference voltage.

[0063] Figure 12 1 is a block diagram illustrating an example system 1200 configured to control a current-controlled switching element 1204 using a low-current driver circuit 1222 having a current source 1280, according to one or more techniques of this disclosure. Figure 12 As shown in FIG, system 1200 includes a switch circuit device 1220, a driver circuit device 1202, and a current-controlled switch element 1204. Driver circuit device 1202 may include driver circuit device 1212 and a comparator 1214. Driver circuit device 1212 includes a low current driver circuit 1222 and a high current driver circuit 1224.

[0064] exist Figure 12 In the example of FIG. 1 , the low current driver circuit 1222 includes a current source 1280 . The current source 1280 can be configured to generate a holding current. The high current driver circuit 1224 includes a second switching element 1272 configured to electrically couple the second resistive component 1274 to the supply voltage 1270 .

[0065] Figure 13 is a flow chart for controlling the current-controlled switching element 104 according to one or more techniques of this disclosure. Figure 13 For illustrative purposes only Figures 1-12 discuss.

[0066] The driver circuit device 102, or more specifically, the current driver circuit 112, can determine a switching signal that indicates that the current-controlled switching element 104 should be operated from an off state to an on state. The current-controlled switching element 104 can be configured to change from operating in the off state to operating in the on state when a charge supplied to a control node of the current-controlled switching element causes the voltage at the control node to be greater than an activation threshold. For example, the current-controlled switching element 104 can include a gallium nitride (GaN) switching element. In some examples, the current-controlled switching element 104 includes a gate injection transistor (GIT) switching element.

[0067] In response to a switch signal indicating that the operating current-controlled switching element changes from an off state to an on state, the current driver circuit 112 may output an activation current to an output node configured to be electrically coupled to a control node. The activation current may be configured to supply charge to the control node, thereby causing the voltage at the control node to be greater than an activation threshold. For example, while the switch signal indicates that the current-controlled switching element 404 is operated in the on state, the low current driver circuit 422 may output a holding current to the output node 406, and during only a portion of the time when the switch signal indicates that the current-controlled switching element is operated in the on state, the high current driver circuit 424 may output a supplementary current to the output node 406, forming an activation current when the supplementary current is combined with the holding current output by the low current driver circuit 422. The low current driver circuit 422 may include a resistive element and a switching element (see Figure 11 In some examples, the low current driver circuit 422 may include a current source (see Figure 12 ). The high current driver circuit 424 may include a resistor element and a switch element (see Figure 11 、 Figure 12 ).

[0068] Detection circuitry 114 may detect when a switching event has occurred based on the voltage at control node 108 while outputting the activation current. For example, detection circuitry 114 may detect that a switching event has occurred when the voltage at control node 108 exceeds a reference voltage.

[0069] When detecting that a switching event has occurred, the current driver circuit 112 may output a holding current to the output node 106. For example, in response to detecting that a switching event has occurred, the current driver circuit 112 may output a holding current to the output node 106. The holding current may be sufficient to charge the control node 108, thereby maintaining the voltage at the control node 108 continuously above the activation threshold.

[0070] In some examples, the driver circuit device 102 may include a timer circuit device. For example, in response to a switching cycle of a switching signal output by the switching circuit device 620 indicating that the operating current-controlled switching element 604 changes from an off state to an on state, the timer circuit device 631 may start the timer 630. In this example, the timer circuit device 631, or more specifically, the tri-state logic 632, may output a signal based on the timer. For example, the timer circuit device 631, or more specifically, the tri-state logic 632, may determine whether the detection circuit device 614 has detected a switching event after starting the timer 630, and may output a signal when the timer exceeds a threshold time value and the detection circuit device 614 does not detect a switching time. When the timer circuit device 631 outputs a signal, the current driver circuit 612 may output a holding current to the output node 606. In some examples, the driver circuit device 102 may include one or more safety logics configured to output a safety signal when the timer circuit device outputs a signal (see Figure 8 ), a voltage monitor configured to output an indication of the voltage at the control node to the safety logic (see Figure 9 ), or event counter (see Figure 10 ).

[0071] The following clauses may illustrate one or more aspects of the present disclosure.

[0072] Item 1. A device for controlling a current-controlled switching element, the device comprising: an output node configured to be electrically coupled to a control node of the current-controlled switching element, the current-controlled switching element being configured to change from operating in an off state to operating in an on state when a charge supplied to the control node causes a voltage at the control node to be greater than an activation threshold; a current driver circuit configured to output an activation current to the output node in response to a switching signal indicating that the current-controlled switching element is operating from an off state to an on state, the activation current being configured to supply charge to the control node, thereby causing the voltage at the control node to be greater than the activation threshold; a detection circuit device configured to detect when a switching event has occurred based on the voltage at the control node while the current driver circuit is outputting the activation current; and wherein the current driver circuit is further configured to output a holding current to the output node when the detection circuit device detects that a switching event has occurred.

[0073] Clause 2. The apparatus of clause 1, wherein the holding current is sufficient to charge the control node to maintain a voltage at the control node continuously above the activation threshold.

[0074] Clause 3. The apparatus of clauses 1-2, wherein the detection circuitry is configured to detect that a switching event has occurred when a voltage at the control node exceeds a reference voltage.

[0075] Clause 4. The device described in Clauses 1 to 3 further includes a timer circuit device, which is configured to: start a timer in response to a switching cycle of a switching signal, wherein the switching signal indicates that the operating current-controlled switching element changes from an off state to an on state; and wherein the current driver circuit is further configured to output a holding current when the timer circuit device outputs a signal.

[0076] Item 5. The apparatus of Item 4, wherein the timer circuit device is further configured to: determine whether the detection circuit device has detected a switching event after starting the timer; and output a signal when the timer exceeds a threshold time value and the detection circuit device has not detected a switching event.

[0077] Clause 6. The apparatus of clauses 4-5, further comprising safety logic configured to output a safety signal when the timer circuitry outputs a signal.

[0078] Clause 7. The apparatus of clause 6, further comprising: a voltage monitor configured to output an indication of the voltage at the control node to the safety logic; and wherein to output the safety signal, the safety logic is further configured to output an indication of the voltage at the control node.

[0079] Clause 8. The apparatus of Clause 7, wherein the voltage monitor is configured to generate an indication that the voltage at the control node is a peak value of the voltage at the control node while the current driver circuit operates the current-controlled switching element in a conductive state.

[0080] Clause 9. The device described in Clauses 1 to 8, wherein the current driver circuit includes: a low current driver circuit configured to output a holding current to an output node while a switching signal indicates that the current-controlled switching element is operating in an on-state; and a high current driver circuit configured to output a supplementary current to the output node only for a portion of the time when the switching signal indicates that the current-controlled switching element is operating in an on-state, wherein the supplementary current forms an activation current when combined with the holding current output by the low current driver circuit.

[0081] Item 10. The device of Item 9, wherein the low current driver circuit is further configured to stop outputting the holding current while the switching signal indicates to operate the current-controlled switching element in an off state.

[0082] Clause 11. The apparatus of clauses 9-10, wherein the low current driver circuit comprises a first switching element configured to electrically couple the first resistive component to a power supply voltage; and wherein the high current driver circuit comprises a second switching element configured to electrically couple the second resistive component to the power supply voltage.

[0083] Clause 12. The apparatus of clause 11, wherein the first resistive component comprises resistors of higher precision than the second resistive component.

[0084] Clause 13. The apparatus of clauses 9-10, wherein the low current driver circuit comprises a current source configured to generate a holding current.

[0085] Clause 14. The apparatus of clauses 1-13, wherein the current-controlled switching element comprises a gallium nitride (GaN) switching element.

[0086] Clause 15. The apparatus of clauses 1-14, wherein the current-controlled switching element comprises a gate injection transistor (GIT) switching element.

[0087] Item 16. A method comprising: determining that a switch signal indicates that an operating current-controlled switching element changes from an off state to an on state, the current-controlled switching element being configured to change from operating in an off state to operating in an on state when a charge supplied to a control node of the current-controlled switching element causes a voltage at the control node to be greater than an activation threshold; in response to the switch signal indicating that the operating current-controlled switching element changes from an off state to an on state, outputting an activation current to an output node configured to be electrically coupled to the control node, the activation current being configured to supply charge to the control node, thereby causing the voltage at the control node to be greater than the activation threshold; detecting when a switching event has occurred based on the voltage at the control node while outputting the activation current; and outputting a holding current to the output node when it is detected that the switching event has occurred.

[0088] Item 17. A system comprising: a current-controlled switching element configured to change from operating in an off state to operating in an on state when a charge supplied to a control node of the current-controlled switching element causes a voltage at the control node to be greater than an activation threshold; and a driver circuit device comprising: an output node configured to be electrically coupled to the control node of the current-controlled switching element; a current driver circuit configured to output an activation current to the output node in response to a switching signal indicating that the current-controlled switching element is operated to change from an off state to an on state, the activation current being configured to supply charge to the control node, thereby causing the voltage at the control node to be greater than the activation threshold; a detection circuit device configured to detect when a switching event has occurred based on the voltage at the control node while the current driver circuit outputs the activation current; and wherein the current driver circuit is further configured to output a holding current to the output node when the detection circuit device detects that the switching event has occurred.

[0089] Clause 18. The system of clause 17, wherein the holding current is sufficient to charge the control node to maintain a voltage at the control node continuously above the activation threshold.

[0090] Clause 19. The system of clauses 17-18, wherein the current-controlled switching element comprises a gallium nitride (GaN) switching element.

[0091] Clause 20. The system of clauses 17-19, wherein the current-controlled switching element comprises a gate injection transistor (GIT) switching element.

[0092] The technology of the present disclosure can be implemented in various devices or apparatuses, including wireless handsets, integrated circuits (ICs), or integrated circuit sets (e.g., chipsets). Various components, modules, and units are described in this disclosure to emphasize the functional aspects of devices configured to implement the technology of the present disclosure, but are not required to be implemented by different hardware units. Instead, as described above, different units can be combined in a hardware unit or provided by a set of interoperable hardware units, including one or more processors as described above, in combination with appropriate software and / or firmware.

[0093] Various aspects have been described in this disclosure. These and other aspects are within the scope of the following claims.

Claims

1. A device for controlling a current-controlled switching element, the device comprising: an output node configured to be electrically coupled to a control node of the current-controlled switching element, the current-controlled switching element being configured to change from operating in an off state to operating in an on state when a charge supplied to the control node causes a voltage at the control node to be greater than an activation threshold; a current driver circuit configured to output an activation current to the output node in response to a switch signal, the switch signal indicating operation of the current-controlled switch element to change from the off state to the on state, the activation current configured to supply the charge to the control node to cause the voltage at the control node to be greater than the activation threshold; a detection circuit arrangement configured to detect when a switching event has occurred based on the voltage at the control node while the current driver circuit is outputting the activation current; and Wherein the current driver circuit is further configured to output a holding current to the output node when the detection circuit device has detected that the switching event has occurred. 2 . The apparatus of claim 1 , wherein the holding current is sufficient to charge the control node to maintain the voltage at the control node continuously above the activation threshold. 3 . The apparatus of claim 1 , wherein the detection circuitry is configured to detect that the switching event has occurred when the voltage at the control node exceeds a reference voltage.

4. The apparatus of claim 1 , further comprising a timer circuit device configured to: starting a timer in response to a switching cycle of the switching signal, the switching signal indicating operation of the current-controlled switching element to change from the off state to the on state; outputting a signal based on the timer; and The current driver circuit is further configured to output the holding current when the timer circuit device outputs the signal.

5. The apparatus of claim 4, wherein the timer circuit arrangement is further configured to: After starting the timer, determining whether the detection circuit arrangement has detected the switching event; and The signal is output when the timer exceeds a threshold time value and the detection circuit device does not detect the switching event. 6 . The apparatus of claim 4 , further comprising safety logic configured to output a safety signal when the timer circuit device outputs the signal.

7. The device according to claim 6, further comprising: a voltage monitor configured to output an indication of the voltage at the control node to the safety logic; as well as Wherein to output the safety signal, the safety logic is further configured to output the indication of the voltage at the control node.

8. The apparatus of claim 7, wherein the voltage monitor is configured to generate the indication that the voltage at the control node is a peak value of the voltage at the control node while the current driver circuit operates the current controlled switching element in the on state.

9. The apparatus of claim 1 , wherein the current driver circuit comprises: a low current driver circuit configured to: output the holding current to the output node while the switch signal indicates to operate the current-controlled switch element in the on-state; as well as A high current driver circuit is configured to output a supplementary current to the output node only for a portion of the time when the switch signal indicates that the current-controlled switching element is operated in the on state, and the supplementary current forms the activation current when combined with the holding current output by the low current driver circuit. 10 . The device of claim 9 , wherein the low current driver circuit is further configured to stop outputting the holding current while the switch signal indicates operating the current control type switching element in the off state.

11. The device according to claim 9, wherein the low current driver circuit comprises a first switching element configured to electrically couple a first resistive component to a supply voltage; and Wherein the high current driver circuit includes a second switching element configured to electrically couple a second resistive component to the supply voltage.

12. The apparatus of claim 11, wherein the first resistance component comprises higher precision resistance than the second resistance component. 13 . The apparatus of claim 9 , wherein the low current driver circuit comprises a current source configured to generate the holding current.

14. The apparatus of claim 1, wherein the current-controlled switching element comprises a gallium nitride (GaN) switching element.

15. The apparatus of claim 1, wherein the current-controlled switching element comprises a gate injection transistor (GIT) switching element.

16. A method comprising: determining a switch signal indicating that an operation current-controlled switching element changes from an off state to an on state, the current-controlled switching element being configured to change from operating in the off state to operating in the on state when a charge supplied to a control node of the current-controlled switching element causes a voltage at the control node to be greater than an activation threshold; In response to the switch signal indicating operation of the current-controlled switch element to change from the off state to the on state, outputting an activation current to an output node, the output node being configured to be electrically coupled to the control node, the activation current being configured to supply the charge to the control node to cause the voltage at the control node to be greater than the activation threshold; while outputting the activation current, detecting when a switching event has occurred based on the voltage at the control node; as well as When it is detected that the switching event has occurred, a holding current is output to the output node.

17. A system comprising: a current-controlled switching element configured to change from operating in an off state to operating in an on state when a charge supplied to a control node of the current-controlled switching element causes a voltage at the control node to be greater than an activation threshold; as well as A driver circuit device comprising: an output node configured to be electrically coupled to the control node of the current-controlled switching element; a current driver circuit configured to output an activation current to the output node in response to a switch signal, the switch signal indicating operation of the current-controlled switch element to change from the off state to the on state, the activation current configured to supply the charge to the control node to cause the voltage at the control node to be greater than the activation threshold; a detection circuit arrangement configured to detect when a switching event has occurred based on the voltage at the control node while the current driver circuit is outputting the activation current; and Wherein the current driver circuit is further configured to output a holding current to the output node when the detection circuit device has detected that the switching event has occurred.

18. The system of claim 17, wherein the holding current is sufficient to charge the control node to maintain the voltage at the control node continuously above the activation threshold.

19. The system of claim 17, wherein the current-controlled switching element comprises a gallium nitride (GaN) switching element.

20. The system of claim 17, wherein the current controlled switching element comprises a gate injection transistor (GIT) switching element.

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