Driving circuit, driving chip and converter
By designing the Miller clamping unit of the driving circuit in the converter, the controlled switch tube is clamped Miller clamped, which solves the problem of misdirection of the switch tube in the lower bridge arm in the converter, ensuring the normal operation of the equipment and reducing costs.
Patent Information
- Application Number
- CN202421879472.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-05
- Publication Date
- 2025-06-24
- Estimated Expiration
- 2034-08-05
AI Technical Summary
In the converter, the lower bridge arm switch tube may generate Miller capacitance current when switching the upper bridge arm switch tube state, resulting in misdirection, affecting the normal operation of the equipment and possibly causing damage.
A driving circuit is designed, including a driving unit, a shutdown unit, a control unit and a Miller clamping unit. The controlled switch tube is clamped through the Miller clamping unit to ensure that its control end circuit is in a low resistance state and avoid misdirection.
It effectively avoids misdirection of the controlled switch tube, ensures the normal operation of the equipment, and reduces the cost of the driving circuit, which is conducive to miniaturization design.
Smart Images
Figure CN223024295U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of power electronics technology, and particularly relates to a drive circuit, a drive chip, and an inverter. Background Art
[0002] In the power supply field, an inverter is generally provided to realize the conversion between the power supply voltage and the load supply voltage. Generally, multiple bridge arms are provided in the inverter, and each bridge arm is composed of two series-connected switching tubes. When the state of the upper-bridge-arm switching tube changes from off to on, a Miller capacitance current will be generated in the lower-bridge-arm switching tube. When this current passes through the gate circuit of the lower-bridge-arm switching tube, a voltage drop greater than the threshold voltage of the lower-bridge-arm switching tube may be generated, resulting in mis-conduction of the lower-bridge-arm switching tube, thereby affecting the normal operation of the device, and in severe cases, even causing damage to the device. Summary of the Utility Model
[0003] The present application provides a drive circuit, a drive chip, and an inverter for performing Miller clamping on a controlled switching tube to avoid mis-conduction of the controlled switching tube and ensure the normal operation of the device to which the controlled switching tube belongs.
[0004] In a first aspect, an embodiment of the present application provides a drive circuit, which can be applied to an inverter and control the conduction and turn-off of the lower-bridge-arm switching tube in the inverter. Wherein, the drive circuit may include a drive unit, a turn-off unit, a control unit, and a Miller clamping unit.
[0005] Specifically, the drive unit is connected to the control unit, and is used to be connected to the control end of the controlled switching tube and charge the control end of the controlled switching tube when receiving the first signal; the turn-off unit is connected to the control unit, and is used to be connected to the control end of the controlled switching tube and discharge the control end of the controlled switching tube when receiving the second signal; the Miller clamping unit includes a first switch and a resistor branch. The first end of the first switch is connected to the first end of the discharge resistor in the turn-off unit, the second end of the first switch is connected to the second end of the discharge resistor, the control end of the first switch is connected to the middle node of the resistor branch, and the resistor branch is connected between the first end of the discharge resistor and the control unit.
[0006] With the above design, after the control unit sends a second signal for controlling the controlled switch transistor to the turn-off unit, the turn-off unit operates and constructs a discharge path for the control terminal of the controlled switch transistor. When the discharge current passes through the discharge resistor, a voltage difference is formed between the discharge resistor and the control chip. This voltage difference causes the resistor branch to form an electric energy transmission path and provides the bias voltage required for charging the control terminal of the first switch. When the control terminal of the first switch is charged to the threshold voltage, the first switch conducts and shorts the discharge resistor, thereby providing a low-impedance loop for the control terminal of the controlled switch transistor. Therefore, even if the Miller capacitance current appears, the voltage generated by this current on the low-impedance loop cannot reach the threshold voltage required for the controlled switch to conduct, thus avoiding the occurrence of mis-conduction and ensuring the normal operation of the circuit. In addition, since the Miller clamping unit only includes resistor devices and switch devices, the cost of driving the controlled switch transistor is reduced, and it is beneficial to the miniaturized design of the drive circuit.
[0007] In a possible design, the resistor branch includes a plurality of resistors connected in series.
[0008] In a possible design, the resistor branch includes a first resistor and a second resistor.
[0009] Wherein, the first end of the first resistor is connected to the first end of the discharge resistor, and the second end of the first resistor is connected to the first end of the second resistor; the first end of the second resistor is connected to the control terminal of the first switch, and the second end of the second resistor is connected to the control unit.
[0010] In a possible design, the turn-off unit includes a third resistor, a fourth resistor, a first diode, a second switch, a fifth resistor, and the discharge resistor.
[0011] Wherein, the first end of the third resistor is connected to the control unit, and the second end of the third resistor is connected to the second end of the fourth resistor; the first end of the fourth resistor is connected to the anode of the first diode, and the second end of the fourth resistor is connected to the control terminal of the second switch; the cathode of the first diode is connected to the control unit; the first end of the second switch is connected to the first end of the discharge resistor; the second end of the second switch is used to be connected to a first power supply, and the control terminal of the second switch is connected to the first end of the fifth resistor; the second end of the fifth resistor is connected to the second end of the second switch; the first end of the discharge resistor is connected to the first end of the first switch and the first end of the first resistor, and the second end of the discharge resistor is used to be connected to the control terminal of the controlled switch transistor.
[0012] In a possible design, the drive unit includes a sixth resistor, a seventh resistor, a second diode, a third switch, an eighth resistor, and a drive resistor.
[0013] Among them, the first end of the sixth resistor is connected to the control unit, and the second end of the sixth resistor is connected to the second end of the seventh resistor; the first end of the seventh resistor is connected to the cathode of the second diode, and the second end of the seventh resistor is connected to the control end of the third switch; the anode of the second diode is connected to the control unit; the first end of the third switch is used to be connected to a second power supply, and the second end of the third switch is connected to the first end of the driving resistor; the control end of the third switch is connected to the first end of the eighth resistor; the second end of the eighth resistor is connected to the first end of the second switch; the second end of the driving resistor is used to be connected to the control end of the controlled switch tube.
[0014] In a possible design, the first duration for which the first resistor and the second resistor charge the control end of the first switch is greater than or equal to the second duration for which the control end of the controlled switch tube discharges. The first duration is the charging duration required for the first switch to conduct, and the second duration is the duration required for the control end of the controlled switch tube to finish discharging. With the above design, after the turn-off unit discharges the control end of the controlled switch tube, the Miller clamping unit can be controlled to perform Miller clamping on the controlled switch tube, thereby avoiding the Miller clamping unit from affecting the normal turn-off of the controlled switch tube.
[0015] In a possible design, the controlled switch tube is an IGBT, and the switch in the driving circuit is a MOS tube.
[0016] In a second aspect, an embodiment of the present application provides a driving chip, which includes a plurality of external pins and the control unit provided in the first aspect of the present application and any of its possible designs. Among them, the driving unit, the turn-off unit, and the Miller clamping unit are connected to the control unit through the external pins.
[0017] In a third aspect, an embodiment of the present application provides a driving chip, which includes a plurality of external pins and the driving circuit provided in the first aspect of the present application and any of its possible designs. Among them, the controlled switch tube is connected to the driving circuit through the plurality of external pins.
[0018] In a fourth aspect, an embodiment of the present application provides an inverter, which includes a plurality of bridge arms and a plurality of driving circuits provided in the first aspect of the present application and any of its possible designs. Among them, each driving circuit is used to control the conduction and turn-off of the lower bridge arm switch tube in one bridge arm.
[0019] In addition, the technical effects brought by the second to fourth aspects and any of their possible designs can refer to the technical effects brought by different designs in the first aspect of the embodiments of the present application, which will not be elaborated here. Description of the Drawings
[0020] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0021] Figure 1 It is a schematic structural diagram of a driving circuit provided by an embodiment of the present application;
[0022] Figure 2 It is a schematic structural diagram of a Miller clamping unit provided by an embodiment of the present application;
[0023] Figure 3 It is a schematic structural diagram of a turn-off unit provided by an embodiment of the present application;
[0024] Figure 4 It is a schematic structural diagram of a driving unit provided by an embodiment of the present application;
[0025] Figure 5 It is a schematic connection diagram of a driving chip provided by an embodiment of the present application. Specific embodiments
[0026] The following will introduce the application scenarios of the technical solutions in the embodiments of the present application in combination with the drawings in the embodiments of the present application. The solutions provided by the embodiments of the present application can be applied to a power supply system, and the power supply system is configured with a converter for realizing the conversion of the supply voltage and the load supply voltage. Among them, the above power supply system can be, but is not limited to: Uninterruptible Power Supply (UPS), on-board charger for electric vehicles, motor controller for electric vehicles, and new energy power generation system.
[0027] In practical applications, a converter generally includes at least two bridge arms, and two switching tubes are connected in series on each bridge arm, namely the upper bridge arm switching tube and the lower bridge arm switching tube. The above two switching tubes can be selected as metal oxide semiconductor field effect transistors (MOSFETs), and the two switching tubes conduct complementarily. When the upper bridge arm switching tube switches from the off state to the on state, a Miller capacitance current may be generated on the main circuit of the bridge arm. This Miller capacitance current can flow through the parasitic capacitance of the lower bridge arm switching tube to the control end of the lower bridge arm switching tube, and a voltage drop greater than the threshold voltage for the lower bridge arm switching tube to conduct may be generated when passing through the discharge circuit of the lower bridge arm switching tube, thereby causing the lower bridge arm switching tube to be mis-conducted.
[0028] Based on this, the embodiments of the present application provide a drive circuit, a drive chip, and an inverter, which are used to perform Miller clamping on the control terminal of a controlled switching device to avoid mis-conduction of the controlled switching device.
[0029] See Figure 1 As shown, it is a schematic structural diagram of a drive circuit provided by an embodiment of the present application. The drive circuit can be connected to the controlled switching device and is used to control the conduction and turn-off of the controlled switching device. Among them, the controlled switching device is the lower-arm switching device of the bridge arm. As Figure 1 shown, the drive circuit may include a drive unit, a turn-off unit, a control unit, and a Miller clamping unit.
[0030] Among them, the drive unit is connected to the control unit, and is used to be connected to the control terminal of the controlled switching device and charge the control terminal of the controlled switching device when receiving a first signal; the turn-off unit is connected to the control unit, and is used to be connected to the control terminal of the controlled switching device and discharge the control terminal of the controlled switching device when receiving a second signal; the Miller clamping unit includes a first switch and a resistor branch. The first end of the first switch is connected to the first end of the discharge resistor in the turn-off unit, the second end of the first switch is connected to the second end of the discharge resistor, the control end of the first switch is connected to the intermediate node of the resistor branch, and the resistor branch is connected between the first end of the discharge resistor and the control unit.
[0031] In practical applications, each unit in the drive circuit can be an independent device. For example, the control unit is packaged in the drive chip, and the drive unit, the turn-off unit, and the Miller clamping unit can be used as the peripheral circuit of the drive chip and are connected to the control unit through the external pins of the drive chip. Each unit in the drive circuit can also be packaged as an integrated device. For example, the drive unit, the control unit, the turn-off unit, and the Miller clamping unit can all be packaged in the drive chip, and the controlled switching device can be connected to each unit in the drive circuit through the external pins of the drive chip.
[0032] Adopt Figure 1For the driving circuit shown, the control unit can control the on and off of the controlled switching transistor by outputting corresponding signals. For example, when it is necessary to control the controlled switching transistor to turn on, the control unit outputs a first signal, the driving unit operates and charges the control terminal of the controlled switching transistor. When the control terminal of the controlled switching transistor is charged to the voltage required for conduction, the controlled switching transistor turns on. When it is necessary to control the controlled switching transistor to turn off, the control unit outputs a second signal, the turning-off unit operates and discharges the control terminal of the controlled switching transistor. When the control terminal of the controlled switching transistor is discharged completely, the controlled switching transistor turns off. In the turning-off unit, a first switch and a resistor branch for controlling the conduction of the first switch are arranged at both ends of the discharge resistor. When the turning-off unit discharges the controlled switching transistor, a voltage difference is formed between the control unit and the discharge resistor connected to both ends of the resistor branch, a current flows through the resistor branch, and charges the control terminal of the first switch. When the control terminal of the first switch is charged to the voltage required for conduction, the first switch turns on and shorts the discharge resistor in the turning-off unit. At this time, the large-resistance discharge resistor on the discharge path of the controlled switching transistor is shorted, and the discharge path is in a low-resistance state. Therefore, even if the state of the upper-bridge-arm switching transistor changes to generate a Miller capacitance current, this current cannot generate the voltage required for the conduction of the controlled switching transistor through the discharge path, avoiding the situation of mis-conduction of the controlled switching transistor and ensuring the normal operation of the equipment to which the controlled switching transistor belongs. In addition, in the Miller clamping unit for solving the mis-conduction of the controlled switching transistor, there are only switching devices and resistor devices, which reduces the driving cost of the driving circuit and is also conducive to the miniaturized design of the driving circuit.
[0033] Next, the working process of the driving circuit will be described in detail in combination with the structures of the various units in the driving circuit.
[0034] I. Miller clamping unit
[0035] The Miller clamping unit is respectively connected to the control unit and the control unit, and is used to control the control terminal loop of the controlled switching transistor to be in a low-resistance state. Among them, the Miller clamping unit may include: a first switch and a resistor branch.
[0036] Specifically, the first end of the first switch is connected to the first end of the discharge resistor in the turning-off unit, the second end of the first switch is connected to the second end of the discharge resistor, the control terminal of the first switch is connected to the middle node of the resistor branch, and the resistor branch is connected between the first end of the discharge resistor and the control unit.
[0037] Among them, the function of setting the first switch is as follows: The first end and the second end of the first switch are respectively connected to the first end and the second end of the discharge resistor in the turn-off unit. Therefore, the first switch is in parallel with the discharge resistor. When the first switch is turned on, the discharge resistor will be short-circuited, so that the control terminal loop of the controlled switch tube is in a low-resistance state, realizing the Miller clamping function. The function of setting the resistor branch is as follows: When the turn-off unit works to establish the control terminal discharge path of the controlled switch tube, the path where the discharge resistor is located is connected to the controlled switch tube and a discharge current flows through it. Therefore, a voltage drop will be generated between the control unit at both ends of the resistor branch and the discharge resistor. The resistor branch constitutes an electric energy transmission path and charges the control terminal of the first switch connected to the intermediate node. When the control terminal of the first switch is charged to the voltage required for conduction, the first switch is turned on and the discharge resistor is short-circuited, making the control terminal loop of the controlled switch tube in a low-resistance state, thereby avoiding the situation of mis-conduction of the controlled switch tube.
[0038] It should be noted that using the resistor branch as the charging path of the first switch is only an example. In actual application, other devices with the above functions in the industry can also be used, and this application does not make too many limitations here.
[0039] In one example, the resistor branch can be composed of multiple resistors connected in series. For example, the resistor branch can include a first resistor and a second resistor. The first end of the first resistor is connected to the first end of the discharge resistor, and the second end of the first resistor is connected to the first end of the second resistor; the first end of the second resistor is connected to the control terminal of the first switch, and the second end of the second resistor is connected to the control unit.
[0040] For the convenience of understanding, a specific example of the Miller clamping unit is given below.
[0041] See Figure 2 shown, which is a schematic structural diagram of a Miller clamping unit provided by an embodiment of the present application. In Figure 2 it, the resistor R1 can be regarded as the first resistor, the resistor R2 can be regarded as the second resistor, and the S1 of the N-type MOSFET can be regarded as the first switch.
[0042] Adopt Figure 2When the shown Miller clamping unit controls the controlled switch transistor, taking the second signal for turning off the controlled switch transistor Q1 as a high-level signal as an example, when the control unit outputs the second signal, the turn-off unit operates and establishes a discharge path for the control terminal of the controlled switch transistor Q1. At this time, the output terminal of the control unit is in a high-level voltage state. This high-level voltage can be connected to the discharge resistor inside the turn-off unit through the path of the series connection of resistor R1 and resistor R2. At this time, electrical energy is transmitted on resistor R1 and resistor R2. Since the connection point of resistor R1 and resistor R2 is connected to the control terminal of switch S1, resistor R1 and resistor R2 can charge the control terminal of switch S1 through the connection point. When the voltage of the control terminal of switch S1 is charged to the voltage required for conduction, switch S1 conducts and can short-circuit the discharge resistor inside the turn-off unit, and the control terminal path of the controlled switch transistor Q1 is in a low-resistance state, thereby avoiding the situation of mis-conduction of the controlled switch transistor Q1.
[0043] It should be noted that the resistance values of resistor R1 and resistor R2 can be configured according to the resistance values of the controlled switch transistor Q1 and the discharge resistor inside the turn-off unit. For example, in order not to affect the normal turn-off process of the controlled switch transistor Q1, the resistance values of resistor R1 and resistor R2 can be configured such that the first charging time for charging the control terminal of the first switch S1 is greater than or equal to the second discharge time for discharging the control terminal of the controlled switch transistor Q1. Among them, the first time is the charging time required for the first switch S1 to conduct, and the second time is the time required for the control terminal of the controlled switch transistor Q1 to complete discharging. Therefore, adopting the above Miller clamping unit structure will perform Miller clamping after the turn-off unit controls the normal turn-off of the controlled switch transistor, thereby not affecting the normal turn-off process of the controlled switch transistor and ensuring the normal operation of the controlled switch transistor.
[0044] Of course, the above introduction to the structure of the Miller clamping unit is only an example. In actual applications, the Miller clamping unit can also adopt other structures. For example, the resistor branch in the Miller clamping unit can adopt two or more resistors or other devices in the industry with the above functions.
[0045] II. Turn-off Unit
[0046] The turn-off unit is respectively connected to the control unit, the Miller clamping unit, and the control terminal of the controlled switch transistor. The turn-off unit can discharge the control terminal of the controlled switch transistor when receiving the second signal. When the control terminal of the controlled switch transistor is discharged, the controlled switch transistor turns off. Among them, the turn-off unit can form a push-pull drive circuit with the drive unit in the drive circuit and drive the conduction and turn-off of the controlled switch transistor. Next, the process of driving the controlled switch transistor to turn off will be introduced in detail in combination with the structure of the turn-off unit.
[0047] In practical applications, the structure of the turn-off unit can adopt the commonly used push-pull drive structure topology in the industry. For example, the turn-off unit can include a third resistor, a fourth resistor, a first diode, a second switch, a fifth resistor, and a discharge resistor.
[0048] Specifically, the first end of the third resistor is connected to the control unit, and the second end of the third resistor is connected to the second end of the fourth resistor; the first end of the fourth resistor is connected to the anode of the first diode, and the second end of the fourth resistor is connected to the control end of the second switch; the cathode of the first diode is connected to the control unit; the first end of the second switch is connected to the first end of the discharge resistor; the second end of the second switch is used to be connected to the first power supply, and the control end of the second switch is connected to the first end of the fifth resistor; the second end of the fifth resistor is connected to the second end of the second switch; the first end of the discharge resistor is connected to the first end of the first switch and the first end of the first resistor, and the second end of the discharge resistor is used to be connected to the control end of the controlled switch tube.
[0049] For ease of understanding, a specific example of the turn-off unit is given.
[0050] See Figure 3 As shown, it is a schematic structural diagram of a turn-off unit provided by an embodiment of the present application. In Figure 3 it, the resistor R3 can be regarded as the third resistor, the resistor R4 can be regarded as the fourth resistor, the resistor R5 can be regarded as the fifth resistor, the diode D1 can be regarded as the first diode, the resistor Rz can be regarded as the discharge resistor, and the S2 of the N-type MOSFET can be regarded as the second switch. Among them, the power supply VEE is the first power supply used to drive the controlled switch tube Q1 to turn off.
[0051] Through Figure 3When the shown turn-off unit controls the controlled switch transistor Q1, taking the first signal for controlling the conduction of the controlled switch transistor Q1 as a low-level signal and the second signal for turning off the controlled switch transistor Q1 as a high-level signal as an example. When the control unit outputs the first signal, the control terminal of the switch S2 can be discharged through the diode D1 and the resistor R4. When the discharge of the control terminal of the switch S2 is completed, it is turned off, and the electrical connection between the power supply VEE and the controlled switch transistor Q1 is disconnected. When the control unit outputs the second signal, the second signal can charge the control terminal of the switch S2 through the resistor R3. When the voltage of the control terminal of the switch S2 is charged to the voltage required for conduction, the switch S2 conducts and forms a discharge path for the control terminal of the controlled switch transistor Q1 with the resistor Rz, and the power supply VEE drives the controlled switch transistor Q1 to turn off. At the same time, the second signal can charge the control terminal of the switch S1 through the path formed by the resistor R1 and the resistor R2. When the voltage of the control terminal of the switch S1 is charged to the voltage required for conduction, the switch S1 conducts and shorts the resistor Rz. At this time, the switch S1 and the switch S2 form a discharge path for the control terminal of the controlled switch transistor Q1. At this time, even if there is a Miller capacitance current on the line, due to the small resistance on the discharge path, the voltage drop generated by the Miller capacitance current on the above discharge path cannot meet the conduction voltage requirement of the controlled switch transistor Q1, thereby avoiding the situation of mis-conduction of the controlled switch transistor Q1.
[0052] It should be noted that the above Figure 3 shown turn-off unit structure is only an example. In actual application, the structure of the turn-off unit can select other push-pull drive structure topologies commonly used in the industry, and specific limitations are not made here in this application.
[0053] III. Driving Unit
[0054] The driving unit is respectively connected to the control unit and the control terminal of the controlled switch transistor. The driving unit can charge the control terminal of the controlled switch transistor when receiving the first signal. When the voltage of the control terminal of the controlled switch transistor is charged to the voltage required for conduction, the controlled switch transistor conducts. Among them, the driving unit can be combined with the turn-off unit in the driving circuit to form a push-pull drive circuit and drive the conduction and turn-off of the controlled switch transistor. Next, the process of driving the controlled switch transistor to conduct will be introduced in detail in combination with the structure of the driving unit.
[0055] In actual application, the structure of the driving unit can adopt a push-pull drive structure topology commonly used in the industry. For example, the driving unit can include a sixth resistor, a seventh resistor, a second diode, a third switch, an eighth resistor, and a driving resistor.
[0056] Specifically, the first end of the sixth resistor is connected to the control unit, and the second end of the sixth resistor is connected to the second end of the seventh resistor; the first end of the seventh resistor is connected to the cathode of the second diode, and the second end of the seventh resistor is connected to the control end of the third switch; the anode of the second diode is connected to the control unit; the first end of the third switch is used to be connected to the second power supply, and the second end of the third switch is connected to the first end of the drive resistor; the control end of the third switch is connected to the first end of the eighth resistor; the second end of the eighth resistor is connected to the first end of the second switch; the second end of the drive resistor is used to be connected to the control end of the controlled switch transistor.
[0057] For ease of understanding, a specific example of the drive unit is given.
[0058] See Figure 4 As shown, it is a schematic structural diagram of a drive unit provided by an embodiment of the present application. In Figure 4 it, the resistor R6 can be regarded as the sixth resistor, the resistor R7 can be regarded as the seventh resistor, the resistor R8 can be regarded as the eighth resistor, the diode D2 can be regarded as the second diode, the resistor RF can be regarded as the drive resistor, and the S3 of the P-type MOSFET can be regarded as the third switch. Among them, the power supply VCC is the second power supply used to drive the controlled switch transistor Q1 to conduct.
[0059] When controlling the controlled switch transistor Q1 through the Figure 4 drive unit shown, taking the first signal for controlling the controlled switch transistor Q1 to conduct as a low-level signal and the second signal for the controlled switch transistor Q1 to turn off as a high-level signal as an example. When the control unit outputs the first signal, the power supply VCC charges the control end of the switch S3 through the resistor R8 and the resistor R6. When the control end of the switch S3 is charged to the voltage required for conduction, the switch S3 conducts to form an electrical connection between the power supply VCC and the controlled switch transistor Q1. The power supply VCC charges the control end of the controlled switch transistor Q1 through the switch S3 and the drive resistor RF. When the control end of the controlled switch transistor Q1 is charged to the threshold voltage required for conduction, the controlled switch transistor Q1 conducts. When the control unit outputs the second signal, the control end of the switch S3 discharges through the diode D2 and the resistor R7. When the control end of the switch S3 finishes discharging, the switch S3 disconnects the electrical connection between the power supply VCC and the controlled switch transistor Q1.
[0060] It should be noted that the Figure 4 drive unit structure shown above is only an example. In actual applications, the structure of the drive unit can select other push-pull drive structure topologies commonly used in the industry, and the present application does not make specific limitations here.
[0061] Combined with the above description, an embodiment of the present application further provides a driving chip, which can be applied to an inverter and control the conduction and cutoff of the lower-arm switching transistors in the inverter. The driving chip may include a plurality of external pins and the control unit in the foregoing driving circuit. The control unit may be encapsulated in the driving chip and connected to other devices through the plurality of external pins of the driving chip.
[0062] In actual use, the driving unit, the cutoff unit, and the Miller clamping unit in the driving circuit may serve as the peripheral circuit of the driving chip and are connected to the control unit encapsulated inside the driving chip through the external pins of the driving chip. Taking Figure 4 the shown driving circuit structure as an example, the connection schematic diagram of the driving chip is as shown in Figure 5 the figure.
[0063] Combined with the above description, an embodiment of the present application further provides a driving chip, which can be applied to an inverter and control the conduction and cutoff of the lower-arm switching transistors in the inverter. The driving unit, the cutoff unit, the control unit, and the Miller clamping unit in the foregoing driving circuit are all encapsulated in the driving chip, and a plurality of external interfaces are provided on the driving chip. A plurality of devices in the driving circuit can be respectively connected to the controlled switching transistor, the first power supply, and the second power supply through the above external interfaces.
[0064] Combined with the above description, an embodiment of the present application further provides an inverter, which can be applied to a power supply system and is used to realize the conversion between the power supply voltage and the load power consumption voltage. The inverter at least includes a plurality of arms and a plurality of the foregoing driving circuits. Among them, the plurality of driving circuits may correspond to the plurality of arms one by one, and each arm can be used to control the conduction and cutoff of the lower-arm switching transistors in the corresponding arm.
[0065] It should be noted that the inverter composed of the arm and the driving circuit is only a structural topology of the inverter. In actual applications, the inverter may also have other structural topologies. For example, in addition to the above devices, the inverter may further include a energy storage inductor corresponding to each arm. The energy storage inductor and the corresponding arm can form a power factor correction (PFC) circuit to improve the working efficiency of the inverter. Of course, the conversion circuit may also adopt other topologies with the above functions in the industry, which will not be introduced one by one here in the present application.
[0066] In actual applications, the inverter may also include other functional devices. For example, the inverter also includes a protection device, and the protection device may be an overload protection device and a short-circuit protection device.
[0067] In various embodiments of the present application, if there is no special description and logical conflict, the terms and / or descriptions between different embodiments are consistent and can be cross-referenced to each other. The technical features in different embodiments can be combined to form new embodiments according to their inherent logical relationships.
[0068] Obviously, those skilled in the art can make various changes and modifications to the present application without departing from the protection scope of the present application. Thus, if these modifications and variations of the present application fall within the scope of the claims of the present application and their equivalent technologies, the present application also intends to include these changes and modifications.
Claims
1. A driving circuit, characterized in that: include: A drive unit, a shut-off unit, a control unit and a Miller clamp unit; The driving unit is connected to the control unit, and is used to be connected to the control end of the controlled switch tube, and to charge the control end of the controlled switch tube when receiving the first signal; The shutoff unit is connected to the control unit, and is used to be connected to the control end of the controlled switch tube, and discharge the control end of the controlled switch tube when receiving the second signal; The Miller clamp unit includes a first switch and a resistance branch, wherein the first end of the first switch is connected to the first end of the discharge resistor in the shutdown unit, the second end of the first switch is connected to the second end of the discharge resistor, the control end of the first switch is connected to the middle node of the resistance branch, and the resistance branch is connected between the first end of the discharge resistor and the control unit.
2. The circuit according to claim 1, characterized in that The resistance branch includes a plurality of resistors connected in series.
3. The circuit according to claim 2, characterized in that The resistance branch includes: a first resistor and a second resistor; The first end of the first resistor is connected to the first end of the discharge resistor, and the second end of the first resistor is connected to the first end of the second resistor; A first end of the second resistor is connected to a control end of the first switch, and a second end of the second resistor is connected to the control unit.
4. The circuit according to claim 3, characterized in that The shutoff unit includes: a third resistor, a fourth resistor, a first diode, a second switch, a fifth resistor and the discharge resistor; A first end of the third resistor is connected to the control unit, and a second end of the third resistor is connected to a second end of the fourth resistor; A first end of the fourth resistor is connected to the anode of the first diode, and a second end of the fourth resistor is connected to the control end of the second switch; The cathode of the first diode is connected to the control unit; The first end of the second switch is connected to the first end of the discharge resistor; the second end of the second switch is used to be connected to the first power supply, and the control end of the second switch is connected to the first end of the fifth resistor; The second end of the fifth resistor is connected to the second end of the second switch; The first end of the discharge resistor is connected to the first end of the first switch and the first end of the first resistor, and the second end of the discharge resistor is used to be connected to the control end of the controlled switch tube.
5. The circuit according to claim 4, characterized in that The driving unit includes: a sixth resistor, a seventh resistor, a second diode, a third switch, an eighth resistor and a driving resistor; A first end of the sixth resistor is connected to the control unit, and a second end of the sixth resistor is connected to a second end of the seventh resistor; A first end of the seventh resistor is connected to the cathode of the second diode, and a second end of the seventh resistor is connected to the control end of the third switch; An anode of the second diode is connected to the control unit; The first end of the third switch is used to be connected to the second power supply, and the second end of the third switch is connected to the first end of the driving resistor; the control end of the third switch is connected to the first end of the eighth resistor; The second end of the eighth resistor is connected to the first end of the second switch; The second end of the driving resistor is used to be connected to the control end of the controlled switch tube.
6. The circuit according to claim 3 or 4, characterized in that: The first time length for charging the control end of the first switch by the first resistor and the second resistor is greater than or equal to the second time length for discharging the control end of the controlled switch tube. The first time length is the charging time length required for the first switch to be turned on, and the second time length is the time length required for the control end of the controlled switch tube to be completely discharged.
7. The circuit according to claim 1 or 2, characterized in that: The controlled switch tube is an IGBT, and the switch in the driving circuit is a MOS tube.
8. A driver chip, characterized in that: The device comprises a plurality of external pins and a control unit according to any one of claims 1 to 7, wherein the driving unit, the shut-off unit and the Miller clamp unit are connected to the control unit via the external pins.
9. A driver chip, characterized in that: include: A plurality of external pins and a driving circuit as claimed in any one of claims 1 to 7, wherein the controlled switch tube is connected to the driving circuit through the plurality of external pins.
10. A converter, characterized in that: include: A plurality of bridge arms and a plurality of driving circuits as claimed in any one of claims 1 to 7, each driving circuit being used to control the on and off of a lower bridge arm switch tube in a bridge arm.