Driving circuit and automobile ignition system

Abstract

The embodiment of the invention discloses a driving circuit and an automobile ignition system, the driving circuit comprises a driving circuit input end, the driving circuit input end receives an ignition signal, the ignition signal supplies power to an internal unit of the driving circuit, the ignition signal controls a first end of a power device, and the first end of the power device is a control end of the power device. The ignition signal is not only used for driving the power device, but also used for supplying power to the driving circuit. The battery of the ignition system does not directly supply power to the driving circuit, a signal line from the battery to the driving circuit is omitted, electromagnetic interference on the driving circuit is reduced, mistaken ignition caused by unexpected current in the ignition coil is avoided, and the reliability of the ignition system is improved.

Description

Technical Field

[0001] The present invention relates to the field of integrated circuits, and particularly to a drive circuit and an automotive ignition system. Background Art

[0002] More and more electronic devices are applied to automobiles, improving the performance and comfort of the automobiles. A large amount of signal transmission between electronic devices brings electromagnetic interference. Electromagnetic interference in an automobile refers to any electromagnetic energy that interrupts, obstructs, reduces, or limits the normal operation of electronic devices in the automobile. Electromagnetic interference has a great impact on the normal operation of electronic devices in the automobile.

[0003] The ignition system (Battery - operated ignition) is an important part of a gasoline engine. In the ignition system, a power device controls the current in the ignition coil. Electromagnetic interference may cause an undesired current in the ignition coil, resulting in misfiring and causing accidents. Therefore, it is necessary to improve the reliability of the ignition system. Summary of the Invention

[0004] Embodiments of the present application provide a drive circuit and an automotive ignition system.

[0005] According to one aspect of the embodiments of the present application, a drive circuit is provided, including:

[0006] An input terminal of the drive circuit, the input terminal of the drive circuit receives an ignition signal, the ignition signal powers an internal unit of the drive circuit, and the ignition signal controls a first end of a power device, and the first end of the power device is a control end of the power device.

[0007] Optionally, the internal unit of the drive circuit includes an operational amplifier; the drive circuit further includes a third resistor and a first capacitor. A first end of the third resistor is connected to the input terminal of the drive circuit and receives the ignition signal, a second end of the third resistor serves as a first voltage node, the first capacitor is connected between the second end of the third resistor and the ground, the first voltage node is connected to the operational amplifier, and the ignition signal powers the operational amplifier through the third resistor.

[0008] Optionally, the drive circuit further includes a sixth resistor. A first end of the sixth resistor is connected to the input terminal of the drive circuit, and a second end of the sixth resistor is connected to the first end of the power device, and the ignition signal controls the conduction and cutoff of the power device through the sixth resistor.

[0009] Optionally, the internal unit of the drive circuit further includes a first voltage stabilizing circuit, the first voltage stabilizing circuit is connected between the first voltage node and the ground, and the first voltage stabilizing circuit stabilizes the voltage of the first voltage node at a first target voltage.

[0010] Optionally, the first voltage stabilizing circuit includes: a seventh resistor, an eighth resistor, and an active clamping circuit. The active clamping circuit is connected between the first voltage node and the ground. The seventh resistor and the eighth resistor are connected in series between the first voltage node and the ground. The middle node of the seventh resistor and the eighth resistor is connected to the reference terminal of the active clamping circuit. The voltage at the middle node of the seventh resistor and the eighth resistor is V REF , and the active clamping circuit stabilizes the voltage of the first voltage node N1 to:

[0011] V REF is the voltage at the middle node of the seventh resistor and the eighth resistor, R7 is the resistance value of the seventh resistor, and R8 is the resistance value of the eighth resistor.

[0012] Optionally, the internal unit of the drive circuit further includes a second voltage stabilizing circuit. The second voltage stabilizing circuit is connected between the first end of the power device and the ground. When the ignition signal is at a high voltage, the second voltage stabilizing circuit stabilizes the voltage between the first end of the power device and the ground at a second target voltage to protect the first end of the power device. The second end of the power device is connected to the ignition coil. The ground end of the drive circuit is grounded, and the third end of the power device is grounded.

[0013] Optionally, the second voltage stabilizing circuit is a Zener diode. The cathode of the Zener diode is connected to the first end of the power device, and the anode of the Zener diode is grounded.

[0014] Optionally, the drive circuit further includes a fourth resistor and a fifth resistor connected in series between the input terminal and the ground. The node between the fourth resistor and the fifth resistor is the second sampling node;

[0015] The internal unit of the drive circuit further includes a protection circuit. The first input terminal of the protection circuit receives a temperature feedback signal. The second input terminal of the protection circuit is connected to the second sampling node and receives a voltage sampling signal. The output terminal of the protection circuit is connected to the second input terminal of the operational amplifier.

[0016] Optionally, the protection circuit includes a trigger signal generation circuit and a linear current generation circuit. The first input terminal of the trigger signal generation circuit receives a temperature feedback signal. The second terminal of the trigger signal generation circuit is connected to the second sampling node and receives a voltage sampling signal. The input terminal of the linear current generation circuit is connected to the output terminal of the trigger signal generation circuit. The output terminal of the linear current generation circuit is connected to the second input terminal of the operational amplifier. When the trigger condition is met, the trigger signal generation circuit generates a trigger signal, and the linear current generation circuit outputs a soft turn-off control current, and the soft turn-off control current increases linearly.

[0017] Optionally, the trigger signal generation circuit includes a first comparator. The first input terminal of the first comparator is connected to a second reference voltage, and the second input terminal is connected to a second sampling node. When the voltage sampling signal of the second sampling node is greater than the second reference voltage, the trigger signal generation circuit generates a trigger signal.

[0018] Optionally, the trigger signal generation circuit includes a second comparator. The first input terminal of the second comparator receives a third reference voltage, and the second input terminal is connected to a temperature-sensitive element. The temperature-sensitive element detects the temperature of the power device and generates a temperature feedback signal. When the temperature feedback signal provided by the temperature-sensitive element is less than the third reference voltage, the trigger signal generation circuit generates a trigger signal.

[0019] Optionally, a first transistor, the second terminal and the third terminal of the first transistor are respectively connected to the first terminal of the power device and the ground;

[0020] A first sampling circuit, the first terminal of the first sampling circuit is connected to the third terminal of the power device, and the second terminal of the first sampling circuit is grounded;

[0021] The first input terminal of the operational amplifier receives a first reference voltage, the second input terminal of the operational amplifier is connected to the first terminal of the first sampling circuit, and the output terminal of the operational amplifier is connected to the first terminal of the first transistor.

[0022] Optionally, the power device is an IGBT or an RC-IGBT. The first terminal of the power device is the gate, the second terminal is the collector, and the third terminal is the emitter; or the power device is a MOSFET, the first terminal of the power device is the gate, the second terminal is the drain, and the third terminal is the source.

[0023] Optionally, the drive circuit further includes a feedback circuit. The feedback circuit is a feedback resistor with a resistance value in the order of kilo-ohms, and the first sampling circuit is a first sampling resistor with a resistance value in the order of milli-ohms.

[0024] Optionally, the drive circuit and the power device are packaged in a packaging structure, and the packaging structure includes:

[0025] A packaging substrate, the first surface of the packaging substrate has a base island, and the drive circuit and the power device are located on the base island. Among them, the drive circuit is isolated from the base island through an insulating layer.

[0026] Optionally, the drive circuit and the power device are packaged in a packaging structure, and the packaging structure includes:

[0027] A packaging substrate, the first surface of the packaging substrate has a first base island and a second base island that are isolated from each other. The drive circuit is located on the first base island, and the power device is located on the second base island.

[0028] Optionally, the input end of the drive circuit is connected to the input pin, the second end of the power device is connected to the collector pin, and the ground end of the drive circuit and the third end of the power device are connected to the ground pin.

[0029] Optionally, the collector pin, the input pin, and the ground pin are located on the same side of the package structure.

[0030] Optionally, the package structure has only the collector pin, the input pin, and the ground pin.

[0031] Optionally, the second end of the power device is mounted on the base island.

[0032] Optionally, the second end of the power device is mounted on the second base island.

[0033] Optionally, the package structure further includes: a temperature-sensitive element for detecting the temperature of the power device. The temperature-sensitive element and the power device are located on the same base island. The two ends of the temperature-sensitive element are electrically connected to the second end and the third end of the power device, and the two ends of the temperature-sensitive element are connected to the drive circuit and provide a temperature feedback signal to the drive circuit.

[0034] Optionally, the third end of the power device is electrically connected to the ground pin through a bonding wire, and the bonding wire is equivalent to a first sampling resistor.

[0035] Optionally, the first reference voltage and the first sampling circuit have a positive temperature coefficient.

[0036] Optionally, the soft turn-off control current has a positive temperature coefficient.

[0037] Optionally, the feedback resistor has a zero temperature coefficient.

[0038] Optionally, when the triggering condition is met, the trigger signal generation circuit delays for a predetermined time to output a trigger signal.

[0039] Optionally, the ignition signal is provided to the input end of the drive circuit by the battery through the conversion of the controller.

[0040] According to another aspect of the embodiments of the present application, there is provided an automotive ignition system, including:

[0041] A controller;

[0042] An ignition coil;

[0043] A battery that outputs an electrical signal and supplies power to the ignition coil and the controller. The controller receives the electrical signal and converts it into an ignition signal;

[0044] A power switch; the second end of the power switch is connected to the ignition coil, and the third end of the power switch is grounded; and

[0045] The aforementioned drive circuit.

[0046] Preferably, the drive circuit is not directly connected to the battery.

[0047] According to the present application, the battery outputs an electrical signal and powers the ignition coil and the controller. The controller receives the electrical signal output by the battery and generates an ignition signal. The input terminal of the drive circuit is connected to the controller and receives the ignition signal, and the ignition signal powers the internal unit of the drive circuit. The drive circuit is connected to the first end of the power device, and the drive circuit controls the conduction and cutoff of the power device. The second end of the power device is connected to the ignition coil, and the third end of the power device is grounded. The ignition signal of the present application is not only used to drive the power device, but also used to power the drive circuit.

[0048] The first transistor, the power device, the feedback resistor, the first sampling circuit and the operational amplifier limit the maximum value of the current of the power device to I C_MAX , reducing the overcurrent risk. Further, the first reference voltage and the first sampling resistor have a positive temperature coefficient. Therefore, the maximum value I C_MAX of the current flowing through the power device has a zero temperature coefficient, avoiding the maximum value I C_MAX of the current flowing through the power device from becoming too large due to an increase in temperature, thereby avoiding an undesired current in the ignition coil, resulting in misfiring and causing an accident.

[0049] When the trigger condition is satisfied, the linear current generation circuit outputs a soft turn-off control current. Due to the effect of the negative feedback loop, the current of the power device is determined by the soft turn-off control current, the first reference voltage, the feedback resistor and the first sampling resistor. As the soft turn-off control current gradually increases, the current of the power device gradually decreases, realizing the soft turn-off of the power device. Further, the soft turn-off control current and the first sampling resistor have a positive temperature coefficient, and the feedback resistor has a zero temperature coefficient. Therefore, the current flowing through the power device has a zero temperature coefficient. Description of the Drawings

[0050] Through the following description of the embodiments of the present application with reference to the drawings, the above and other objects, features and advantages of the present application will become clearer. In the drawings:

[0051] Figure 1 A schematic diagram of an automotive ignition system according to an embodiment of the present application is shown;

[0052] Figure 2 The package structure of the power device and the drive circuit is shown;

[0053] Figure 3 A circuit diagram of the drive circuit according to an embodiment of the present application is shown;

[0054] Figure 4 A circuit diagram of the first voltage stabilization circuit according to an embodiment of the present application is shown;

[0055] Figure 5Shows the circuit diagram of the second voltage stabilizing circuit according to an embodiment of the present application;

[0056] Figure 6 Shows the exemplary ignition process waveform diagram of the automotive ignition system according to an embodiment of the present application;

[0057] Figure 7 Shows the circuit diagram of the driving circuit according to another embodiment of the present application;

[0058] Figure 8 Shows the circuit diagram of the trigger signal generation circuit according to an embodiment of the present application;

[0059] Figure 9 Shows the setting of the exemplary temperature-sensitive element according to an embodiment of the present application;

[0060] Figure 10 Shows the circuit diagram of the reference voltage generation circuit according to an embodiment of the present application;

[0061] Figure 11 Shows the soft turn-off process waveform diagram of the automotive ignition system according to an embodiment of the present application. Detailed implementation manners

[0062] The following describes the present invention based on embodiments, but the present invention is not limited to these embodiments. In the following detailed description of the present invention, some specific details are described in detail. Those skilled in the art can fully understand the present application without the description of these details. In order to avoid obscuring the essence of the present application, well-known methods, processes, procedures, elements, and circuits are not described in detail.

[0063] In addition, those of ordinary skill in the art should understand that the drawings provided herein are for illustrative purposes only, and the drawings are not necessarily drawn to scale.

[0064] Unless the context clearly requires otherwise, the words "including", "comprising", and the like throughout the specification of the application should be construed in an inclusive sense rather than an exclusive or exhaustive sense; that is, they are to be interpreted as "including but not limited to".

[0065] In the description of the present invention, it should be understood that the terms "first", "second", etc. are only used for descriptive purposes and cannot be construed as indicating or implying relative importance. In addition, in the description of the present application, unless otherwise specified, the meaning of "a plurality" is two or more.

[0066] Figure 1 Is a schematic diagram of the automotive ignition system according to an embodiment of the present invention. This automotive ignition system is applied to an automobile and is used to start the engine of the automobile. The automobile is, for example, a fuel vehicle. As Figure 1As shown, the automotive ignition system includes: a drive circuit 100, a controller 200, a battery 300, a power device 400, and an ignition coil 500.

[0067] The battery 300 outputs an electrical signal and supplies power to the ignition coil 500 and the controller 200; the controller 200 receives the electrical signal output by the battery 300 and converts it into an ignition signal VIN. The input end of the drive circuit is connected to the controller 200 and receives the ignition signal VIN. The ignition signal VIN powers the drive circuit 100. The drive circuit 100 is connected to the first end of the power device 400, and the drive circuit 100 controls the conduction and turn-off of the power device 400. The second end of the power device 400 is connected to the ignition coil 500, and the third end of the power device 400 is grounded.

[0068] The battery 300 is, for example, a storage battery. The ignition coil 500 is also called a transformer. The ignition coil 500 includes a primary coil and a secondary coil. One end of the primary coil is connected to the anode of the battery 300, and the other end is connected to the second end of the power device 400. A diode is also provided between the secondary coil and the anode of the battery 300. One end of the secondary coil is connected to the anode of the battery 300 through the diode, and the other end is connected to the spark plug 600.

[0069] The ignition signal VIN is, for example, a voltage pulse signal. The ignition signal controls the first end of the power device 400 to turn on the power device 400 and generate a current in the primary coil. When the voltage pulse ends, the power device 400 disconnects.

[0070] The power device 400 and the primary coil are connected in series between the anode of the battery 300 and the ground. When the power device 400 is turned on, current flows through the primary coil and the power device 400. The power device 400 is, for example, an Insulated Gate Bipolar Transistor (IGBT), an RC-IGBT, a Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), etc. The first end of the power device 400 is connected to the output end of the drive circuit 100, the second end is connected to the first end of the primary coil, and the third end is grounded. When the power device 400 is an IGBT, the first end of the power device 400 is the gate, the second end is the collector, and the third end is the emitter. When the power device 400 is a MOSFET, the first end of the power device 400 is the gate, the second end is the drain, and the third end is the source.

[0071] In the embodiments of the present application, the ignition signal VIN provided by the controller 200 is also used to power the drive circuit 100, that is, the drive circuit 100 is not directly connected to the battery 300. The drive circuit 100 includes several internal units for improving the working reliability of the power device 400, and these internal units are powered by the ignition signal VIN. The ignition signal VIN is a drive signal for controlling the conduction of the power device 400 and is also a power supply signal for the drive circuit 100.

[0072] In the prior art, the drive circuit 100 is powered by the battery. The battery 300 and the drive circuit 100 are connected by a long signal line, and the signal line between the battery 300 and the drive circuit 100 is vulnerable to electromagnetic interference. The electromagnetic interference couples voltage pulses on the signal line between the controller 200 and the drive circuit 100, causing misfiring.

[0073] In the present application, the battery 300 does not directly power the drive circuit 100, eliminating the signal line and reducing the electromagnetic interference received by the drive circuit 100, thus improving the reliability of the vehicle ignition system.

[0074] The drive circuit 100 and the power device 400 are different chips. In some embodiments, the drive circuit 100 and the power device 400 are packaged together. As Figure 2 shown, the drive circuit 100 and the power device 400 are arranged in the same packaging structure to form a packaging structure 700. The packaging structure 700 includes an input pin IN, a ground pin GND, and a collector pin (drain pin) C. The input terminal Pin of the drive circuit 100 is connected to the input pin IN through a bonding wire 6, and the output terminal Pg1 of the drive circuit 100 is connected to the first terminal Pg2 of the power device 400 through a bonding wire 1. The ground terminal Pgnd of the drive circuit 100 is connected to the ground pin GND through a bonding wire 5. The third terminal of the power device 400 is connected to a terminal Pe, and the terminal Pe is connected to the ground pin GND through a bonding wire 8.

[0075] The packaging structure 700 includes a packaging substrate.

[0076] In some embodiments, there is a base island on the first surface of the packaging substrate. The drive circuit 100 and the power device 400 are located on the base island. Among them, the drive circuit 100 is isolated from the base island through an insulating layer, and the second terminal of the power device 400 is in contact with the base island.

[0077] In some embodiments, the first surface of the packaging substrate may also be a first base island and a second base island that are isolated from each other. The drive circuit 100 and the power device 400 are respectively located on the first base island and the second base island, and the second terminal of the power device 400 is in contact with the second base island.

[0078] As Figure 2As described above, in some embodiments, the collector pin C, the input pin IN, and the ground pin GND are located on the same side of the package structure 700. Moreover, the package structure 700 has only three pins, namely the collector pin C, the input pin IN, and the ground pin GND. The structure of this package structure is simple, which provides convenience for users.

[0079] The package structure 700 further includes a temperature-sensitive element 401. The temperature-sensitive element 401 is located on the same base island as the power device 400, and both ends of the temperature-sensitive element 401 are electrically connected to the driving circuit 100. The temperature-sensitive element 401 is used to detect the temperature of the power device 400.

[0080] In some embodiments, as Figure 3 shown, the driving circuit 100 includes a driving circuit input terminal Pin. The driving circuit input terminal Pin receives the ignition signal VIN and supplies power to the internal unit of the driving circuit 100. The ignition signal VIN controls the first-end gate of the power device 400, and the first end of the power device 400 is the control end of the power device.

[0081] In some embodiments, as Figure 3 shown, the internal unit of the driving circuit 100 includes an operational amplifier 115 and a third resistor R3. The first end of the third resistor R3 is connected to the input terminal Pin of the driving circuit 100 and receives the ignition signal VIN. The second end of the third resistor R3 serves as a first voltage node N1. The first voltage node N1 is connected to the operational amplifier 115, and the ignition signal VIN supplies power to the operational amplifier 115 through the third resistor R3.

[0082] The driving circuit 100 further includes a sixth resistor R6. The first end of the sixth resistor R6 is connected to the input terminal of the driving circuit 100, and the second end of the sixth resistor R6 is connected to the first end of the power device 400. The ignition signal VIN controls the conduction and turn-off of the power device 400 through the sixth resistor R6. The sixth resistor R6 makes the gate voltage of the power device 400 more stable, meets the electromagnetic compatibility requirements under vehicle regulations, and avoids the occurrence of malfunction caused by noise such as BCI tests.

[0083] In some embodiments, as Figure 3 shown, the driving circuit 100 further includes a first capacitor C1. The second end of the first capacitor C1 is grounded, and the second end of the third resistor R3 is connected to the first end of the first capacitor C1 at the first voltage node N1.

[0084] Specifically, a third resistor R3 is connected between the input terminal Pin and the first voltage node N1, and a first capacitor C1 is connected between the first voltage node N1 and the ground. The voltage VCC of the first voltage node N1 is the voltage after RC filtering and is used to supply power to the operational amplifier 115. The third resistor R3 and the first capacitor C1 form an RC filter circuit to reduce the interference in the voltage VCC of the first voltage node N1, enabling the operational amplifier 115 to operate stably.

[0085] In some embodiments, as Figure 3 shown, the internal unit of the driving circuit 100 further includes a first voltage stabilizing circuit 120. The first voltage stabilizing circuit 120 is connected between the first voltage node N1 and the ground, and the first voltage stabilizing circuit 120 stabilizes the voltage of the first voltage node N1 at a first target voltage.

[0086] In some embodiments, as Figure 4 shown, the first voltage stabilizing circuit 120 includes a seventh resistor R7, an eighth resistor R8, and an active clamping circuit 121. Among them, the active clamping circuit 121 is connected between the first voltage node N1 and the ground. The seventh resistor R7 and the eighth resistor R8 are connected in series between the first voltage node N1 and the ground, and the middle node of the seventh resistor R7 and the eighth resistor R8 is connected to the reference terminal of the active clamping circuit 121. The voltage at the middle node of the seventh resistor R7 and the eighth resistor R8 is V REF , and the active clamping circuit 121 stabilizes the voltage VCC of the first voltage node N1 to:

[0087]

[0088] where V REF is the voltage at the middle node of the seventh resistor R7 and the eighth resistor R8, R7 is the resistance value of the seventh resistor, and R8 is the resistance value of the eighth resistor.

[0089] In some embodiments, as Figure 3 shown, the internal unit of the driving circuit further includes a second voltage stabilizing circuit 130. The second voltage stabilizing circuit 130 is connected between the first end of the power device 400 and the ground. When the ignition signal VIN is at a high voltage, the second voltage stabilizing circuit 130 stabilizes the voltage between the first end of the power device 400 and the ground at a second target voltage to protect the first end of the power device 400. The second end of the power device 400 is connected to the ignition coil 500, the ground end of the driving circuit 100 is grounded, and the third end of the power device 400 is grounded.

[0090] In some embodiments, as Figure 5 shown, the second voltage stabilizing circuit 130 is a Zener diode D1. The cathode of the Zener diode D1 is connected to the first end of the power device 400, and the anode of the Zener diode D1 is grounded.

[0091] In some embodiments, such as Figure 3 shown, the driving circuit 100 further includes a first sampling circuit 160. In this embodiment, the first sampling circuit 160 is a first sampling resistor R1. The driving circuit 100 and the third terminal of the power device 400 are electrically connected to the ground pin through a bonding wire 8, and this bonding wire is equivalent to the first sampling resistor R1, reducing the use of components.

[0092] In some embodiments, such as Figure 3 shown, the driving circuit 100 further includes a first transistor M1. The first terminal of the first transistor M1 is connected to the output terminal of the operational amplifier 115, the second terminal of the first transistor M1 is connected to the first terminal of the power device 400, and the third terminal of the first transistor M1 is grounded. The first terminal of the first sampling resistor R1 is connected to the third terminal of the power device 400, and the second terminal of the first sampling resistor R1 is grounded. The first input terminal of the operational amplifier 115 receives a first reference voltage VOCP, the second input terminal of the operational amplifier 115 is connected to the first terminal of the first sampling resistor R1, and the output terminal of the operational amplifier 115 is connected to the first terminal of the first switching transistor M1. For example, the first input terminal of the operational amplifier 115 is the inverting input terminal, and the second input terminal is the non-inverting input terminal. The first switching transistor M1 is, for example, an NMOSFET or a BJT. The operational amplifier 115 is powered by a first voltage node N1.

[0093] Figure 6 An exemplary ignition process of the automotive ignition system according to an embodiment of the present application is shown. Figure 6 Two ignition processes are shown: time period T01 and time period T02. In Figure 6 VG is the gate voltage of the power device 400, and VC is the collector voltage of the power device 400. The ignition signal VIN is a square wave with a high level time of 4 ms.

[0094] In time period T01, the ignition signal VIN is less affected by electromagnetic interference, and the voltage of the ignition signal VIN is stable. In time period T02, the ignition signal VIN is more affected by electromagnetic interference, and the voltage of the ignition signal VIN has large fluctuations. The sixth resistor R6 stabilizes the gate voltage VG of the power device 400. Due to the filtering effect of the third resistor R3 and the first capacitor C1 and the effect of the first voltage stabilizing circuit 120, the voltage VCC of the first voltage node N1 is stable.

[0095] As Figure 6 shown, when the driving circuit 100 and the power device 400 receive the ignition signal VIN, the gate voltage VG of the power device 400 is quickly pulled high to a high level by the ignition signal VIN, the voltage VCC is established, and the current I of the power device 400 C gradually increases, and the current I CThe increasing speed is related to the coil inductance. After a predetermined time, the ignition signal VIN becomes 0, the gate voltage VG of the power device 400 and the voltage VCC become 0, the power device 400 turns off, and the current I flowing through the power device 400 C becomes 0. There is still charge in the primary coil. The collector voltage VC of the power device 400 rapidly rises to a high level. The collector voltage VC of the power device 400 is coupled to the secondary coil to break down the spark plug 600 to generate a spark, ignite the combustible gas in the cylinder, and start the engine.

[0096] As Figure 3 shown, the operational amplifier 115, the first transistor M1, and the first sampling resistor R1 limit the current I flowing through the power device 400 C When the high-level duration of the ignition signal VIN is relatively long or the voltage of the ignition signal VIN is relatively high, it is necessary to limit the current I flowing through the power device 400 C to prevent the current flowing through the power device 400 from reaching the saturation current and avoid damage to the device due to excessive primary energy during ignition.

[0097] The following introduces the current-limiting principle of the negative feedback loop:

[0098] The controller 200 provides the ignition signal VIN to the input terminal Pin of the drive circuit 100. The gate voltage VG of the power device 400 is rapidly pulled up to a high level by the ignition signal VIN, the voltage VCC is established, and the current I flowing through the power device 400 C gradually increases. The voltage VP at the second input terminal of the operational amplifier 115 is I C *R1. Therefore, the voltage VP at the second input terminal of the operational amplifier 115 gradually increases. The current I flowing through the power device and the voltage VP gradually increase. The negative feedback loop limits the maximum value of the voltage VP at the second input terminal of the operational amplifier 115 to the first reference voltage VOCP. Due to the effect of the negative feedback loop, the maximum value of the voltage VP at the second input terminal of the operational amplifier 115 is the first reference voltage VOCP, and the maximum value of the current I flowing through the power device 400 C is I C = VOCP / R1. Therefore, the negative feedback loop provides overcurrent protection for the power device 400. Further, the value of I C_MAX can be limited by configuring the magnitudes of the first reference voltage VOCP and the first sampling resistor R1. C_MAX

[0099] In Figure 6 , before the current I of the power device 400 C increases to the maximum value I C_MAX , the ignition signal VIN becomes 0. ​

[0100] In some embodiments, both the first reference voltage VOCP and the first sampling resistor R1 have a positive temperature coefficient, such that the maximum current I C_MAX = VOCP / R1 has a zero temperature coefficient.

[0101] Figure 7 The circuit diagram of the driving circuit 100 according to another embodiment of the present application is shown. Figure 7 of the driving circuit 100 and Figure 3 The same parts of the driving circuit 100 will not be described in detail. As Figure 7 shown, the internal units of the driving circuit 100 further include: a protection circuit 110, a feedback circuit R2, a fourth resistor R4, and a fifth resistor R5.

[0102] The first input terminal of the protection circuit 110 receives the temperature feedback signal V SEN , and the second input terminal is connected to the second sampling node N2 and receives the voltage sampling signal V SAM . The output terminal of the protection circuit is connected to the second input terminal of the operational amplifier 115.

[0103] The fourth resistor R4 and the fifth resistor R5 are connected in series between the input terminal and the ground, and the node between the fourth resistor R4 and the fifth resistor R5 is the second sampling node N2. Therefore, the voltage V SAM of the second sampling node N2 is proportional to the ignition signal VIN and can represent the voltage magnitude of the ignition signal VIN. The first end of the feedback resistor R2 is connected to the second input terminal of the operational amplifier 115, and the second end of the feedback resistor R2 is connected to the first end of the first sampling resistor R1.

[0104] The protection circuit 110 includes a trigger signal generation circuit 113 and a linear current generation circuit 111. The first input terminal of the trigger signal generation circuit 113 receives the temperature feedback signal V SEN , the second terminal of the trigger signal generation circuit 113 is connected to the second sampling node N2 and receives the voltage sampling signal V SAM , the input terminal of the linear current generation circuit 111 is connected to the output terminal of the trigger signal generation circuit 113, and the output terminal of the linear current generation circuit 111 is connected to the second input terminal of the operational amplifier 115. When the trigger condition is satisfied, the linear current generation circuit 111 outputs a soft shutdown control current I SS , and at the same time, the soft shutdown control current I SS increases linearly. Both the linear current generation circuit 111 and the trigger signal generation circuit 113 are powered by the voltage VCC of the first voltage node N1.

[0105] As Figure 7 shown, the trigger signal generation circuit 113 receives the voltage V SAM of the second sampling node N2 and the temperature feedback voltage VSEN The temperature feedback voltage V SEN represents the temperature of the power device 400. The trigger signal generation circuit 113 generates a trigger signal SSD based on the sampled voltage V SAM and the temperature feedback voltage V SEN .

[0106] Figure 8 is a circuit diagram of an exemplary trigger signal generation circuit 113. As Figure 8 shown, the trigger signal generation circuit 113 includes: a first comparator 1131 and a second comparator 1132.

[0107] The first input terminal of the first comparator 1131 is connected to the second reference voltage VOVP, and the second input terminal is connected to the second sampling node N2. The first comparator 1131 compares the sampled voltage V SAM and the second reference voltage VOVP. When the sampled voltage V SAM is greater than the second reference voltage VOVP, it indicates that the voltage at the input terminal Pin is greater than the preset voltage value, and the first comparator 1131 outputs a first level (e.g., high level). When the sampled voltage V SAM is less than the second reference voltage VOVP, it indicates that the voltage at the input terminal Pin is less than the preset voltage value, and the voltage is within the acceptable range, and the first comparator 1131 outputs a second level (e.g., low level). This preset voltage value is greater than the voltage of the ignition signal VIN.

[0108] The first input terminal of the second comparator 1132 is connected to the third reference voltage VOTP, and the second input terminal of the second comparator 1132 is connected to the temperature-sensitive element 401. The temperature-sensitive element 401 is used to detect the temperature of the power device 400. The voltage difference across the temperature-sensitive element 401 is used as the temperature feedback voltage, and the temperature feedback voltage V SEN represents the temperature of the power device 400, and the voltage at the second input terminal of the second comparator 1132 is equal to this temperature feedback voltage V SEN . The temperature-sensitive element 401 is, for example, connected between the second input terminal of the second comparator 1132 and the ground. When the temperature of the power device 400 changes, the voltage difference across the temperature-sensitive element 401 changes. The temperature-sensitive element 401 is, for example, a thermistor, a temperature-sensitive diode, etc.

[0109] Figure 9 shows an exemplary temperature-sensitive element 401. The temperature-sensitive element 401 and the power device 400 are fabricated together. The temperature-sensitive element 401 is a temperature-sensitive diode D2. Refer to Figure 2 , Figure 7 and Figure 9, the anode of the temperature-sensitive diode D2 is connected to the terminal Pdp2 of the power device, and the cathode of the temperature-sensitive diode D2 is connected to the terminal Pdn2 of the power device. The terminal Pdp2 is connected to the terminal Pdp1 of the drive circuit 100 through the bonding wire 2, and the terminal Pdp1 is also connected to the second input terminal of the second comparator 1132. The terminal Pdn2 is connected to the terminal Pdn1 of the drive circuit 100 through the bonding wire 3, and the terminal Pdn1 of the drive circuit 100 is also connected to the ground terminal Pgnd of the drive circuit 100. The second end of the feedback circuit R2 of the drive circuit 100 is connected to the terminal Ps of the drive circuit 100, and the terminal Ps of the drive circuit 100 is connected to the terminal Pe of the power device 400 through the bonding wire 4. The third end of the power device 400 is connected to the terminal Pe, and the terminal Pe is grounded through the bonding wire 8. The bonding wire 8 serves as the first sampling resistor R1. The output terminal Pg1 of the drive circuit 100 is connected to the first end Pg2 of the power device 400 through the bonding wire 1. When the temperature of the power device 400 increases, the voltage difference across the temperature-sensitive diode D2 decreases. When the voltage at the second input terminal of the second comparator 1132 is less than the third reference voltage VOTP, it indicates that the temperature at the power device 400 is greater than the preset temperature value, and the second comparator 1132 outputs a first level (e.g., high level). When the voltage at the second input terminal of the second comparator 1132 is greater than the third reference voltage VOTP, it indicates that the temperature at the power device 400 is less than the preset temperature value, and the second comparator 1132 outputs a second level (e.g., low level).

[0110] When one of the first comparator 1131 and the second comparator 1132 outputs a first level, the trigger signal generation circuit 113 outputs a trigger signal SSD. For example, the trigger signal generation circuit 113 further includes an OR gate, and the two input terminals of the OR gate are respectively connected to the output terminal of the first comparator 1131 and the output terminal of the second comparator 1132.

[0111] In some embodiments, the second reference voltage VOVP and the third reference voltage VOTP are equal, which can simplify the circuits for generating the second reference voltage VOVP and the third reference voltage VOTP. For example, the ratio of the sampling voltage V SAM and the ignition signal VIN can be adjusted by configuring the ratio of the fourth resistor R4 and the fifth resistor R5, so as to adapt to the magnitude of the second reference voltage VOVP.

[0112] The trigger conditions include that the voltage at the input terminal IN (the voltage of the ignition signal VIN) is greater than a preset voltage value, and / or the temperature of the power device 400 is greater than a preset temperature value. For example, when one of the voltage at the input terminal IN being greater than the preset voltage value and the temperature of the power device 400 being greater than the preset temperature value occurs, the trigger signal generation circuit 113 outputs a trigger signal. At this time, Figure 7 the shown drive circuit 100 can provide overvoltage protection and overcurrent protection.

[0113] In response to the triggering condition being satisfied, the trigger signal generation circuit 113 outputs a trigger signal SSD, and then the linear current generation circuit 111 outputs a soft turn-off control current I SS . The soft turn-off control current I SS flows through the feedback resistor R2 and the first sampling resistor R1 to the ground.

[0114] In some embodiments, after a predetermined time delay after the triggering condition is satisfied, the linear current generation circuit 111 outputs the soft turn-off control current I SS . That is, after a predetermined time delay after the triggering condition is satisfied, the soft turn-off is started to avoid mis-triggering of the soft turn-off by a short voltage pulse at the input pin IN. For example, the delayed start of the soft turn-off can be achieved in the following two ways.

[0115] In one implementation, the trigger signal generation circuit 113 outputs the trigger signal SSD after a predetermined time delay. As Figure 8 shown, the trigger signal generation circuit 113 further includes a delay circuit 1134. When the first comparator 1131 determines that the voltage of the ignition signal VIN is too high, or when the second comparator 1132 determines that the temperature of the power device 400 is too high, the delay circuit 1134 causes the trigger signal generation circuit 113 to generate the trigger signal SSD after a predetermined time delay.

[0116] In some embodiments, one or more of the first reference voltage VOCP, the second reference voltage VOVP, and the third reference voltage VOTP are generated by a reference voltage generation circuit. As Figure 10 shown, the drive circuit 100 further includes a first reference voltage generation circuit 151 and a second reference voltage generation circuit 152. The first reference voltage generation circuit 151 is, for example, based on a bandgap reference. The voltage VCC provided by the first voltage node N1 powers the first reference voltage generation circuit 151 and the second reference voltage generation circuit 152. The bandgap reference source includes, for example, a sub-circuit that generates a positive temperature coefficient (PTAT) current and a sub-circuit that generates a negative temperature coefficient (CTAT) current. By superimposing the PTAT current and the CTAT current, a zero temperature coefficient current is obtained, and then a zero temperature coefficient voltage is obtained according to the zero temperature coefficient current. A positive temperature coefficient voltage can be obtained according to the PTAT current.

[0117] In some embodiments, the first reference voltage VOCP has a positive temperature coefficient and is generated by the second reference voltage generating circuit 152, and the second reference voltage VOVP and the third reference voltage VOTP have zero temperature coefficients and are generated by the first reference voltage generating circuit 151.

[0118] In the embodiments of the present application, when one of the two situations of overvoltage of the input voltage and overtemperature of the power device 400 occurs, the trigger condition is satisfied and soft shutdown is triggered. The trigger signal generating circuit 113, the linear current generating circuit 111, the operational amplifier 115 and the first transistor M1 can implement overvoltage protection and overtemperature protection.

[0119] When the trigger condition is satisfied, the trigger signal generating circuit 113 generates a trigger signal SSD, and the linear current generating circuit 111 generates a linearly increasing soft shutdown control current I SS , and the soft shutdown control current I SS flows through the feedback resistor R2 and the first sampling resistor R1. The voltage VP at the second input terminal of the operational amplifier 115 is:

[0120] VP = I SS *R2 + (I SS + I C )*R1 (2)

[0121] The voltage VP at the second input terminal of the operational amplifier 115 gradually increases to the first reference voltage VOCP, and the current I C of the power device 400 is:

[0122]

[0123] In the embodiments of the present application, the resistance value of the feedback resistor R2 is much larger than the resistance value of the first sampling resistor R1, and the soft shutdown control current I SS generated by the linear current generating circuit 111 is small. Therefore, the current I C of the power device 400 is approximately:

[0124]

[0125] For example, the resistance value of the first sampling resistor R1 is in the milliohm level, and the resistance value of the feedback resistor R2 is in the kiloohm level.

[0126] As the soft shutdown control current I SS gradually increases, the current I C of the power device 400 gradually decreases, and the decreasing rate of the current I C is determined by the increasing rate of the current I SS , realizing the soft shutdown of the power device 400.

[0127] In some embodiments, the soft - turn - off control current I generated by the linear current generation circuit 111 SS and the first resistor R1 both have a positive temperature coefficient, the first reference voltage VOCP has a positive temperature coefficient, and the feedback circuit R2 has a zero temperature coefficient. Therefore, during the soft - turn - off process, the current I of the power device 400 C also has a zero temperature coefficient. Thus, even when the driving circuit and the power device are at a relatively high temperature, the current I C does not decrease too rapidly.

[0128] The following takes the Figure 7 shown driving circuit 100 as an example to describe the working process of soft - turn - off. Figure 11 shows the voltage changes of multiple nodes of the driving circuit 100 during the soft - turn - off process. In Figure 11 , VG is the gate voltage of the power device 400, and OVP is the output signal of the first comparator 1131.

[0129] The voltage V of the input terminal IN of the driving circuit 100 IN abnormally rises (greater than the preset voltage value) at time t1, triggering over - voltage protection. When the triggering condition is satisfied, the output signal OVP of the first comparator 1131 becomes high level.

[0130] During the first period T1 (from time t1 to time t2), the gate voltage VG of the power device 400 is rapidly pulled up by the input terminal voltage V IN . Since the second terminal C of the power device 400 is connected to the primary - side coil inductance, the current I of the power device 400 C gradually increases. The current I C flows through the first sampling circuit R1. The voltage VP at the second input terminal of the operational amplifier 115 = I C *R1, and the voltage VP gradually increases as the current I C increases. During the first period T1, the voltage VOCP at the first input terminal of the operational amplifier 115 is greater than the voltage VP at the second input terminal, and the voltage difference is large. During the first period T1, the output of the operational amplifier 115 is low level, the first transistor M1 is turned off, and the gate voltage VG of the power device 400 remains high level.

[0131] As the voltage VP at the second input terminal of the operational amplifier 115 increases, the voltage difference between the first input terminal and the second input terminal of the operational amplifier 115 gradually decreases. At time t2, the output voltage of the operational amplifier 115 is equal to the threshold voltage of the first transistor M1.

[0132] During the second time period T2 (from time t2 to time t3), the output voltage of the operational amplifier 115 is greater than the threshold voltage of the first transistor M1 and gradually increases. The first switching transistor M1 gradually turns on, and the gate voltage VG of the power device 400 gradually decreases. At time t3, the voltage VP at the second input terminal of the operational amplifier 115 is equal to the voltage VOCP at the first input terminal of the operational amplifier 115, and the current I C increases to I C_MAX = VOCP / R1, and the negative feedback loop is established.

[0133] During the third time period T3 (from time t3 to time t4), the negative feedback loop is maintained. The voltage VOCP at the first input terminal of the operational amplifier 115 is equal to the voltage VP at the second input terminal. The current I C of the power device 400 is maintained at I C_MAX , and the gate voltage VG of the power device 400 also remains unchanged.

[0134] The first time period T1, the second time period T2, and the third time period T3 are the preset delay times for soft turn-off. At time t4, the trigger signal generation circuit 113 generates a trigger signal SSD, and the linear current generation circuit 111 starts to output a soft turn-off control current I SS .

[0135] During the fourth time period T4 (from time t4 to time t5), the soft turn-off control current I SS gradually increases, the negative feedback loop is maintained, the voltage VOCP at the first input terminal of the operational amplifier 115 is equal to the voltage VP at the second input terminal, and the current I C of the power device 400 refers to Formula (3). Since the resistance value of the feedback resistor R2 is in the order of kilo-ohms and the sampling resistor R1 is in the order of milli-ohms, the resistance value of the feedback resistor R2 is much larger than that of the first sampling circuit R1. And the soft turn-off control current I SS generated by the linear current generation circuit 111 is small, and the current I C of the power device 400 is approximately:

[0136]

[0137] Therefore, as the soft turn-off control current I SS increases linearly, the current I C of the power device 400 decreases linearly, and the gate voltage VG of the power device 400 gradually decreases.

[0138] At time t5, the current I C of the power device 400 decreases to 0, the gate voltage VG of the power device 400 decreases to the threshold voltage, and the power device 400 turns off.

[0139] The fifth time period T5 (from time t5 to time t6), the gate voltage VG of the power device 400 continues to decrease. During the fifth time period T5, the current I of the power device 400 C is 0, and the negative feedback loop is disconnected. The voltage VP at the second input terminal of the operational amplifier 115 = I SS *(R1 + R2). The voltage VP at the second input terminal of the operational amplifier 115 gradually increases. The voltage VP at the second input terminal of the operational amplifier 115 is greater than the first reference voltage VOCP. The output of the operational amplifier 115 is high level, and the first switching transistor M1 is turned on. The gate voltage VG of the power device 400 is reduced to 0, achieving the turn-off of the power device 400 when the trigger condition is satisfied.

[0140] In some embodiments, as the soft turn-off control current I SS increases linearly, the current I of the power device 400 C decreases linearly, and the power device 400 is gradually turned off. The voltage V at the second terminal C of the power device 400 C gradually decreases. If the current Ic of the power device 400 rapidly drops to 0, a high voltage will be coupled out in the secondary side coil, causing misfiring. The embodiment of the present application avoids misfiring caused by the sudden turn-off of the power device 400 and the sudden change of the current I of the power device 400 C to 0 through soft turn-off, improving the reliability of the automotive ignition system.

[0141] The above are only the preferred embodiments of the present application and are not used to limit the present application. For those skilled in the art, various modifications and changes can be made to the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included within the protection scope of the present application.

Claims

1. A driving circuit, characterized in that, Comprising: A driving circuit input terminal, which receives an ignition signal. The ignition signal powers the internal unit of the driving circuit, and the ignition signal controls the first end of a power device. The first end of the power device is the control end of the power device.

2. The driving circuit according to claim 1, wherein: The internal unit of the driving circuit includes an operational amplifier; The driving circuit further includes a third resistor and a first capacitor. The first end of the third resistor is connected to the input terminal of the driving circuit and receives the ignition signal. The second end of the third resistor serves as a first voltage node. The first capacitor is connected between the second end of the third resistor and the ground. The first voltage node is connected to the operational amplifier, and the ignition signal powers the operational amplifier through the third resistor.

3. The driving circuit according to claim 1, wherein: The driving circuit further includes a sixth resistor. The first end of the sixth resistor is connected to the input terminal of the driving circuit, and the second end of the sixth resistor is connected to the first end of the power device. The ignition signal controls the conduction and cutoff of the power device through the sixth resistor.

4. The drive circuit according to claim 2, characterized in that, The internal unit of the driving circuit further includes a first voltage stabilizing circuit, which is connected between the first voltage node and the ground. The first voltage stabilizing circuit stabilizes the voltage of the first voltage node at a first target voltage.

5. The drive circuit according to claim 4, characterized in that, The first voltage stabilizing circuit includes: a seventh resistor, an eighth resistor, and an active clamping circuit. The active clamping circuit is connected between the first voltage node and the ground. The seventh resistor and the eighth resistor are connected in series between the first voltage node and the ground. The intermediate node of the seventh resistor and the eighth resistor is connected to the reference terminal of the active clamping circuit, and the voltage at the intermediate node of the seventh resistor and the eighth resistor is V REF , and the active clamping circuit stabilizes the voltage of the first voltage node N1 to: V REF is the voltage at the intermediate node of the seventh resistor and the eighth resistor, R7 is the resistance value of the seventh resistor, and R8 is the resistance value of the eighth resistor.

6. The drive circuit according to claim 2, characterized in that, The internal unit of the driving circuit further includes a second voltage stabilizing circuit, which is connected between the first end of the power device and the ground. When the ignition signal is at a high voltage, the second voltage stabilizing circuit stabilizes the voltage between the first end of the power device and the ground at a second target voltage to protect the first end of the power device. The second end of the power device is connected to an ignition coil. The ground terminal of the driving circuit is grounded, and the third end of the power device is grounded.

7. The drive circuit according to claim 6, wherein The second voltage stabilizing circuit is a Zener diode. The cathode of the Zener diode is connected to the first end of the power device, and the anode of the Zener diode D is grounded.

8. The drive circuit according to claim 2, wherein The driving circuit further includes a fourth resistor and a fifth resistor connected in series between the input terminal and the ground. The node between the fourth resistor and the fifth resistor is a second sampling node; The internal unit of the driving circuit further includes a protection circuit. The first input terminal of the protection circuit receives a temperature feedback signal. The second input terminal of the protection circuit is connected to the second sampling node and receives a voltage sampling signal. The output terminal of the protection circuit is connected to the second input terminal of the operational amplifier.

9. The drive circuit according to claim 8, wherein The protection circuit includes a trigger signal generation circuit and a linear current generation circuit. The first input terminal of the trigger signal generation circuit receives the temperature feedback signal. The second terminal of the trigger signal generation circuit is connected to the second sampling node and receives the voltage sampling signal. The input terminal of the linear current generation circuit is connected to the output terminal of the trigger signal generation circuit. The output terminal of the linear current generation circuit is connected to the second input terminal of the operational amplifier. When the trigger condition is satisfied, the trigger signal generation circuit generates a trigger signal, and the linear current generation circuit outputs a soft turn-off control current, and the soft turn-off control current increases linearly.

10. The drive circuit according to claim 9, characterized in that The trigger signal generation circuit includes a first comparator. The first input terminal of the first comparator is connected to a second reference voltage, and the second input terminal is connected to the second sampling node. When the voltage sampling signal at the second sampling node is greater than the second reference voltage, the trigger signal generation circuit generates the trigger signal.

11. The drive circuit according to claim 9, wherein, The trigger signal generation circuit includes a second comparator. Wherein, the first input terminal of the second comparator receives a third reference voltage, and the second input terminal is connected to a temperature-sensitive element. The temperature-sensitive element detects the temperature of the power device and generates the temperature feedback signal. When the temperature feedback signal provided by the temperature-sensitive element is less than the third reference voltage, the trigger signal generation circuit generates the trigger signal.

12. The drive circuit according to claim 2, wherein The drive circuit further includes: A first transistor, the second terminal and the third terminal of the first transistor are respectively connected to the first terminal of the power device and the ground; A first sampling circuit, the first terminal of the first sampling circuit is connected to the third terminal of the power device, and the second terminal of the first sampling circuit is grounded; The first input terminal of the operational amplifier receives a first reference voltage, the second input terminal of the operational amplifier is connected to the first terminal of the first sampling circuit, and the output terminal of the operational amplifier is connected to the first terminal of the first transistor.

13. The drive circuit according to claim 1, characterized in that The power device is an IGBT or an RC-IGBT. The first terminal of the power device is the gate, the second terminal of the power device is the collector, and the third terminal of the power device is the emitter; or the power device is a MOSFET. The first terminal of the power device is the gate, the second terminal of the power device is the drain, and the third terminal of the power device is the source.

14. The drive circuit according to claim 12, wherein The drive circuit further includes a feedback circuit. The feedback circuit is a feedback resistor, and the resistance value of the feedback resistor is in the order of kiloohms. The first sampling circuit is a first sampling resistor, and the resistance value of the first sampling resistor is in the order of milliohms.

15. The drive circuit according to claim 1, wherein The drive circuit and the power device are encapsulated in a packaging structure. The packaging structure includes: A packaging substrate, the first surface of the packaging substrate has a base island, and the drive circuit and the power device are located on the base island. Wherein, the drive circuit is isolated from the base island through an insulating layer.

16. The drive circuit according to claim 1, wherein, The drive circuit and the power device are encapsulated in a packaging structure. The packaging structure includes: An encapsulated substrate, on the first surface of which there are a first base island and a second base island isolated from each other. The drive circuit is located on the first base island, and the power device is located on the second base island.

17. The drive circuit according to claim 15 or 16, characterized in that, The input end of the drive circuit is connected to an input pin, the second end of the power device is connected to a collector pin, and the ground end of the drive circuit and the third end of the power device are connected to a ground pin.

18. The drive circuit according to claim 17, wherein The collector pin, the input pin and the ground pin are located on the same side of the encapsulation structure.

19. The drive circuit according to claim 17, wherein The encapsulation structure has and only has the collector pin, the input pin and the ground pin.

20. The drive circuit according to claim 15, characterized in that, The second end of the power device is mounted on the base island.

21. The drive circuit according to claim 16, characterized in that, The second end of the power device is mounted on the second base island.

22. The drive circuit according to claim 15 or 16, characterized in that, The encapsulation structure further includes: a temperature-sensitive element for detecting the temperature of the power device. The temperature-sensitive element and the power device are located on the same base island. The two ends of the temperature-sensitive element are electrically connected to the second end and the third end of the power device, and the two ends of the temperature-sensitive element are connected to the drive circuit and provide a temperature feedback signal to the drive circuit.

23. The drive circuit according to claim 17, characterized in that, The third end of the power device is electrically connected to the ground pin through a bonding wire, and the bonding wire is equivalent to the first sampling resistor.

24. The drive circuit according to claim 12, wherein, The first reference voltage and the first sampling circuit have a positive temperature coefficient.

25. The drive circuit according to claim 9, wherein The soft turn-off control current has a positive temperature coefficient.

26. The drive circuit according to claim 14, wherein The feedback resistor has a zero temperature coefficient.

27. The drive circuit according to claim 9, wherein When the triggering condition is satisfied, the triggering signal generating circuit delays for a predetermined time to output the triggering signal.

28. The drive circuit according to claim 1, wherein The ignition signal is provided to the input end of the drive circuit after being converted by the controller from the battery.

29. An automotive ignition system, characterized in that, Including: A controller; An ignition coil; A battery, which outputs an electrical signal and supplies power to the ignition coil and the controller. The controller receives the electrical signal and converts it into an ignition signal; A power device; the second end of the power device is connected to the ignition coil, and the third end of the power device is grounded; and The drive circuit according to any one of claims 1 to 28.

30. The ignition system according to claim 29, wherein, The drive circuit is not directly connected to the battery.

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