Driving system and driving method of vehicle-mounted lamp and vehicle

Abstract

The invention provides a driving system and method for a vehicle-mounted lamp and a vehicle, and relates to the technical field of vehicle lamps, and the driving system comprises a single-end primary inductance converter and a control module; the single-end primary inductance converter comprises a power supply module and a gallium nitride switch module, and the gallium nitride switch module is connected with the power supply module and the vehicle-mounted lamp; the control module is connected with the gallium nitride switch module and the vehicle-mounted lamp, the control module is used for detecting the load current of the vehicle-mounted lamp and switching the on-off state of the gallium nitride switch module and the working mode of the driving system based on the load current, and the working mode comprises a pulse width modulation mode, a pulse frequency modulation mode and a burst mode. The system is provided with the gallium nitride switch module, so that the synchronous rectification effect can be achieved, and the conduction loss and the switching loss are relatively low. And secondly, the system adopts a hybrid modulation strategy, so that the optimal working mode can be automatically switched in different load states, and the driving stability, reliability and efficiency of the system are improved.

Description

Technical Field

[0001] The present application relates to the technical field of vehicle lamps, and more particularly, to a driving system and a driving method for a vehicle-mounted lamp and a vehicle. Background Art

[0002] Vehicles are typically equipped with a single-ended primary inductor converter (SEPIC) to drive light-emitting diodes (LEDs), electric motors, and other components. Specifically, SEPICs can adjust the brightness of LEDs in vehicle lamps using pulse-width modulation (PWM) signals to meet varying lighting requirements.

[0003] Currently, SEPICs in related technologies are typically equipped with rectifier diodes and metal oxide semiconductor (MOS) switches. However, the rectification losses of the rectifier diodes and the switching losses of the MOS switches are large, resulting in low overall driving stability and efficiency of the SEPIC. Summary of the Invention

[0004] To solve the above problems, the present application provides a driving system, driving method and vehicle for a vehicle-mounted lamp, aiming to solve the problem in the related art that when SEPIC uses a rectifier diode and a MOS switch tube, the rectification loss of the rectifier diode and the switching loss of the MOS switch tube are large, resulting in low overall driving stability and efficiency of the SEPIC.

[0005] In a first aspect, the present application provides a driving system for an on-board lamp, comprising a single-ended primary inductor converter and a control module; the single-ended primary inductor converter comprises a power module and a gallium nitride switch module, the gallium nitride switch module being connected to the power module and the on-board lamp; the control module being connected to the gallium nitride switch module and the on-board lamp, the control module being used to detect the load current of the on-board lamp and switch the on-off state of the gallium nitride switch module and the operating mode of the driving system based on the load current, the operating modes comprising pulse width modulation mode, pulse frequency modulation mode and burst mode.

[0006] In the above technical solution, when the control module determines based on the load current that the on-board lamp is in a heavy-load state, the drive system operates in PWM mode so that the gallium nitride switch module can output a stable output voltage to the on-board lamp. When the control module determines based on the load current that the on-board lamp is in a medium-load state, the drive system can continue to operate in PWM mode, and the control module can appropriately adjust the duty cycle of the output PWM signal to optimize efficiency. When the control module determines based on the load current that the on-board lamp is in a light-load state, the drive system operates in PFM mode, thereby reducing the switching frequency of the gallium nitride switch module to reduce losses. When the control module determines based on the load current that the on-board lamp is in an extremely light-load or no-load state, the drive system 1 operates in Burst mode, at which time the drive system operates intermittently to maintain a standby state and reduce energy consumption. Specifically, the drive system employs a hybrid modulation strategy, employing multiple modulation modes (PWM, PFM, and Burst) to adapt to operating conditions across different load ranges (i.e., from no-load to heavy-load). This allows the drive system to automatically switch to the optimal control mode under different load conditions, maintaining high efficiency under heavy, medium, light, and no-load conditions. This improves the drive system's driving stability, reliability, and efficiency. Furthermore, the drive system dynamically selects the most appropriate modulation method based on the load state of the vehicle lamp, reducing unnecessary switching and static losses. Furthermore, the drive system of this application incorporates a gallium nitride (GaN) switch module. The GaN devices in this GaN switch module have extremely low on-resistance and fast switching speeds, enabling them to replace diodes in related art for synchronous rectification, avoiding the rectification losses associated with diode rectification. Furthermore, compared to MOS switches, GaN switch modules have lower conduction and switching losses, reducing switching losses and further improving the drive system's driving stability and efficiency. The high-frequency switching noise generated by the GaN switch module when operating at high frequencies is much lower than that of the MOS switch tube, and can meet the industry's high-frequency switching noise testing and requirement standards for automotive electronic equipment.

[0007] In combination with the first aspect, in some possible implementations, when the load current is greater than or equal to a first threshold current, the drive system operates in a pulse width modulation mode; when the load current is less than the first threshold current, the drive system operates in a pulse frequency modulation mode; when the load current is less than a second threshold current, the drive system operates in a burst mode; wherein the second threshold current is less than the first threshold current.

[0008] In this technical solution, the control module presets a first threshold current and a second threshold current. The control module compares the detected load current with these first and second threshold currents to accurately determine the load status of the vehicle lamp and switches the operating state of the drive system accordingly, enabling the drive system to automatically switch to the optimal control mode under different load conditions. This achieves high-efficiency drive under heavy, medium, light, and no-load conditions, improving the drive system's driving stability, reliability, and efficiency.

[0009] In combination with the first aspect and the above-mentioned implementations, in some possible implementations, the GaN switch module includes a first GaN high electron mobility transistor and a second GaN high electron mobility transistor; the drain of the first GaN high electron mobility transistor is connected to the vehicle lamp, and the gate of the first GaN high electron mobility transistor is connected to the control module; the source of the second GaN high electron mobility transistor is connected to the vehicle lamp and the power module, the gate of the second GaN high electron mobility transistor is connected to the control module, and the drain of the second GaN high electron mobility transistor, the source of the first GaN high electron mobility transistor, and the power module are interconnected to form a common node; wherein the control module is used to send a high-side control signal to the gate of the first GaN high electron mobility transistor, and send a control signal to the gate of the second GaN high electron mobility transistor.

[0010] In the above technical solution, the control module can change the on-off state of the first GaN high-electron-mobility transistor and the second GaN high-electron-mobility transistor accordingly through the high-side control signal and the low-side control signal. At the same time, by adjusting the duty cycle of the high-side control signal and the low-side control signal, the on-off time of the first GaN high-electron-mobility transistor and the second GaN high-electron-mobility transistor can be adjusted accordingly to adjust the brightness of the vehicle lamps, with high adjustment flexibility and reliability. Secondly, the switching speed of the first GaN high-electron-mobility transistor and the second GaN high-electron-mobility transistor is relatively fast, which is suitable for high-frequency switching applications such as SEPIC, with low switching losses and high conversion efficiency. The on-resistance of the first GaN high-electron-mobility transistor and the second GaN high-electron-mobility transistor is also low, which can reduce power loss in the on state and improve the overall efficiency of the GaN switch module.

[0011] In combination with the first aspect and the above-mentioned implementation manner, in some possible implementation manners, the power supply module includes a power supply and an inductor; the negative electrode of the power supply is connected to the source electrode of the second gallium nitride high electron mobility transistor; one end of the inductor is connected to the positive electrode of the power supply, and the other end of the inductor is connected to the common node.

[0012] In the above technical solution, the power supply provides the input voltage required by the drive system, and the inductor stabilizes the current during the on / off phases of the first and second GaN HEMTs. Specifically, when the GaN switch module is in the on phase, the first GaN HEMT is on and the second GaN HEMT is off. At this point, current flows from the power supply through the inductor, causing the inductor to begin storing energy and gradually increase in current. When the GaN switch module is in the off phase, the first GaN HEMT is off and the second GaN HEMT is on. The current in the inductor does not disappear instantly; it continues to flow through the second GaN HEMT, releasing the stored energy. In other words, the second GaN HEMT provides a low-impedance discharge path for the inductor, causing the inductor current to gradually decrease. In this way, by controlling the on / off phases of the first and second GaN HEMTs, the average current in the inductor can be adjusted accordingly, thereby controlling the brightness of the vehicle lighting, providing high adjustment flexibility.

[0013] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the driving system also includes a filtering module, one end of the filtering module is connected to the drain of the first gallium nitride high electron mobility transistor and the vehicle-mounted lamp, and the other end of the filtering module is connected to the source of the second gallium nitride high electron mobility transistor and the vehicle-mounted lamp.

[0014] In the above technical solution, the filtering module is used to smooth the output voltage of the first GaN high electron mobility transistor and the second GaN high electron mobility transistor, providing a more stable output voltage to the vehicle lamp to ensure the reliability of the vehicle lamp's light emission based on the output voltage.

[0015] In combination with the first aspect and the above implementations, in some possible implementations, the first GaN high electron mobility transistor and the second GaN high electron mobility transistor operate in a zero voltage switching mode.

[0016] In the above technical solution, the first and second GaN HEMTs operate in zero-voltage switching mode, significantly reducing switching losses and thus improving the overall output efficiency of the power module. Furthermore, ZVS technology reduces the voltage across the first and second GaN HEMTs to zero before they are turned on, thereby reducing losses during the switching process. This further reduces energy losses when the first and second GaN HEMTs operate at high frequencies, improving the overall performance of the drive system. Furthermore, ZVS technology not only reduces switching losses in the first and second GaN HEMTs, but also reduces electromagnetic interference and helps reduce high-frequency noise, enabling the first and second GaN HEMTs to meet industry standards for high-frequency switching noise in automotive electronic devices.

[0017] In combination with the first aspect and the above-mentioned implementation methods, in some possible implementation methods, the drive system also includes a temperature compensation module, which is connected to the gallium nitride switch module and the control module. The temperature compensation module is used to detect the junction temperature of the gallium nitride switch module and send it to the control module. The control module is used to adjust the output current of the gallium nitride switch module based on the junction temperature.

[0018] In the above technical solution, the temperature compensation module can monitor the GaN junction temperature in the GaN switch module in real time to provide temperature feedback to the drive system. When the junction temperature received by the control module is too high, the control module can automatically reduce the output power or current of the drive system 1, thereby reducing the power consumption of the GaN switch module, lowering its temperature and preventing overheating. In other words, the control module can adjust the output current of the GaN switch module based on the junction temperature to prevent overheating, extend the service life and reliability of the GaN switch module, and thus improve the driving reliability of the drive system.

[0019] In a second aspect, an embodiment of the present application provides a method for driving a vehicle lamp, which is applied to the driving system described in any optional embodiment of the first aspect, and the method includes: Get the load current of the vehicle lamp; The on-off state of the GaN switch module and the operating mode of the drive system are switched based on the load current. The operating modes include pulse width modulation mode, pulse frequency modulation mode and burst mode.

[0020] The aforementioned technical solution utilizes a hybrid modulation strategy, employing multiple modulation modes (PWM, PFM, and Burst) to adapt to operating conditions across different load ranges (from no-load to heavy-load). This allows the drive system to automatically switch to the optimal control mode under varying load conditions, maintaining high efficiency under heavy, medium, light, and no-load conditions. This improves the drive system's stability, reliability, and efficiency. Furthermore, the drive system dynamically selects the most appropriate modulation mode based on the vehicle lamp's load state, reducing unnecessary switching and static losses.

[0021] In conjunction with the second aspect, in some possible implementations, the on-off state of the gallium nitride switch module and the operating mode of the drive system are switched based on the load current. The operating modes include pulse width modulation mode, pulse frequency modulation mode, and burst mode, including: When the load current is greater than or equal to a first threshold current, the drive system operates in a pulse width modulation mode; When the load current is less than the first threshold current, the drive system operates in a pulse frequency modulation mode; When the load current is less than the second threshold current, the drive system operates in a burst mode, and the second threshold current is less than the first threshold current.

[0022] In the above technical solution, the driving method presets a first threshold current and a second threshold current. The control module compares the detected load current with the first threshold current and the second threshold current to accurately know the load state of the vehicle lamp and switches the working state of the driving system accordingly, so that the driving system can automatically switch to the optimal control mode under different load states. This achieves high-efficiency driving under heavy load, medium load, light load and no-load conditions, and improves the driving stability, driving reliability and efficiency of the driving method. In a third aspect, an embodiment of the present application provides a vehicle, comprising a vehicle-mounted lamp and a drive system as described in any optional manner of the first aspect, wherein the drive system is connected to the vehicle-mounted lamp. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a schematic diagram of the module structure of a drive system provided in an embodiment of the present application; Figure 2 This is a schematic diagram of the module structure of another drive system provided in an embodiment of the present application; Figure 3 This is a schematic diagram of the circuit structure of a drive system provided in an embodiment of the present application; Figure 4 is a schematic diagram of the circuit structure of another drive system provided in an embodiment of the present application; Figure 5 This is a schematic diagram of the circuit structure of another drive system provided in an embodiment of the present application; Figure 6 This is a flow chart of a driving method provided in an embodiment of the present application.

[0024] Wherein, the reference numerals: 1. Drive system; 11. Single-ended primary inductor converter; 111. Power module; 112. GaN switch module; 12. Control module; 13. Filter module; 2. Vehicle lighting; GaN1, first gallium nitride high electron mobility transistor; GaN2, second gallium nitride high electron mobility transistor; SW, common node; V, power supply; L, inductor; ILED, load current. DETAILED DESCRIPTION

[0025] The following will clearly and thoroughly describe the technical solutions in this application in conjunction with the accompanying drawings. In the description of the embodiments of this application, unless otherwise specified, " / " means or, for example, A / B can mean A or B: "and / or" in the text is only a description of the association relationship of associated objects, indicating that there can be three relationships, for example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. In addition, in the description of the embodiments of this application, "multiple" means two or more than two.

[0026] In the following, the terms "first" and "second" are used for descriptive purposes only and should not be understood to imply or suggest relative importance or implicitly indicate the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features.

[0027] Currently, a SEPIC is commonly used in vehicle electronic systems to drive loads (such as LEDs and electric motors). For example, in a vehicle's headlight system, the SEPIC can adjust the brightness of the LEDs and provide a stable power supply. A SEPIC in related art consists of a control chip, a diode, and a MOS switch. The diode is used for rectification and freewheeling, while the control chip outputs a PWM signal. This PWM signal adjusts the operating frequency and duty cycle of the MOS switch, thereby varying the output voltage and, therefore, adjusting the brightness of the LEDs in the vehicle's lighting fixtures to suit different lighting needs.

[0028] However, when the rectifier diode is in the on-state, its internal resistance generates a certain amount of power dissipation. During the switching process, the rectifier diode also generates energy losses due to transient changes in current and voltage. When the MOS switch is in the on-state, due to its on-resistance, current flowing through it generates heat, which in turn leads to losses. The MOS switch in the SEPIC requires frequent on- and off-state cycling. When the MOS switch switches from the on-state to the off-state (or vice versa), the voltage and current cannot switch instantaneously, resulting in a brief overlap and additional losses. Consequently, the significant rectification losses of the rectifier diode and the switching losses of the MOS switch affect the overall efficiency of the SEPIC, resulting in lower driving stability and efficiency, especially at low loads. For example, the rectification losses of the rectifier diode and the switching losses of the MOS switch result in low efficiency across the full load range (typically 70-88%). At light loads, the efficiency plummets to below 50%, compromising the proper operation of the SEPIC. Secondly, MOS switches need to switch on and off frequently, which means that they operate at high frequencies. When operating at high frequencies, MOS switches generate high-frequency switching noise, making it difficult to meet the industry's high-frequency switching noise testing and requirements for automotive electronic equipment (such as CISPR 25 Class 5).

[0029] To this end, embodiments of the present application provide a driving system, driving method, and vehicle for a vehicle-mounted lamp. The driving system incorporates a gallium nitride switch module, enabling synchronous rectification with low conduction and switching losses. Furthermore, the system employs a hybrid modulation strategy, automatically switching to the optimal operating mode under varying load conditions to improve driving stability, reliability, and efficiency.

[0030] The following is an exemplary introduction to the driving system, driving method and vehicle of the vehicle-mounted lamp provided in the present application with reference to the accompanying drawings.

[0031] In one example, if Figure 1 As shown, the present application provides a vehicle, including a drive system 1 and a vehicle-mounted lamp 2. The drive system 1 is connected to the vehicle-mounted lamp 2. The vehicle-mounted lamp 2 is provided with an LED array. The drive system 1 can adjust the brightness of the LED array in the vehicle lamp 2 to adapt to different lighting needs.

[0032] In order to enable the driving system 1 provided by the present application to adjust the brightness of the LED array in the vehicle lamp 2, in one example, Figure 2As shown, the driving system 1 of the vehicle lamp 2 includes a single-ended primary inductor converter 11 and a control module 12. The single-ended primary inductor converter 11 is connected to the control module 12 and the vehicle lamp 2. The control module 12 is used to change the frequency of the single-ended primary inductor converter 11 to change the actual voltage / current value output to the vehicle lamp 2, thereby achieving the purpose of adjusting the brightness of the LED array in the vehicle lamp 2.

[0033] Optional, such as Figure 2 As shown, the single-ended primary inductor converter 11 includes a power module 111 and a gallium nitride (GaN) switch module 112 . The GaN switch module 112 is connected to the power module 111 and the vehicle lamp 2 . The control module 12 is connected to the GaN switch module 112 and the vehicle lamp 2 .

[0034] Among them, the control module 12 is used to detect the load current ILED of the vehicle-mounted lamp 2. It is worth noting that the load current ILED refers to the current value actually passing through the lamp when the vehicle-mounted lamp 2 is working. This value will change with the size of the load of the vehicle-mounted lamp 2. When the load current ILED is small, the vehicle-mounted lamp 2 is in a light load state. When the load current ILED is large, the vehicle-mounted lamp 2 is in a heavy load state. This means that the control module 12 can determine the current working state of the vehicle-mounted lamp 2 based on the detected load current ILED. For example, when the detected load current ILED is small, it is determined that the vehicle-mounted lamp 2 is working in a light load state at this time; when the detected load current ILED is large, it is determined that the vehicle-mounted lamp 2 is working in a heavy load state at this time.

[0035] After the control module 12 determines the current operating state of the vehicle lamp 2 based on the load current ILED, it also switches the on / off state of the GaN switch module 112 based on the detected load current ILED to change the dead time of the GaN switch module 112 and optimize the dead time, thereby ensuring that the drive system 1 maintains high efficiency and stability across the entire load range (i.e., light and heavy load states). It is worth noting that by dynamically adjusting the on / off state of the GaN switch module 112, the output voltage of the GaN switch module 112 to the vehicle lamp 2 can be correspondingly changed, thereby adjusting the brightness of the vehicle lamp 2. In other words, the control module 12 can dynamically adjust the dead time in real time based on the load current ILED. This dead time can be extended under light load conditions to prevent body diode conduction, and shortened under heavy load conditions to improve efficiency.

[0036] The control module 12 provided in the present application will also switch the working mode of the driving system 1 based on the detected load current ILED to adapt to different load conditions.

[0037] Exemplarily, the operating modes include a pulse width modulation (PWM) mode, a pulse frequency modulation (PFM) mode, and a burst mode.

[0038] PWM mode is a technique for controlling output voltage or power by adjusting the duty cycle of a pulse signal. It is understood that within each cycle, the GaN switch module 112 is on for a period of time (during which the output of the control module 12 is a high level) and off for another period of time (during which the output of the control module 12 is a low level). By varying the duty cycle (i.e., the on-time) of the PWM signal output by the control module 12, the output voltage or power of the GaN switch module 112 can be varied, thereby adjusting the brightness of the LED array in the vehicle lamp 2. Specifically, at a fixed frequency, by varying the duration of the high level output to the GaN switch module 112, the on-time of the GaN switch module 112 is adjusted, thereby varying the output of the GaN switch module 112 and, consequently, adjusting the brightness of the LED array in the vehicle lamp 2. The PWM mode can achieve stable output voltage regulation under medium and high load conditions. To this end, when the control module 12 determines that the vehicle lamp 2 is in a medium and high load state based on the detected load current ILED, the control module 12 switches the working mode of the drive system 1 to the PWM mode, so that the drive system 1 can achieve stable output voltage regulation under medium and high load conditions to ensure regulation efficiency and reliability.

[0039] PFM mode is a technology that controls output power by adjusting the switching frequency. It should be understood that within each cycle, the on-time of the GaN switch module 112 remains constant (i.e., the pulse width remains constant), but the length of the entire cycle (frequency) varies. A higher frequency results in a greater number of on-times per unit time; a lower frequency results in a smaller number of on-times per unit time. In other words, under a fixed pulse width, the on-off cycle of the GaN switch module 112 is controlled by adjusting the switching frequency. PFM mode is typically suitable for light load conditions. Therefore, when the control module 12 determines that the vehicle lamp 2 is in a light load state based on the detected load current ILED, the control module 12 switches the operating mode of the drive system 1 to PFM mode. When the drive system 1 operates in PFM mode, the switching frequency of the GaN switch module 112 is reduced, thereby reducing switching losses and improving drive efficiency. This avoids unnecessary energy loss caused by the fixed PWM frequency under light load conditions.

[0040] Burst mode is an energy-saving mode used under extremely light load or no-load conditions. In burst mode, the control module 12 keeps the GaN switch module 112 off for extended periods, occasionally turning it on for short periods to maintain a stable output voltage. Specifically, the GaN switch module 112 is completely off for a period of time (no switching losses), then turned on again for several short periods of time to replenish energy. This periodic "sleep-wake" mechanism in burst mode significantly reduces static power consumption.

[0041] In this way, when the control module 12 determines that the vehicle lamp 2 is under heavy load based on the load current ILED, the drive system 1 operates in PWM mode, allowing the GaN switch module 112 to output a stable output voltage to the vehicle lamp 2. When the control module 12 determines that the vehicle lamp 2 is under medium load based on the load current ILED, the drive system 1 can continue to operate in PWM mode, and the control module 12 can appropriately adjust the duty cycle of the output PWM signal to optimize efficiency. When the control module 12 determines that the vehicle lamp 2 is under light load based on the load current ILED, the drive system 1 operates in PFM mode, thereby reducing the switching frequency of the GaN switch module 112 to reduce losses. When the control module 12 determines that the vehicle lamp 2 is under very light load or no load based on the load current ILED, the drive system 1 operates in Burst mode, in which the drive system 1 operates intermittently to maintain a standby state and reduce energy consumption.

[0042] In summary, the drive system 1 of the present application adopts a hybrid modulation strategy, namely, using multiple modulation modes (PWM mode, PFM mode, and Burst mode) to adapt to operating conditions within different load ranges (i.e., from no-load to heavy-load). This allows the drive system 1 to automatically switch to the optimal control mode under different load conditions, maintaining high efficiency under heavy, medium, light, and no-load conditions, thereby improving the driving stability, reliability, and efficiency of the drive system 1. Furthermore, the drive system 1 can dynamically select the most appropriate modulation mode based on the load state of the vehicle lamp 2, reducing unnecessary switching losses and static losses. Furthermore, the drive system 1 of the present application is equipped with a gallium nitride switch module 112. The gallium nitride devices in the gallium nitride switch module 112 have extremely low on-resistance and fast switching speed. They can replace the diodes used in related art to perform synchronous rectification, avoiding the rectification losses associated with diode rectification. Furthermore, compared to MOS switches, the gallium nitride switch module 112 has lower conduction and switching losses, reducing the switching losses of the switch, thereby further improving the driving stability and efficiency of the drive system 1. The high-frequency switching noise generated by the GaN switch module 112 when operating at high frequency is much lower than that of the MOS switch tube, and can meet the testing and requirement standards for high-frequency switching noise of vehicle-mounted electronic equipment in the industry.

[0043] To accurately detect the load state and accurately switch the operating mode of the drive system 1, in one example, when the load current ILED is greater than or equal to a first threshold current, the drive system 1 operates in a pulse width modulation mode; when the load current ILED is less than the first threshold current, the drive system 1 operates in a pulse frequency modulation mode; and when the load current ILED is less than a second threshold current, the drive system 1 operates in a burst mode. The second threshold current is less than the first threshold current.

[0044] In this example, the control module 12 is configured with a first threshold current and a second threshold current. For example, assume the first threshold current is 0.5A and the second threshold current is 0.1A. When the load current ILED detected by the control module 12 is greater than or equal to 0.5A, the vehicle lamp 2 is under heavy load, causing the drive system 1 to operate in PWM mode. In this case, the control module 12 controls the GaN switch module 112 to operate at a fixed frequency, such as 500kHz. In PWM mode, the GaN switch module 112 can output a stable output voltage to the vehicle lamp 2. When the load current ILED detected by the control module 12 is less than 0.5A, the vehicle lamp 2 is under light load, causing the drive system 1 to operate in PFM mode. In this case, the control module 12 controls the GaN switch module 112 to operate in pulse frequency modulation (PFM) mode, such as 100kHz-500kHz, thereby reducing the switching frequency of the GaN switch module 112 to minimize losses. When the load current ILED detected by the control module 12 is less than 0.1A, the vehicle lamp 2 is in an unloaded state, causing the drive system 1 to operate in Burst mode. The control module 12 then controls the gallium nitride switch module 112 to sleep in the next cycle to reduce static power consumption. The specific current values ​​of the first and second threshold currents can be set according to actual needs and are not specifically limited in this application.

[0045] In this way, the control module 12 is preset with a first threshold current and a second threshold current. The control module 12 compares the detected load current ILED with the first and second threshold currents to accurately determine the load state of the vehicle lamp 2 and switches the operating state of the drive system 1 accordingly, allowing the drive system 1 to automatically switch to the optimal control mode under different load conditions. This achieves high-efficiency driving under heavy, medium, light, and no-load conditions, improving the driving stability, reliability, and efficiency of the drive system 1.

[0046] In one example, if Figure 3As shown, the GaN switch module 112 includes a first GaN high electron mobility transistor (GaN HEMT) GaN1 and a second GaN HEMT GaN2. The drain of the first GaN HEMT GaN1 is connected to the vehicle lamp 2, and the gate of the first GaN HEMT GaN1 is connected to the control module 12. The source of the second GaN HEMT GaN2 is connected to the vehicle lamp 2 and the power module 111, and the gate of the second GaN HEMT GaN2 is connected to the control module 12. The drain of the second GaN HEMT GaN2, the source of the first GaN HEMT GaN1, and the power module 111 are interconnected to form a common node SW.

[0047] The control module 12 is configured to send a high-side control signal HS_IN to the gate of the first GaN-HEMT GaN1 and a control signal LS_IN to the gate of the second GaN-HEMT GaN2. This means that the first GaN-HEMT GaN1 functions as a high-side switch, while the second GaN-HEMT GaN2 functions as a low-side switch. The first and second GaN-HEMTs GaN1 and GaN2 are not turned on simultaneously, but instead operate alternately, forming a so-called "half-bridge" structure.

[0048] For example, when the GaN switch module 112 is in the on-state, the control module 12 controls the first GaN high-electron-mobility transistor (HEMT) GaN1 via the high-side control signal HS_IN, causing the current to gradually increase. Simultaneously, the control module 12 controls the second GaN high-electron-mobility transistor (HEMT) GaN2 via the low-side control signal LS_IN, preventing the current from flowing directly to ground. When the GaN switch module 112 is in the off-state, the control module 12 controls the first GaN high-electron-mobility transistor (HEMT) GaN1 via the high-side control signal HS_IN, while controlling the second GaN high-electron-mobility transistor (HEMT) GaN2 via the low-side control signal LS_IN. It is worth noting that by varying the on-time ratio (i.e., duty cycle) of the high-side control signal HS_IN and the low-side control signal LS_IN, the control module 12 can adjust the average current in the power module 111, thereby controlling the brightness of the vehicle lamp 2. For example, when the duty cycle is high, the on-time of the high-side control signal HS_IN is long, the power module 111 stores more energy, the average current is large, and the brightness of the vehicle lamp 2 is high. When the duty cycle is low, the on-time of the high-side control signal HS_IN is short, the power module 111 stores less energy, the average current is small, and the brightness of the vehicle lamp 2 is low.

[0049] In this example, the control module 12 can change the on / off states of the first GaN-HEMT GaN1 and the second GaN-HEMT GaN2 via the high-side control signal HS_IN and the low-side control signal LS_IN. Simultaneously, by adjusting the duty cycle of the high-side control signal HS_IN and the low-side control signal LS_IN, the on / off time of the first GaN-HEMT GaN1 and the second GaN-HEMT GaN2 can be adjusted accordingly, thereby adjusting the brightness of the vehicle lamp 2. This provides high adjustment flexibility and reliability. Furthermore, the first GaN-HEMT GaN1 and the second GaN-HEMT GaN2 have fast switching speeds, making them suitable for high-frequency switching applications such as SEPIC, with low switching losses and high conversion efficiency. The first GaN-HEMT GaN1 and the second GaN-HEMT GaN2 also have low on-resistance, which reduces power loss in the on-state and improves the overall efficiency of the GaN switch module 112.

[0050] In one example, if Figure 4 As shown, the power module 111 includes a power supply V and an inductor L. The negative electrode of the power supply V is connected to the source of the second GaN high electron mobility transistor GaN2, one end of the inductor L is connected to the positive electrode of the power supply V, and the other end of the inductor L is connected to the common node SW.

[0051] In this example, power supply V provides the input voltage required by drive system 1, and inductor L stabilizes the current during the on / off phases of the first GaN HEMT GaN1 and the second GaN HEMT GaN2. Specifically, when GaN switch module 112 is in the on phase, the first GaN HEMT GaN1 is on and the second GaN HEMT GaN2 is off. At this point, current flows from power supply V through inductor L, causing inductor L to begin storing energy and gradually increase in current. When GaN switch module 112 is in the off phase, the first GaN HEMT GaN1 is off and the second GaN HEMT GaN2 is on. The current in inductor L does not disappear instantly; instead, it continues to flow through the second GaN HEMT GaN2, releasing the stored energy. In other words, the second GaN HEMT GaN2 provides a low-impedance discharge path for inductor L, causing the current in inductor L to gradually decrease. In this way, by controlling the on and off states of the first GaN high electron mobility transistor GaN1 and the second GaN high electron mobility transistor GaN2, the average current in the inductor L can be adjusted accordingly, thereby controlling the brightness of the vehicle lamp 2 with high adjustment flexibility.

[0052] In one example, if Figure 5As shown, the driving system 1 further comprises a filter module 13, one end of the filter module 13 is connected with the drain of the first GaN high electron mobility transistor GAN1 and the vehicle-mounted lamp 2, and the other end of the filter module 13 is connected with the source of the second GaN high electron mobility transistor GAN2 and the vehicle-mounted lamp 2.

[0053] In this example, the filter module 13 is used to smooth the output voltage of the first GaN high electron mobility transistor GAN1 and the second GaN high electron mobility transistor GAN2, and provide a more stable output voltage to the vehicle-mounted lamp 2, so as to ensure the reliability of the vehicle-mounted lamp 2 based on the output voltage.

[0054] Optionally, the filter module 13 can adopt a filter capacitor, or an RC filter composed of a filter capacitor and a resistor, which can be set according to actual needs, and the present application does not make specific limitations.

[0055] In one example, the first GaN high electron mobility transistor GAN1 and the second GaN high electron mobility transistor GAN2 work in a zero voltage switching (ZVS) mode.

[0056] In this example, the first GaN high electron mobility transistor GAN1 and the second GaN high electron mobility transistor GAN2 working in the zero voltage switching mode can significantly reduce the switching loss, thereby improving the overall output efficiency of the power module 111. And through the ZVS technology, the voltage between the first GaN high electron mobility transistor GAN1 and the second GaN high electron mobility transistor GAN2 is reduced to zero before the first GaN high electron mobility transistor GAN1 and the second GaN high electron mobility transistor GAN2 are turned on, thereby reducing the loss in the switching process. This makes the first GaN high electron mobility transistor GAN1 and the second GaN high electron mobility transistor GAN2 run at a high frequency, which can further reduce energy loss and improve the overall performance of the driving system 1. Secondly, the ZVS technology not only reduces the switching loss of the first GaN high electron mobility transistor GAN1 and the second GaN high electron mobility transistor GAN2, but also reduces the electromagnetic interference (EMI), which helps to reduce high-frequency noise, so that the first GaN high electron mobility transistor GAN1 and the second GaN high electron mobility transistor GAN2 can meet the test and requirement standards of high-frequency switching noise of the vehicle-mounted electronic equipment in the industry.

[0057] In one example, the drive system 1 further includes a temperature compensation module (not shown), which is connected to the GaN switch module 112 and the control module 12. The temperature compensation module is configured to detect the junction temperature of the GaN switch module 112 and transmit the detected temperature to the control module 12. The control module 12 is configured to adjust the output current of the GaN switch module 112 based on the junction temperature.

[0058] In this example, the temperature compensation module can monitor the GaN junction temperature in the GaN switch module 112 in real time to provide temperature feedback for the drive system 1. When the junction temperature received by the control module 12 is too high, the control module 12 can automatically reduce the output power or current of the drive system 1, thereby reducing the power consumption of the GaN switch module 112, lowering its temperature and preventing overheating. In other words, the control module 12 can adjust the output current of the GaN switch module 112 based on the junction temperature to prevent the GaN switch module 112 from overheating, thereby increasing the service life and reliability of the GaN switch module 112, and thus improving the driving reliability of the drive system 1.

[0059] Optionally, the temperature compensation module can utilize a negative temperature coefficient (NTC). The resistance of a thermistor decreases as the temperature increases. When a thermistor is used in the temperature compensation module, its resistance decreases as the junction temperature of the GaN switch module 112 increases. The thermistor outputs an analog signal indicating this change to the control module 12. Based on this analog signal, the control module 12 can determine the junction temperature of the GaN switch module 112. Based on this junction temperature, the control module 12 then adjusts the output current (e.g., the drive current of the vehicle lamp 2), reduces the PWM duty cycle, limits the output power, and so on, to reduce the power consumption of the GaN switch module 112 and lower its temperature.

[0060] In summary, the drive system 1 of the present application adopts a hybrid modulation strategy, namely, using multiple modulation modes (PWM mode, PFM mode, and Burst mode) to adapt to operating conditions within different load ranges (i.e., from no-load to heavy-load). This allows the drive system 1 to automatically switch to the optimal control mode under different load conditions, maintaining high efficiency under heavy, medium, light, and no-load conditions, thereby improving the driving stability, reliability, and efficiency of the drive system 1. Furthermore, the drive system 1 can dynamically select the most appropriate modulation mode based on the load state of the vehicle lamp 2, reducing unnecessary switching losses and static losses. Furthermore, the drive system 1 of the present application is equipped with a gallium nitride switch module 112. The gallium nitride devices in the gallium nitride switch module 112 have extremely low on-resistance and fast switching speed. They can replace the diodes used in related art to perform synchronous rectification, avoiding the rectification losses associated with diode rectification. Furthermore, compared to MOS switches, the gallium nitride switch module 112 has lower conduction and switching losses, reducing the switching losses of the switch, thereby further improving the driving stability and efficiency of the drive system 1. The high-frequency switching noise generated by the GaN switch module 112 when operating at high frequency is much lower than that of the MOS switch tube, and can meet the testing and requirement standards for high-frequency switching noise of vehicle-mounted electronic equipment in the industry.

[0061] In one example, Figure 6 1 is a schematic flow chart of a method for driving a vehicle lamp provided in an embodiment of the present application; the method 100 includes S101 to S102; S101 to S102 are described in detail below.

[0062] The driving method is applied to the above-mentioned driving system 1, and the driving system 1 may refer to Figures 1 to 5 The multi-motor control system 1 shown in FIG. For example, the drive system 1 includes a single-ended primary inductor converter 11 and a control module 12. The single-ended primary inductor converter 11 is connected to the control module 12 and the vehicle lamp 2. Furthermore, the single-ended primary inductor converter 11 includes a power module 111 and a gallium nitride switch module 112.

[0063] S101. Obtain the load current of the vehicle-mounted lamp.

[0064] Among them, the control module 12 is used to detect the load current ILED of the vehicle-mounted lamp 2. It is worth noting that the load current ILED refers to the current value actually passing through the lamp when the vehicle-mounted lamp 2 is working. This value will change with the size of the load of the vehicle-mounted lamp 2. When the load current ILED is small, the vehicle-mounted lamp 2 is in a light load state. When the load current ILED is large, the vehicle-mounted lamp 2 is in a heavy load state. This means that the control module 12 can determine the current working state of the vehicle-mounted lamp 2 based on the detected load current ILED. For example, when the detected load current ILED is small, it is determined that the vehicle-mounted lamp 2 is working in a light load state at this time; when the detected load current ILED is large, it is determined that the vehicle-mounted lamp 2 is working in a heavy load state at this time.

[0065] S102 , switching the on / off state of the gallium nitride switch module and the operating mode of the drive system based on the load current, where the operating modes include pulse width modulation mode, pulse frequency modulation mode, and burst mode.

[0066] It is understood that after the control module 12 determines the current operating state of the vehicle lamp 2 based on the load current ILED, the control module 12 also switches the on / off state of the GaN switch module 112 based on the detected load current ILED to change the dead time of the GaN switch module 112 and optimize the dead time, thereby ensuring that the drive system 1 maintains high efficiency and stability across the entire load range (i.e., light load and heavy load states). It is worth noting that by dynamically adjusting the on / off state of the GaN switch module 112, the output voltage of the GaN switch module 112 to the vehicle lamp 2 can be correspondingly changed, thereby adjusting the brightness of the vehicle lamp 2. In other words, the control module 12 can dynamically adjust the dead time in real time based on the load current ILED. This dead time can be extended under light load conditions to prevent body diode conduction, and shortened under heavy load conditions to improve efficiency.

[0067] The driving method provided in the present application also switches the working mode of the driving system 1 based on the detected load current ILED to adapt to different load conditions.

[0068] Exemplarily, the operating modes include a pulse width modulation (PWM) mode, a pulse frequency modulation (PFM) mode, and a burst mode.

[0069] The PWM mode is a technology for controlling output voltage or power by adjusting the duty cycle of a pulse signal. It can be understood that, in each cycle, the gallium nitride switching module 112 is turned on for a period of time (at this time, the control module 12 outputs a high level) and turned off for another period of time (at this time, the control module 12 outputs a low level). By changing the duty cycle (i.e., the on time) of the PWM signal output by the control module 12, the output voltage or power of the gallium nitride switching module 112 can be correspondingly changed, so as to correspondingly adjust the brightness of the LED array in the vehicle lamp 2. That is, at a fixed frequency, the on time of the gallium nitride switching module 112 is adjusted by changing the duration of the high level output to the gallium nitride switching module 112, so as to correspondingly change the output of the gallium nitride switching module 112, thereby correspondingly adjusting the brightness of the LED array in the vehicle lamp 2. The PWM mode can realize stable output voltage adjustment in a medium-high load state. Therefore, when the control module 12 determines that the vehicle lamp 2 is in a medium-high load state based on the detected load current ILED, the control module 12 correspondingly switches the working mode of the driving system 1 to the PWM mode, so that the driving system 1 can realize stable output voltage adjustment in a medium-high load state, thereby ensuring the adjustment efficiency and reliability.

[0070] The PFM mode is a technology for controlling output power by adjusting the switching frequency. It can be understood that, in each cycle, the on time of the gallium nitride switching module 112 remains unchanged (i.e., the pulse width remains unchanged), but the length of the entire cycle (frequency) changes. The higher the frequency, the more the on times per unit time; the lower the frequency, the fewer the on times per unit time. That is, at a fixed pulse width, the on-off cycle of the gallium nitride switching module 112 is controlled by adjusting the switching frequency. The PFM mode is generally suitable for a light load state. Therefore, when the control module 12 determines that the vehicle lamp 2 is in a light load state based on the detected load current ILED, the control module 12 correspondingly switches the working mode of the driving system 1 to the PFM mode. When the driving system 1 works in the PFM mode, the switching loss of the gallium nitride switching module 112 can be reduced by reducing the switching times, thereby improving the driving efficiency, so as to avoid unnecessary energy loss caused by the fixed frequency of PWM in a light load state.

[0071] The Burst mode is an energy-saving mode adopted in an extremely light load state or an idle state. In the Burst mode, the control module 12 turns off the gallium nitride switching module 112 for a long time and occasionally turns it on for a short time, so as to maintain the stability of the output voltage. That is, the gallium nitride switching module 112 is completely turned off for a period of time (without switching loss), and then turned on for a short time for several rounds to supplement energy. The periodic “sleep-wake” mechanism in the Burst mode greatly reduces the static power consumption.

[0072] In this way, when the control module 12 determines that the vehicle lamp 2 is under heavy load based on the load current ILED, the drive system 1 operates in PWM mode, allowing the GaN switch module 112 to output a stable output voltage to the vehicle lamp 2. When the control module 12 determines that the vehicle lamp 2 is under medium load based on the load current ILED, the drive system 1 can continue to operate in PWM mode, and the control module 12 can appropriately adjust the duty cycle of the output PWM signal to optimize efficiency. When the control module 12 determines that the vehicle lamp 2 is under light load based on the load current ILED, the drive system 1 operates in PFM mode, thereby reducing the switching frequency of the GaN switch module 112 to reduce losses. When the control module 12 determines that the vehicle lamp 2 is under very light load or no load based on the load current ILED, the drive system 1 operates in Burst mode, in which the drive system 1 operates intermittently to maintain a standby state and reduce energy consumption.

[0073] In summary, the driving method of the present application adopts a hybrid modulation strategy, namely, by using multiple modulation modes (PWM mode, PFM mode, and Burst mode) to adapt to operating conditions within different load ranges (i.e., from no-load to heavy-load). This allows the driving system 1 to automatically switch to the optimal control mode under different load conditions, maintaining high efficiency under heavy, medium, light, and no-load conditions, thereby improving the driving stability, reliability, and efficiency of the driving system 1. Furthermore, the driving method can dynamically select the most appropriate modulation mode based on the load state of the vehicle lamp 2, reducing unnecessary switching losses and static losses. Secondly, the driving system 1 of the present application is provided with a gallium nitride switch module 112. The gallium nitride devices in the gallium nitride switch module 112 have extremely low on-resistance and fast switching speed. They can replace the diodes used in related art to perform synchronous rectification, avoiding the rectification losses associated with diode rectification. Furthermore, compared to MOS switches, the gallium nitride switch module 112 has lower conduction and switching losses, reducing the switching losses of the switch, thereby further improving the driving stability and efficiency of the driving system 1. The high-frequency switching noise generated by the GaN switch module 112 when operating at high frequency is much lower than that of the MOS switch tube, and can meet the testing and requirement standards for high-frequency switching noise of vehicle-mounted electronic equipment in the industry.

[0074] Furthermore, the on-off state of the GaN switch module and the operating mode of the drive system are switched based on the load current. The operating modes include pulse width modulation mode, pulse frequency modulation mode and burst mode, including: When the load current is greater than or equal to the first threshold current, the drive system operates in a pulse width modulation mode.

[0075] When the load current is less than the first threshold current, the drive system operates in a pulse frequency modulation mode.

[0076] When the load current is less than the second threshold current, the drive system operates in a burst mode, and the second threshold current is less than the first threshold current.

[0077] It is understood that the control module 12 is configured with a first threshold current and a second threshold current. For example, assume that the first threshold current is 0.5A and the second threshold current is 0.1A. When the load current ILED detected by the control module 12 is greater than or equal to 0.5A, the vehicle lamp 2 is under heavy load, causing the drive system 1 to operate in PWM mode. In this case, the control module 12 controls the GaN switch module 112 to operate at a fixed frequency, such as 500kHz. In PWM mode, the GaN switch module 112 can output a stable output voltage to the vehicle lamp 2. When the load current ILED detected by the control module 12 is less than 0.5A, the vehicle lamp 2 is under light load, causing the drive system 1 to operate in PFM mode. In this case, the control module 12 controls the GaN switch module 112 to operate in pulse frequency modulation (PFM) mode, such as 100kHz-500kHz, thereby reducing the switching frequency of the GaN switch module 112 to reduce losses. When the load current ILED detected by the control module 12 is less than 0.1A, the vehicle lamp 2 is in an unloaded state, causing the drive system 1 to operate in Burst mode. The control module 12 then controls the gallium nitride switch module 112 to sleep in the next cycle to reduce static power consumption. The specific current values ​​of the first and second threshold currents can be set according to actual needs and are not specifically limited in this application.

[0078] In this way, the driving method predetermines a first threshold current and a second threshold current. The control module 12 compares the detected load current ILED with the first and second threshold currents to accurately determine the load state of the vehicle lamp 2 and switches the operating state of the driving system 1 accordingly, allowing the driving system 1 to automatically switch to the optimal control mode under different load conditions. This achieves high-efficiency driving under heavy, medium, light, and no-load conditions, improving the driving stability, reliability, and efficiency of the driving method.

[0079] Through the description of the above implementation methods, technical personnel in the relevant field can understand that for the convenience and simplicity of description, only the division of the above-mentioned functional modules is used as an example. In actual applications, the above-mentioned functions can be distributed and completed by different functional modules as needed, that is, the internal structure of the device can be divided into different functional modules to complete all or part of the functions described above.

[0080] In the embodiments provided in this application, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely schematic. For example, the division of modules or units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units or components can be combined or integrated into another device, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0081] The above content is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A driving system for a vehicle lamp, characterized in that: The drive system comprises: A single-ended primary inductor converter, the single-ended primary inductor converter comprising a power module and a gallium nitride switch module, the gallium nitride switch module being connected to the power module and the vehicle-mounted lamp; and A control module is connected to the gallium nitride switch module and the vehicle-mounted lamp. The control module is used to detect the load current of the vehicle-mounted lamp and switch the on-off state of the gallium nitride switch module and the operating mode of the drive system based on the load current. The operating modes include pulse width modulation mode, pulse frequency modulation mode and burst mode.

2. The drive system according to claim 1, characterized in that When the load current is greater than or equal to a first threshold current, the drive system operates in the pulse width modulation mode; When the load current is less than the first threshold current, the drive system operates in the pulse frequency modulation mode; When the load current is less than a second threshold current, the drive system operates in the burst mode; The second threshold current is smaller than the first threshold current.

3. The drive system according to claim 1, characterized in that The gallium nitride switch module includes: a first GaN high electron mobility transistor, wherein a drain of the first GaN high electron mobility transistor is connected to the vehicle lamp, and a gate of the first GaN high electron mobility transistor is connected to the control module; and a second GaN high electron mobility transistor, wherein a source of the second GaN high electron mobility transistor is connected to the vehicle lamp and the power module, a gate of the second GaN high electron mobility transistor is connected to the control module, and a drain of the second GaN high electron mobility transistor, a source of the first GaN high electron mobility transistor, and the power module are interconnected to form a common node; The control module is configured to send a high-side control signal to the gate of the first GaN high electron mobility transistor, and send a low-side control signal to the gate of the second GaN high electron mobility transistor.

4. The drive system according to claim 3, characterized in that: The power module includes: a power supply, wherein a negative electrode of the power supply is connected to a source electrode of the second GaN-HEMT; and an inductor, one end of the inductor being connected to the positive electrode of the power supply, and the other end of the inductor being connected to the common node.

5. The drive system according to claim 3, characterized in that: The drive system further comprises: A filter module, one end of which is connected to the drain of the first GaN-HEMT and the vehicle-mounted lamp, and the other end of which is connected to the source of the second GaN-HEMT and the vehicle-mounted lamp.

6. The drive system according to any one of claims 3 to 5, characterized in that: The first GaN high electron mobility transistor and the second GaN high electron mobility transistor operate in a zero voltage switching mode.

7. The drive system according to claim 1, characterized in that The drive system further comprises: A temperature compensation module is connected to the GaN switch module and the control module. The temperature compensation module is used to detect the junction temperature of the GaN switch module and send it to the control module. The control module is used to adjust the output current of the GaN switch module based on the junction temperature.

8. A method for driving a vehicle lamp, characterized in that: Applied to the drive system according to any one of items 1 to 7, the method comprises: Obtaining the load current of the vehicle-mounted lamp; The on-off state of the gallium nitride switch module and the working mode of the driving system are switched based on the load current, and the working mode includes a pulse width modulation mode, a pulse frequency modulation mode and a burst mode.

9. The driving method according to claim 8, wherein: The switching of the on / off state of the gallium nitride switch module and the operating mode of the drive system based on the load current, wherein the operating modes include the pulse width modulation mode, the pulse frequency modulation mode and the burst mode, includes: When the load current is greater than or equal to a first threshold current, the drive system operates in the pulse width modulation mode; When the load current is less than the first threshold current, the drive system operates in the pulse frequency modulation mode; When the load current is less than a second threshold current, the driving system operates in the burst mode, and the second threshold current is less than the first threshold current.

10. A vehicle, characterized in that: include: Vehicle lighting; as well as, The drive system according to any one of claims 1 to 7, wherein the drive system is connected to the vehicle-mounted lamp.

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