Illuminating system driver

Abstract

The invention relates to a constant-current / constant-voltage driving chip, which comprises at least one channel configured to provide constant-current or constant-voltage output for driven equipment; each channel includes: a constant current / constant voltage control unit configured to generate an inductive current command; the input end of the inductive current control unit is coupled to the output ends of the constant current / constant voltage control units of the channel and other channels in a controllable manner, and the inductive current control unit is configured to generate a switch control signal; the input end of the switching device is coupled to the output end of the inductive current control unit, and the switching device is configured to be switched on or switched off under the control of the switching control signal; wherein when at least two channels in the chip, or at least one channel in the chip and at least one channel in other chips work in a constant voltage mode, and the output ends of the channels are coupled with each other, the input ends of the inductive current control units of the channels are coupled with the output end of the constant current / constant voltage control unit of one channel in the channels, and the output ends of the inductive current control units of the channels are coupled with the output end of the constant current / constant voltage control unit of the other channels. And the switching control circuit is configured to generate a switching control signal under the inductive current instruction control of the channel.

Description

[0001] This application is a divisional application of the invention entitled "A Lighting System Driver", filed on July 24, 2023, with application number "2023109185375". Technical Field

[0002] This application relates to an electronic device, and more particularly to a lighting system driver. Background Technology

[0003] Lighting systems, such as those used in vehicles, typically consist of a driver and a lamp panel, such as an LED lamp panel. Because vehicles require different lighting effects depending on their driving conditions, the shape, number of LEDs, and drive current of the LED lamp panel vary depending on the specific lamp model and its light emission requirements. Currently, constant current driving is the primary method for automotive lighting systems. For example, high beams or low beams typically require a drive current of around 1A, with a maximum of no more than 1.6A. The number of LEDs connected in series can range from 5 to 12, with the required drive current and the number of LEDs varying depending on the brightness of the LEDs and the optical design of the lamp. Constant current driving in automotive lighting systems is usually achieved using dedicated constant current driver chips. Summary of the Invention

[0004] To address the technical problems existing in the prior art, this application proposes a constant current / constant voltage drive chip, including at least one or two channels configured to provide constant current or constant voltage output to the driven device; wherein, each channel includes: a constant current / constant voltage control unit configured to generate an inductor current command; an inductor current control unit whose input terminal is controllably coupled to the output terminal of the constant current / constant voltage control unit of this channel and the output terminals of the constant current / constant voltage control units of other channels, configured to generate a switch control signal; and a switching device whose input terminal is coupled to the output terminal of the inductor current control unit, configured to be turned on or off under the control of the switch control signal; wherein, when at least two channels of the chip, or at least one channel of the chip, and at least one channel of other chips are operating in constant voltage mode, and the output terminals of these channels are coupled to each other, the input terminals of the inductor current control units of these channels are all coupled to the output terminal of the constant current / constant voltage control unit of one of these channels, configured to generate a switch control signal under the control of the inductor current command of that channel. Specifically, the constant current / constant voltage control unit is configured to generate an inductor current command based on the relationship between the output current sampling signal of the channel and the preset output current setting or the relationship between the output voltage sampling signal of the channel and the preset output voltage setting.

[0005] Specifically, the inductor current control unit is configured to generate a switching control signal based at least on the relationship between the inductor current command from the channel in which it resides or from another channel and the inductor current sampling signal.

[0006] Specifically, the input of the inductor current control unit of each channel is also controllably coupled to an auxiliary connection and configured to receive inductor current commands from outside the chip.

[0007] Specifically, each channel includes a multiplexer, and the channels include a first channel and a second channel. The first input terminal of the multiplexer of the first channel is coupled to the output terminal of the constant current / constant voltage control unit of the first channel through a first switch, and the second input terminal of the multiplexer of the first channel is coupled to the output terminal of the constant current / constant voltage control unit of the second channel through a second switch. The first input terminal of the multiplexer of the second channel is coupled to the output terminal of the constant current / constant voltage control unit of the second channel through a second switch, and the second input terminal of the multiplexer of the second channel is coupled to the output terminal of the constant current / constant voltage control unit of the first channel through a first switch. When the constant current / constant voltage driver chip is operating in constant voltage mode, only one of the first switch and the second switch is turned on.

[0008] Specifically, the third input terminal of the first channel multiplexer and the third input terminal of the second channel multiplexer are configured via auxiliary wiring to receive inductor current commands from other chips in a controllable manner.

[0009] Specifically, the output of the constant current / constant voltage control unit of the first channel is also coupled to an auxiliary connection via a third switch, configured to provide the inductor current command of the second channel to other chips in a controllable manner; the output of the constant current / constant voltage control unit of the second channel is also coupled to an auxiliary connection via a fourth switch, configured to provide the inductor current command of the second channel to other chips in a controllable manner.

[0010] Specifically, the number of the plurality of channels is equal to or greater than the number of constant current / constant voltage control units in the chip. This application also provides a lighting system driver comprising one or more chips as described above, wherein the driver includes a controller coupled to each chip and configured to provide signals controlling the constant current or constant voltage mode of the chip and the on / off state of each switch; wherein, for each channel of each chip, the driver further includes a loop compensation device controllably coupled to the output of the constant current / constant voltage control unit of each channel.

[0011] This application also provides a lighting system including a driver as described above and a light-emitting device coupled thereto. Attached Figure Description

[0012] The preferred embodiments of this application will now be described in further detail with reference to the accompanying drawings, wherein: Figure 1 The diagram shown is a modular schematic of an existing vehicle lighting system; Figure 2 The diagram shown is a schematic representation of a vehicle lighting system according to an embodiment of this application. Figure 3(a) shows a schematic diagram of the circuit module of an existing vehicle lighting system driver that includes a constant current drive chip. Figure 3(b) shows a schematic diagram of the circuit module of one channel of the constant current drive chip in an existing vehicle lighting system driver. Figure 4(a) shows a schematic diagram of the circuit module of an existing vehicle lighting system driver that includes a constant current / constant voltage drive chip. Figure 4(b) shows a schematic diagram of the circuit module of one channel of the constant current / constant voltage drive chip in an existing vehicle lighting system driver. Figure 5 This is a schematic diagram of a circuit module for a vehicle lighting system driver according to an embodiment of this application; Figure 6 This is a schematic diagram of a circuit module for a vehicle lighting system driver according to another embodiment of this application; and Figure 7 This is a schematic diagram of the constant current / constant voltage drive chip and peripheral circuit structure in a vehicle lighting system according to an embodiment of this application. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0014] In the following detailed description, reference can be made to the accompanying drawings, which form part of this application and illustrate specific embodiments of the present application. In the drawings, similar reference numerals describe substantially similar components in different figures. Specific embodiments of the present application are described in sufficient detail below to enable those skilled in the art to implement the technical solutions of the present application. It should be understood that other embodiments may also be utilized, or structural, logical, or electrical changes may be made to the embodiments of the present application.

[0015] Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification. The lines connecting the units in the accompanying drawings are merely for illustrative purposes, indicating that at least the units at both ends of the line are communicating with each other, and are not intended to prevent unconnected units from communicating. Furthermore, the number of lines between two units is intended to indicate at least the number of signals involved in communication between the two units or at least the number of output terminals, and is not intended to limit communication between the two units to only the signals shown in the figures.

[0016] A transistor can refer to a transistor of any structure, such as a field-effect transistor (FET) or a bipolar junction transistor (BJT). When a transistor is a field-effect transistor, depending on the channel material, it can be hydrogenated amorphous silicon, metal oxide, low-temperature polycrystalline silicon, organic transistors, etc. Based on whether the charge carrier is electrons or holes, they can be divided into N-type transistors and P-type transistors. The gate of a field-effect transistor is its control electrode, and the first electrode can be either the drain or source, while the corresponding second electrode can be either the source or drain. When a transistor is a bipolar junction transistor (BJT), its control electrode is its base, and the first electrode can be either the collector or emitter, while the corresponding second electrode can be either the emitter or collector. Transistors can be manufactured using amorphous silicon, polycrystalline silicon, oxide semiconductors, organic semiconductors, NMOS / PMOS processes, or CMOS processes.

[0017] In this application, "in a controllable manner" refers to a configurable circuit control method implemented using circuit structures such as switches or switching transistors.

[0018] With the development of automotive electrification and intelligence, there is a demand for dynamic or animated lighting in vehicle lights. For example, many car models require turn signals to create flowing animations, where the LEDs or strings of LEDs light up sequentially when the turn signal is activated. This necessitates that the driver of the vehicle lighting system provide a constant voltage output while simultaneously supplying a larger current to the LED board with this new lighting method, enabling the linear drive chipset on the board to linearly drive the LEDs to produce such animation effects. However, the constant current drive chips in current common vehicle lighting system driver solutions cannot provide a constant voltage output. To meet requirements like the one described above, a separate constant voltage drive chip must be added to the vehicle lighting system driver to provide a constant voltage output.

[0019] At the same time, the hardware design of the vehicle lighting system driver should be as platform-based as possible, utilizing the same hardware structure to be compatible with different LED boards. For different LED boards, only the output current and other parameters of the vehicle lighting system driver need to be reconfigured in software to match the LED board to be driven; the hardware structure of the vehicle lighting system driver does not need to be redesigned.

[0020] Existing automotive lighting system drivers struggle to meet the demands of platform-based design and animated lighting effects. If the constant voltage and constant current requirements of the lights change, the hardware structure of the automotive lighting system driver must be modified accordingly.

[0021] Constant current / constant voltage driver chips that can meet both constant current and constant voltage requirements have emerged. Due to the limitations of LED chip technology and heat dissipation requirements, the maximum current output of these chips is usually no more than 1.6A; while the constant voltage output needs to drive multiple sets of parallel LED chips, and the maximum current is often greater than 1.6A, reaching, for example, 3~6A.

[0022] In practical applications, for cost-effectiveness reasons, each channel of the constant current / constant voltage driver chip in the automotive lighting system driver will prioritize compatibility with constant current applications, for example, setting the current to no more than 1.6A. In this case, if the lamp has constant voltage requirements, a single channel of the constant current / constant voltage driver chip in the automotive lighting system driver may not be able to provide a sufficiently large current for constant voltage output. If the LED lamp board requires constant voltage output and the required drive current exceeds 1.6A, then multiple channels of the constant current / constant voltage driver chip must be connected simultaneously to the linear LED driver chip group on the LED lamp board. Each channel is connected to one or more linear LED driver chips in the linear LED driver chip group, provided that the total rated current of these one or more linear LED driver chips is less than the maximum drive current of 1.6A that a single channel of the constant current / constant voltage driver chip can provide.

[0023] Figure 1 The diagram shows a module schematic of an existing vehicle lighting system. Figure 1 The exemplary vehicle lighting system driver shown includes four dual-channel constant current / constant voltage driver chips. This exemplary vehicle lighting system driver needs to drive four different types of lights: high beam, low beam, turn signals, and welcome lights.

[0024] High beam and low beam are lamps that require constant current, so their LED lamp boards only need to be connected to one channel of the constant current / constant voltage driver chip in the vehicle lighting system driver to obtain constant current output.

[0025] Turn signals and welcome lights are lighting fixtures requiring constant voltage. The linear LED driver chipset on the turn signal LED board can include, for example, two 16-channel linear LED driver chips, each with a rated current of 60mA. That is, the rated current of one linear LED driver chip is 0.96A, and the drive current required for the turn signal LED board is 1.92A, which is greater than the maximum current of 1.6A that a single channel of the constant current / constant voltage driver chip in the exemplary automotive lighting system driver can provide. Therefore, Figure 1 The constant current / constant voltage driver chip of the exemplary vehicle lighting system driver shown must provide two channels, which are respectively connected to one of the linear LED driver chips in the linear LED driver chip group on the turn signal LED board, together providing constant voltage output and sufficiently large drive current to the turn signal LED board.

[0026] Similarly, the linear LED driver chipset on the welcome light LED panel may include, for example, four 16-channel linear LED driver chips, each with a rated current of 60mA. That is, the rated current of one linear LED driver chip is 0.96A, and the drive current required for the turn signal LED panel is 3.84A. Although the maximum current that the three channels of the constant current / constant voltage driver chip in the exemplary automotive lighting system driver can provide already exceeds 3.84A, due to... Figure 1 Due to limitations in existing automotive lighting systems, one channel of the constant current / constant voltage driver chip can only be connected to one linear LED driver chip on the LED light board. Therefore, Figure 1 The exemplary vehicle lighting system driver shown must provide four channels, each connected to one of the linear LED driver chips in the linear LED driver chip group on the welcome light LED panel, to provide constant voltage output and sufficiently large drive current to the turn signal LED panel.

[0027] The above examples Figure 1 While the solution shown is compatible with the constant current and constant voltage requirements of the lamps, it firstly significantly increases the cost and hardware complexity of the linear LED driver chipset on the LED lamp board. At the same time, this solution wastes the channel resources of the constant current / constant voltage driver chip in the vehicle lighting system driver, which also significantly increases the power consumption, overall cost, hardware complexity and space occupation of the vehicle lighting system driver, which is very unfavorable for practical applications.

[0028] This application aims to provide a vehicle lighting system driver compatible with various types of LED light panels, which adjusts the driver output mode through software settings without changing the hardware structure of the vehicle lighting system driver, while simplifying the hardware connection between the vehicle lighting system driver and the LED light panel.

[0029] Figure 2The diagram shown is a schematic diagram of a vehicle lighting system according to an embodiment of this application. Figure 2 In the exemplary automotive lighting system driver shown, the channels of the constant current / constant voltage chips can be connected in parallel, allowing a drive current exceeding the maximum current provided by a single channel to be supplied to the linear LED driver chipset of the LED light board through a unified output terminal. This more flexibly balances the constant voltage output of the lamp and the requirement for a large drive current. In this way, the individual chips in the linear LED driver chipset of the LED light board do not need to be individually connected to different channels of the constant current / constant voltage driver chips in the automotive lighting system driver.

[0030] Figure 3(a) shows a schematic diagram of a circuit module of an existing automotive lighting system driver that includes a constant current drive chip. Figure 3(b) shows a schematic diagram of a circuit module of one channel of the constant current drive chip in an existing automotive lighting system driver.

[0031] As shown in Figure 3(a), the existing constant current driver chip includes a constant current control unit, an inductor current control unit, and a switching device that are coupled to each other. The switching device is turned on or off under the control of the signal generated by the inductor current control unit. The output signal is filtered by a passive filter device composed of Lout and Cout to generate a smooth current output to the LED board. The current is sampled by the sampling resistor RS and then transmitted back to the constant current control unit of the constant current driver chip.

[0032] As shown in Figure 3(b), the constant current control unit of the constant current driver chip typically includes an error amplifier (usually a voltage-current amplifier Gm) that compares the output current sample with the output current setting (reference current value) and transmits this information to a loop compensation device. The loop compensation device typically includes a capacitor, or a resistor connected in series with a capacitor. The loop compensation device is usually located outside the constant current driver chip so that the user can adjust the device to meet desired dynamic characteristics. The output of the constant current control unit represents an inductor current command with a stable current value, which is transmitted to one input of the inductor current control unit of the constant current driver chip. The other input of the inductor current control unit is configured to receive an inductor current sample and control the on or off state of the switching device based on the relationship between the sampled inductor current value and the inductor current command.

[0033] Figure 4(a) shows a schematic diagram of a circuit module of an existing automotive lighting system driver that includes a constant current / constant voltage driver chip. Figure 4(b) shows a schematic diagram of a circuit module of one channel of the constant current / constant voltage driver chip in an existing automotive lighting system driver.

[0034] The constant current / constant voltage control unit in the constant current / constant voltage drive chip no longer directly compares the output current sample and the output current setting (reference current value) with the error amplifier. Instead, it selects the source of the setting value and the sampled value through a multiplexer (MUX) and then sends them to the error amplifier to achieve the switching of control quantity.

[0035] Figure 4(b) shows a schematic diagram of a circuit module, illustrating one possible implementation of a channel in this type of constant current / constant voltage driver chip. The selection and switching of control quantities are accomplished by the microcontroller (MCU) on the vehicle lighting system driver and the communication and control module on the constant current / constant voltage driver chip.

[0036] When the constant current / constant voltage driver chip in the automotive lighting system driver provides a constant voltage output, the output voltage may have a slight deviation in the set value due to parameter offsets. According to circuit theory, voltage sources with unequal voltages cannot be directly connected in parallel. Direct parallel connection will cause a large current to be generated between the voltage sources, leading to a decrease in voltage source efficiency or even damage. One option is to connect the loop compensation devices of the two channels outside the constant current / constant voltage driver chip together with a wire. However, although this solution achieves parallel connection of constant voltage output channels, it still cannot meet the requirements of hardware platformization for the automotive lighting system driver.

[0037] First, connecting the loop compensation devices of different channels off-chip with wires is itself a hardware modification; second, the parallel connection of capacitors of the loop compensation devices of different channels causes changes in the compensation parameters, requiring the removal of a capacitor or a change in the capacitor value, which will involve more hardware modifications beyond the constant current / constant voltage driver chip.

[0038] The purpose of this application is to achieve both parallel connection of constant voltage output channels of constant current / constant voltage driver chips and to meet the requirements of hardware platformization for automotive lighting system drivers, without modifying the hardware, but only through software configuration to achieve parallel connection of constant voltage output channels. Based on this concept, this application proposes a novel constant current / constant voltage driver chip that can meet the requirements of constant current and constant voltage output without changing the hardware structure of the automotive lighting system driver, only through software configuration. Furthermore, in constant voltage output mode, depending on the required drive current of the driven lamp, it can not only enable a single channel to independently provide constant voltage output and drive current to the LED board of the driven lamp, but also enable any number of channels to be connected in parallel to provide constant voltage output and drive current to the LED board of the driven lamp through a unified output terminal; "Any number of channels in parallel" includes both any number of channels within the same chip and any number of channels between different chips. The parallel connection of multiple channels mentioned in this application refers to the coupling of the output terminals of each channel, for example, the coupling of the output terminals of each channel through corresponding passive filter circuits.

[0039] Figure 5This is a schematic diagram of a circuit module for a vehicle lighting system driver according to an embodiment of this application.

[0040] According to one embodiment, Figure 5 The exemplary vehicle lighting system driver shown may include a dual-channel constant current / constant voltage driver chip.

[0041] According to one embodiment, Figure 5 The exemplary vehicle lighting system driver shown may include a constant current / constant voltage control unit, an inductor current control unit, and a switching device, which are arranged in a constant current / constant voltage driver chip and coupled to each other.

[0042] According to one embodiment, Figure 5 The exemplary vehicle lighting system driver shown may include, for example, a loop compensation device, a filter device consisting of Lout and Cout, and an RS sampling device arranged outside the constant current / constant voltage driver chip, respectively, in channels 1 and 2.

[0043] According to one embodiment, Figure 5 The exemplary vehicle lighting system shown may also include a set of lamps that require a constant voltage output from a driver. The driving current required by the lamps is greater than the maximum current that one channel in the constant current / constant voltage driver chip can provide, but less than the maximum current that two channels can provide. Therefore, it is necessary to implement the parallel connection of two channels within the same constant current / constant voltage driver chip.

[0044] To achieve the above requirements, necessary circuit components can be added during the design and manufacturing stage of the constant current / constant voltage driver chip (exemplary embodiments of the specific circuits are described later in the specification). According to one embodiment, the internal connection relationship of the constant current / constant voltage driver chip can be changed through software configuration, and each channel can be configured to achieve parallel connection between any channels within the constant current / constant voltage driver chip.

[0045] To achieve the above parallel connection, it is necessary to ensure that the output voltages of the two channels are essentially the same. According to one embodiment, this is achieved through software configuration. Figure 5 The constant current / constant voltage control unit of channel 2 can be disabled, or in other words, prevented from providing inductor current commands. The inductor current control unit of channel 2 can be coupled to the constant current / constant voltage control unit of channel 1, receiving its output inductor current commands to control the switching devices of channel 2. Furthermore, this coupling relationship is implemented internally within the constant current / constant voltage chip.

[0046] At this time, only the constant current / constant voltage control unit of channel 1 in the constant current / constant voltage drive chip works in constant voltage control mode. The inductor current control units of channel 1 and channel 2 receive the same inductor current command from the constant current / constant voltage control unit of channel 1. Therefore, the output voltage of channel 1 and channel 2 is the same, and the two constant voltage output channels can be connected in parallel.

[0047] According to one embodiment, in the above parallel configuration, the loop compensation device (e.g., capacitor) in channel 2 can also be disconnected from other parts of the vehicle lighting system driver by software configuration, thereby avoiding the problem of the loop compensation device (capacitor) in channel 2 being coupled to the loop compensation device (capacitor) in channel 1 due to the inductor current control unit in channel 2 being coupled to the constant current / constant voltage control unit in channel 1.

[0048] In conclusion, Figure 5 The exemplary vehicle lighting system driver shown can use parallel channels 1 and 2 to provide a constant voltage output to the LED board of the lamp via a unified output terminal, while providing a drive current that combines the currents of the two channels to the LED board of the lamp.

[0049] According to other embodiments, Figure 5 The two channels in the exemplary vehicle lighting system driver shown can also be configured by software to operate in other modes (not shown) depending on the constant current or constant voltage requirements of the lamps in the vehicle lighting system and the magnitude of the required drive current.

[0050] According to one embodiment, Figure 5 The exemplary vehicle lighting system shown may include two sets of lamps (not shown), both of which require constant voltage output, but the required drive current is less than the maximum current that a single channel can provide.

[0051] At this point, channel 1 and channel 2 can be directly connected to the LED panels of one group of lamps, respectively. Through software configuration, channel 1 and channel 2 can both operate in independent constant voltage output mode. Channel 1 independently provides constant voltage output and drive current to the LED panels of one group of lamps, while channel 2 independently provides constant voltage output and drive current to the LED panels of the other group of lamps.

[0052] According to another embodiment, Figure 5 The exemplary vehicle lighting system shown may include two sets of lamps (not shown), one set of lamps requiring constant voltage output but requiring a drive current less than the maximum current that a single channel can provide; the other set of lamps requiring constant current output.

[0053] At this point, channel 1 and channel 2 can still be directly connected to the LED panels of a set of lamps separately. However, through software configuration, channel 1 can operate in independent constant voltage output mode, and channel 2 can operate in independent constant current output mode. Channel 1 independently provides constant voltage output and drive current to the LED panels of lamps requiring constant voltage output, while channel 2 independently provides constant current output to the LED panels of lamps requiring constant current output.

[0054] Figure 6 This is a schematic diagram of a circuit module for a vehicle lighting system driver according to another embodiment of this application.

[0055] According to one embodiment, Figure 6 The exemplary vehicle lighting system driver shown may include two dual-channel constant current / constant voltage driver chips: constant current / constant voltage driver chip 1 and constant current / constant voltage driver chip 2.

[0056] According to one embodiment, Figure 6 The exemplary vehicle lighting system driver shown may include a constant current / constant voltage control unit, an inductor current control unit, and a switching device, which are arranged in and coupled to each other in the constant current / constant voltage drive chip 1.

[0057] According to one embodiment, Figure 6 The exemplary vehicle lighting system driver shown may include a loop compensation device, a filter device consisting of Lout and Cout, and an RS sampling device, respectively, arranged outside the constant current / constant voltage driver chip 1.

[0058] According to one embodiment, Figure 6 The exemplary vehicle lighting system driver shown may include channels 3 and 4, which are arranged in the constant current / constant voltage driver chip 2 and coupled to each other, a constant current / constant voltage control unit, an inductor current control unit, and a switching device.

[0059] According to one embodiment, Figure 6 The exemplary vehicle lighting system driver shown may include a loop compensation device, a filter device consisting of Lout and Cout, and an RS sampling device, respectively, arranged outside the constant current / constant voltage driver chip 2.

[0060] According to one embodiment, Figure 6The exemplary vehicle lighting system shown may also include two sets of lamps: lamp 1 and lamp 2. Lamp 2 requires a constant current output from the vehicle lighting system driver; lamp 1 requires a constant voltage output from the vehicle lighting system driver. The drive current required by lamp 1 is greater than the maximum current that two channels in the constant current / constant voltage driver chip can provide, but less than the maximum current that three channels can provide. Therefore, the three constant voltage output channels need to be connected in parallel between constant current / constant voltage driver chip 1 and constant current / constant voltage driver chip 2.

[0061] To achieve the above requirements, according to one embodiment, necessary circuit components (exemplary embodiments of the specific circuits are described later in the specification) can be added during the design and manufacturing stage of the constant current / constant voltage driver chip, and auxiliary wiring can be used to pre-connect all the constant voltage / constant current driver chips in the vehicle lighting system driver. According to one embodiment, the internal connection relationships of the constant current / constant voltage driver chips can be changed through software configuration to configure all channels in the vehicle lighting system driver. According to one embodiment, for each channel in the vehicle lighting system driver, depending on the constant current or constant voltage output requirements of the LED lamp board and the required drive current, it can be configured as an independent constant current or constant voltage output channel, or it can be configured to connect in parallel with channels on other constant current / constant voltage driver chips via auxiliary wiring to achieve constant voltage output channels between different chips, or the auxiliary wiring can be left unconnected to achieve parallel constant voltage output channels within the same constant current / constant voltage driver chip.

[0062] This embodiment illustrates an example of implementing three constant voltage output channels in parallel among different chips, and a single channel providing a constant current output. Specifically, channel 3 in constant current / constant voltage driver chip 2 is connected in parallel with channels 1 and 2 in constant current / constant voltage driver chip 1, providing a constant voltage output to the LED board of lamp 1 via a unified output terminal, while simultaneously providing a drive current that combines the currents of the three channels to the LED board of lamp 1. According to one embodiment, Figure 6 The auxiliary connections are respectively coupled to the input terminals of the inductor current control units of channels 1 to 4 in constant current / constant voltage drive chip 1 and constant current / constant voltage drive chip 2.

[0063] Specifically, to achieve the above parallel connection, according to one embodiment, point A1 of channel 1 and point A1' of channel 2 in the constant current / constant voltage driver chip 1 can be coupled to each other through software configuration. The constant current / constant voltage control units and loop compensation devices of channels 1 and 2 are disconnected from channels 1 and 2, respectively. The constant current / constant voltage control unit of channel 3 operates in constant voltage output main channel mode. In addition to providing inductor current control unit of channel 3, it also provides the same inductor current control unit of channels 1 and 2 using auxiliary connections. Therefore, the voltages of channels 1 to 3 are the same, enabling the parallel connection of three constant voltage output channels.

[0064] According to one embodiment, in order to provide a constant current output to lamp 2, such as Figure 6 As shown, the A2' point of channel 4 can be disconnected from the auxiliary connection through software configuration. The constant current / constant voltage control unit of channel 4 operates in independent constant current output mode and is configured to output inductor current control unit of channel 4. Channel 4 provides constant current output for lamp 2 as an independent constant current output channel.

[0065] According to one embodiment, although the auxiliary connections are connections other than the constant current / constant voltage driver chips, they are connected to each other before the loop compensation devices, so that no coupling is caused between the loop compensation devices of each parallel channel when the channels are connected in parallel.

[0066] According to other embodiments, Figure 6 The four channels in the exemplary automotive lighting system driver shown can also be configured by software to operate in other modes (not shown) depending on the constant current or constant voltage requirements of the lamps in the lighting system and the required drive current. For example, each channel can be configured by software as an independent constant current output mode, an independent constant voltage output mode, a master channel in a constant voltage output mode with multiple channels in parallel, or a slave channel in a constant voltage output mode with multiple channels in parallel. The constant voltage output mode with multiple channels in parallel can be either a parallel connection of multiple channels within the same constant current / constant voltage driver chip or a parallel connection of multiple channels between different constant current / constant voltage driver chips.

[0067] Figure 7 This is a schematic diagram of the constant current / constant voltage drive chip and peripheral circuit structure in a vehicle lighting system according to an embodiment of this application.

[0068] According to one embodiment, Figure 7 The exemplary vehicle lighting system driver shown may include a dual-channel constant current / constant voltage driver chip.

[0069] According to one embodiment, Figure 7 The exemplary vehicle lighting system driver shown may include channel 1 and channel 2, which may be coupled to each other, a constant current / constant voltage control unit, an inductor current control unit, and a switching device.

[0070] According to one embodiment, Figure 7 The exemplary vehicle lighting system driver shown may include a loop compensation device, a filter device consisting of Lout and Cout, and an RS sampling device, respectively, arranged outside the constant current / constant voltage driver chip.

[0071] According to one embodiment, Figure 7The exemplary vehicle lighting system driver shown may include a multiplexer MUX1 in channel 1 and a multiplexer MUX2 in channel 2.

[0072] According to one embodiment, MUX1 is coupled between the inductor current control unit and the constant current / constant voltage control unit of channel 1. According to one embodiment, MUX1 may include three input terminals configured to receive three different input signals and select one of them to output to the inductor current control unit of channel 1.

[0073] According to one embodiment, the first input terminal of MUX1 is coupled to the output terminal of the constant current / constant voltage control unit of channel 1 via switch S1 to receive signal Vcomp1. The second input terminal of MUX1 receives signal Vcomp2 from the constant current / constant voltage control unit of channel 2. The third input terminal of MUX1 receives signal Vpal1 output from the constant current / constant voltage control unit in other constant current / constant voltage driver chips via an auxiliary connection. According to one embodiment, the third input terminal of MUX1 can also output signal Vcomp1 from the constant current / constant voltage control unit of channel 1 via switch S3.

[0074] According to one embodiment, the MUX2 is coupled between the inductor current control unit and the constant current / constant voltage control unit of channel 2. According to another embodiment, the MUX2 may include three input terminals configured to receive three different input signals and select one of them to output to the inductor current control unit of channel 2.

[0075] According to one embodiment, the first input terminal of MUX2 is coupled to the output terminal of the constant current / constant voltage control unit of channel 2 via switch S2 to receive signal Vcomp2. The second input terminal of MUX2 receives signal Vcomp1 from the constant current / constant voltage control unit of channel 1. The third input terminal of MUX2 receives signal Vpal1 output from the constant current / constant voltage control unit in other constant current / constant voltage driver chips via an auxiliary connection. According to one embodiment, the third input terminal of MUX2 can also output signal Vcomp2 from the constant current / constant voltage control unit of channel 2 via switch S4.

[0076] According to one embodiment, Figure 7 The exemplary vehicle lighting system driver shown may also include a microcontroller (MCU) and a communication & control module, both configured to control the states of switches S1 to S4 according to the characteristics of the LED light panel and the requirements for the lighting effect, thereby controlling the operating state of the constant current / constant voltage drive chip.

[0077] According to one embodiment, to Figure 7Taking channel 1 in the exemplary vehicle lighting system driver as an example, Table 1 lists the different configurations of all switches (switches S1, S3) and multiplexer (MUX1) in channel 1 when it is in different operating modes.

[0078]

[0079] Depending on the implementation, each channel of the constant current / constant voltage drive chip in the automotive lighting system driver may or may not include a constant current / constant voltage control unit. That is, the number of constant current / constant voltage control units included in the automotive lighting system driver can be less than or equal to the number of channels. In practical applications, the constant current / constant voltage control units can be connected to the corresponding channels in a controllable manner according to the actual requirements of parallel connection of channels in the automotive lighting system driver.

[0080] Depending on the specific implementation, the number of constant current / constant voltage driver chips included in the vehicle lighting system driver can be varied according to the actual application requirements.

[0081] Depending on the specific implementation, the number of channels in a constant current / constant voltage driver chip can be varied according to the actual application requirements.

[0082] Depending on the specific implementation, the circuitry for selecting and switching control quantities in the constant current / constant voltage drive chip can be implemented in different ways. In other words, it may not necessarily be implemented through a MUX, but in other ways as well.

[0083] In summary, this application proposes a novel constant voltage / constant current driver chip. It can fully meet constant current and constant voltage output requirements simply by software configuration without modifying the hardware structure of the vehicle lighting system driver. Furthermore, it enables parallel connection of any number of channels during constant voltage output, including parallel connection of any number of channels within the same constant current / constant voltage driver chip, as well as parallel connection of any number of channels between different constant current / constant voltage driver chips. This satisfies the diverse constant current and constant voltage requirements of the driven devices while also meeting the requirements of a driver hardware platform. Moreover, all the circuit components involved in this application can be implemented within the constant current / constant voltage driver chip, offering significant advantages in space saving and cost reduction compared to solutions that require external circuit modifications.

[0084] The above embodiments use LED vehicle lighting systems for illustration, but without exceeding the scope of protection of this application, they can also be applied to other vehicles or other devices with similar application scenarios.

[0085] This application provides a method for driving a lighting device in constant voltage mode, wherein the driver of the lighting device may include at least one constant current / constant voltage driver chip, which may include multiple channels. The constant current / constant voltage control unit of one channel can output inductor current control units of the same channel and other channels to output inductor current commands, thereby making the output voltage of multiple channels the same, thereby realizing the parallel connection of multiple channels.

[0086] This application provides a method for driving a lighting device in constant voltage mode, wherein the driver of the lighting device may include at least a plurality of constant current / constant voltage driver chips, each chip may include multiple channels, and the constant current / constant voltage control unit of one channel of one chip and the inductor current control unit of other channels on the same or different chips may be used to output inductor current commands, thereby making the output voltage of multiple channels within the same chip or between different chips the same, thereby realizing the parallel connection of multiple channels within the same chip or between different chips.

[0087] The above embodiments are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art can make various changes and modifications without departing from the scope of this application. Therefore, all equivalent technical solutions should also fall within the scope of this application.

Claims

1. A constant current / constant voltage driver chip, comprising: At least one channel is configured to provide a constant current or constant voltage output to the driven device; wherein each of the channels includes: A constant current / constant voltage control unit is configured to generate inductor current commands; An inductor current control unit, the input of which is controllably coupled to the output of the constant current / constant voltage control unit of this channel and the output of the constant current / constant voltage control unit of other channels, is configured to generate a switching control signal; A switching device, the input of which is coupled to the output of the inductor current control unit, is configured to be turned on or off under the control of the switching control signal; Wherein, when at least two channels in the chip, or at least one channel in the chip, are all operating in constant voltage mode, and the output terminals of these channels are coupled to each other, the input terminals of the inductor current control units of these channels are all coupled to the output terminal of the constant current / constant voltage control unit of one of these channels, and are configured to generate a switching control signal under the inductor current command control of that one channel.

2. The chip as described in claim 1, wherein, The constant current / constant voltage control unit is configured to generate the inductor current command based on the relationship between the output current sampling signal of the channel and the preset output current setting or the relationship between the output voltage sampling signal of the channel and the preset output voltage setting.

3. The chip as described in claim 1, wherein, The inductor current control unit is configured to generate the switching control signal based at least on the relationship between the inductor current command from the channel in which it resides or another channel and the inductor current sampling signal.

4. The chip as described in claim 1, wherein, The input terminal of the inductor current control unit of each channel is also controllably coupled to the auxiliary connection and configured to receive inductor current commands from outside the chip.

5. The chip of claim 1, wherein each channel includes a multiplexer, and the channel includes a first channel and a second channel; The first input terminal of the multiplexer of the first channel is coupled to the output terminal of the constant current / constant voltage control unit of the first channel through a first switch, and the second input terminal of the multiplexer of the first channel is coupled to the output terminal of the constant current / constant voltage control unit of the second channel through a second switch; The first input terminal of the multiplexer of the second channel is coupled to the output terminal of the constant current / constant voltage control unit of the second channel through the second switch, and the second input terminal of the multiplexer of the second channel is coupled to the output terminal of the constant current / constant voltage control unit of the first channel through the first switch; When the constant current / constant voltage drive chip is operating in constant voltage mode, only one of the first switch and the second switch is turned on.

6. The chip as claimed in claim 5, wherein The third input terminal of the multiplexer of the first channel and the third input terminal of the multiplexer of the second channel are configured via the auxiliary connection to receive inductor current commands from other chips in a controllable manner.

7. The chip of claim 5, wherein the output terminal of the constant current / constant voltage control unit of the first channel is further coupled to the auxiliary connection via a third switch, configured to provide the inductor current command of the second channel to other chips in a controllable manner; the output terminal of the constant current / constant voltage control unit of the second channel is further coupled to the auxiliary connection via a fourth switch, configured to provide the inductor current command of the second channel to other chips in a controllable manner.

8. The chip of claim 1, wherein the number of the plurality of channels is equal to or greater than the number of constant current / constant voltage control units in the chip.

9. A lighting system driver comprising one or more chips as claimed in any one of claims 1-8, wherein the driver includes a controller coupled to each of the chips and configured to provide signals for controlling the constant current or constant voltage mode of the chips and the on state of each switch; in, For each channel of each chip, the driver also includes a loop compensation device that is controllably coupled to the output of the constant current / constant voltage control unit of each channel.

10. A lighting system comprising the driver as described in claim 9 and a light-emitting device coupled thereto.

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