A car single RGB lamp bead atmosphere light driving system based on integrated LDO

Abstract

The present invention relates to a single RGB lamp bead atmosphere lamp driving system for automobiles based on integrated LDO. It includes an LDO module, which is connected to the vehicle voltage and is used to step down the vehicle voltage to a stable output voltage; the LDO module includes a reference voltage module, a voltage divider module, an operational amplifier, a current clamping module and a MOS tube; an RGB lamp bead, which is connected to the output voltage; a driving module, which includes a PWM control module and a current digital-to-analog conversion module; the PWM control module is used to generate a PWM modulation signal and control the duty cycle of the RGB lamp bead; the current digital-to-analog conversion module is connected to the RGB lamp bead; a logic control module is connected to the automobile ECU communication, and is respectively connected to the LDO module and the driving module, and reduces the driving current according to the current clamping signal. The present invention effectively reduces the voltage drop loss in the driving link, thereby improving the current output capacity of the driving circuit, and finally realizes the demand for high-brightness lighting.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile cockpit atmosphere, and in particular to an automobile single RGB lamp bead atmosphere lamp driving system based on an integrated low-dropout linear regulator (LDO). Background Art

[0002] With the continuous improvement of automobile intelligence and personalization, the in-vehicle ambient light is no longer limited to a single lighting function, but has gradually developed into an important interactive carrier to enhance the driving experience. Modern car ambient lights not only play the role of ambient lighting, but also create an immersive in-car atmosphere and enhance driving pleasure and comfort through color changes, dynamic effects and linkage with the in-vehicle system. However, the current in-vehicle ambient light technology based on single lamp beads (such as RGB LED) still faces many technical bottlenecks in practical applications. These bottlenecks limit its visual performance and user experience in complex dynamic environments. The specific performance is as follows: The current mainstream single-bead automotive ambient light solutions usually use a method of directly obtaining power from the car battery and transmitting it to the LED lamp beads for power supply. However, this direct drive method has a large energy loss during the power supply process, mainly due to the voltage drop loss of the drive circuit, which makes the overall energy efficiency of the system low. At the same time, due to the fluctuation of the car battery voltage, the direct power supply method has weak current control ability for the LED lamp beads, which may cause unstable brightness, thereby affecting the display consistency and dynamic adjustment effect of the ambient light. In addition, due to the limitation of current driving capability, the existing solutions are difficult to meet the balance between power consumption and thermal management under high-brightness lighting requirements, affecting the service life of the LED lamp beads. Summary of the invention

[0003] To this end, the present invention provides an automotive single RGB lamp bead atmosphere lamp driving system based on integrated LDO. Through the design of integrated LDO (low dropout linear regulator), the voltage drop loss in the driving link is effectively reduced, thereby improving the current output capacity of the driving circuit, and finally achieving the demand for high-brightness lighting.

[0004] In order to solve the above technical problems, the present invention provides an automotive single RGB lamp bead atmosphere lamp driving system based on integrated LDO, comprising: The LDO module is connected to the vehicle voltage and is used to step down the vehicle voltage to a stable output voltage; the LDO module includes a reference voltage module, a voltage divider module, an operational amplifier, a current clamp module and a MOS tube, the operational amplifier is used to compare the reference voltage generated by the reference voltage module and the voltage divider module to control the MOS tube to generate the output voltage; the current clamp module monitors the current flowing through the MOS tube, and when the current reaches a set threshold, it can trigger a current clamp signal; RGB lamp beads, connected to the output voltage; A driving module, the driving module comprising a PWM control module and a current digital-to-analog conversion module; the PWM control module is used to generate a PWM modulation signal and control the duty cycle of the RGB lamp beads to adjust their brightness; the current digital-to-analog conversion module is connected to the RGB lamp beads, and dynamically adjusts the driving current of the RGB lamp bead module according to the PWM modulation signal; The logic control module is connected to the automobile ECU for communication and is respectively connected to the LDO module and the drive module. The control module is used to receive the control signal of the automobile ECU and reduce the drive current according to the current clamp signal.

[0005] In one embodiment of the present invention, the drain of the MOS tube is connected to the input voltage, the source is connected to the output voltage, and the gate is connected to the output end of the operational amplifier; The reference voltage module is respectively connected to the input voltage and the inverting input terminal of the operational amplifier; The voltage divider module includes a first resistor and a second resistor, the in-phase input end of the operational amplifier is connected between one end of each of the first resistor and the second resistor, the other end of the first resistor is connected to the source of the MOS tube, and the other end of the second resistor is grounded; The input end of the current clamp module is connected to the output end of the operational amplifier, and the output end of the current clamp module is connected to the logic control module.

[0006] In one embodiment of the present invention, the output voltage is 5V.

[0007] In one embodiment of the present invention, the logic control module is communicatively connected to the automobile ECU via a LIN physical layer.

[0008] In one embodiment of the present invention, a diode and a filter capacitor are further included, the vehicle-mounted voltage is connected to the positive electrode of the diode, the negative electrode of the diode is grounded through the filter capacitor, and an input voltage is formed between the negative electrode of the diode and the filter capacitor.

[0009] The above technical solution of the present invention has the following advantages compared with the prior art: The present invention discloses a single RGB lamp bead automotive atmosphere lamp driving system based on integrated LDO, which effectively reduces the voltage drop loss in the driving link through the design of integrated LDO (low dropout linear regulator), thereby improving the current output capacity of the driving circuit, and finally achieving the demand for high-brightness lighting. In addition, it also has the following advantages: By reducing the voltage drop of the driving part, the present invention improves its current output capability, so that the system can provide a higher output current under the same input power. When the total input current remains unchanged, the system can support a higher brightness output and improve the luminous efficiency of RGBLED, thereby enhancing the overall visual expression.

[0010] The present invention sets a current clamping module to monitor the current flowing through the MOS tube in real time, and triggers a current clamping signal to limit the output current when the current exceeds the set threshold. This process can effectively prevent system failures caused by overload or abnormal conditions, and improve the safety and reliability of the system. The problem of the lack of precise current management in traditional solutions is solved. The current clamping mechanism of the present invention ensures that the LED load will not be damaged due to overcurrent, and improves the stability of the vehicle-mounted atmosphere light system.

[0011] The logic control module of the present invention receives the ILIMIT signal and adjusts the current output of the driving part: by reducing the duty cycle of the PWM control module, the LED brightness is reduced and the power consumption is reduced. By adjusting the current digital-to-analog conversion module, the LED color performance is further optimized to maintain color consistency at different brightness. Traditional LED brightness control mainly relies on PWM (pulse width modulation), but in low brightness state, the PWM duty cycle is relatively small, which may cause LED flickering or uneven brightness.

[0012] The logic control module of the present invention communicates with the automobile ECU through the LIN physical layer, realizes intelligent control, and reduces system complexity and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to make the contents of the present invention more clearly understood, the present invention is further described in detail below based on specific embodiments of the present invention in conjunction with the accompanying drawings.

[0014] Figure 1 The present invention is a schematic diagram of a single RGB lamp bead automotive atmosphere lamp driving system with integrated LDO.

[0015] Figure 2 It is a schematic diagram of an LDO module with current clamping function of the present invention.

[0016] Figure 3 It is a schematic diagram of the driving part of the present invention. DETAILED DESCRIPTION

[0017] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0018] In the present invention, if directions (up, down, left, right, front and back) are described, it is only for the convenience of describing the technical solution of the present invention, and does not indicate or imply that the technical features referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, it cannot be understood as a limitation of the present invention.

[0019] In the present invention, "several" means one or more, "multiple" means more than two, "greater than", "less than", "exceed" and the like are understood to exclude the number itself; "above", "below", "within" and the like are understood to include the number itself. In the description of the present invention, if there is a description of "first" or "second", it is only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0020] In the present invention, unless otherwise clearly defined, the words "set", "install", "connect" and the like should be understood in a broad sense, for example, they can be directly connected or indirectly connected through an intermediate medium; they can be fixedly connected or detachably connected or integrally formed; they can be mechanically connected or electrically connected or able to communicate with each other; they can be the internal connection of two elements or the interaction relationship between two elements. Those skilled in the art can reasonably determine the specific meanings of the above words in the present invention in combination with the specific content of the technical solution.

[0021] Reference Figure 1 As shown, a car single RGB lamp bead atmosphere lamp driving system based on integrated LDO includes: The LDO module is connected to the vehicle voltage VBAT and is used to step down the vehicle voltage VBAT to a stable output voltage VDD; the LDO module includes a reference voltage module M1, a voltage divider module, an operational amplifier, a current clamp module M2 and a MOS tube Q1, the operational amplifier OP1 is used to compare the reference voltage generated by the reference voltage module M1 and the divided voltage generated by the voltage divider module to control the MOS tube Q1 to generate the output voltage VDD; the current clamp module M2 monitors the current flowing through the MOS tube Q1, and when the current reaches a set threshold, it can trigger a current clamp signal ILIMIT; RGB lamp beads, connected to the output voltage VDD; A driving module, the driving module comprising a PWM control module and a current digital-to-analog conversion module (IDAC); the PWM control module is used to generate a PWM modulation signal and control the duty cycle of the RGB lamp beads to adjust their brightness; the current digital-to-analog conversion module is connected to the RGB lamp beads, and dynamically adjusts the driving current of the RGB lamp bead module according to the PWM modulation signal; The logic control module is connected to the automobile ECU (electronic control unit) for communication, and is respectively connected to the LDO module and the drive module. The control module is used to receive the control signal of the automobile ECU and reduce the drive current according to the current clamp signal ILIMIT.

[0022] By setting up an LDO module and introducing the monitoring and control function of current clamping, this improvement not only improves the energy efficiency of the drive circuit, but also enhances the system's ability to accurately control the current, making it have more stable output characteristics under dynamic lighting environments.

[0023] Compared with traditional solutions, it has the following advantages: A new input current clamp monitoring function has been added: when the input current is clamped, the current clamp signal ILIMIT will be transmitted to the logic control module in real time. After receiving the signal, the logic control module will dynamically adjust the current digital-to-analog converter of the drive part to reduce the drive current and ensure that the system operates within a safe range.

[0024] Improved the current carrying capacity of the driving part: By optimizing the driving architecture, the current output capacity of the driving part is increased to meet the needs of high-brightness lighting, improve the luminous efficiency of RGB lamp beads, and enhance the overall visual performance of the vehicle atmosphere light.

[0025] It should be noted that, under the regulation of the PWM control module, the current digital-to-analog conversion module dynamically adjusts the driving current of the RGB lamp bead module according to the PWM modulation signal generated by the PWM control module. When the PWM duty cycle increases, the current digital-to-analog conversion module outputs a larger driving current to make the LED brighter; when the PWM duty cycle decreases, the current digital-to-analog conversion module reduces the output current and reduces the LED brightness. The current digital-to-analog conversion module can independently adjust the RGB three-color channels (LC1, LC2, LC3). The current digital-to-analog conversion module provides independent current control for each LED channel (red, green, and blue), ensuring that LEDs of different colors have precise driving currents to match the set color ratio and achieve rich color adjustment. When the LDO module detects overcurrent and triggers the current clamp signal ILIMIT, the current digital-to-analog conversion module will reduce the output current, reduce the LED load, and prevent the system from being damaged due to overcurrent. After receiving the current clamp signal ILIMIT, the logic control module will send an adjustment instruction to the current digital-to-analog conversion module to appropriately reduce the LED brightness to ensure the safe operation of the system.

[0026] Reference Figure 2 As shown, the drain of the MOS tube Q1 is connected to the input voltage VS, the source is connected to the output voltage VDD, and the gate is connected to the output end of the operational amplifier OP1; The reference voltage module M1 is respectively connected to the input voltage VS and the inverting input terminal of the operational amplifier OP1; The voltage divider module includes a first resistor R1 and a second resistor R2, the in-phase input end of the operational amplifier OP1 is connected between one end of each of the first resistor R1 and the second resistor R2, the other end of the first resistor R1 is connected to the source of the MOS transistor Q1, and the other end of the second resistor R2 is grounded; The input end of the current clamp module M2 is connected to the output end of the operational amplifier OP1, and the output end of the current clamp module M2 is connected to the logic control module.

[0027] It can be understood that the reference voltage module M1 generates a reference voltage and forms a comparison voltage through the resistor divider network R1 / R2. Subsequently, the operational amplifier OP1 performs operational control on the comparison voltage and the reference voltage to adjust the output voltage VDD of the MOS tube Q1 to ensure that it remains at a stable set value. At the same time, the system monitors the current changes on the MOS tube Q1 in real time. When the current flowing through the MOS tube Q1 reaches the upper limit value set by the current clamping module M2, the system immediately activates the current clamping mechanism to limit the output current within a safe range, and sends a current clamping signal ILIMIT to the logic control module through the ILIMIT bus, notifying the system that the current has reached the maximum value and cannot continue to increase. This mechanism can effectively prevent overcurrent risks and improve the safety and reliability of the system.

[0028] Reference Figure 3 As shown, the logic control module is connected to the vehicle ECU through the LIN physical layer. The LIN (Local Interconnect Network) bus is a low-cost, low-speed vehicle communication protocol widely used in body control systems. Among them, the LIN physical layer (LIN-PHY) is responsible for communicating with the vehicle ECU and transmitting control instructions to the logic control module, which further adjusts the drive part.

[0029] It can be understood that LIN-PHY is mainly responsible for the physical layer communication of the LIN bus, responsible for sending and receiving signals on the LIN bus, converting the LIN signal sent by the car ECU into a logic level signal recognizable inside the chip, and converting the control signal inside the chip into the LIN protocol format for transmission. The LIN bus uses a single-wire communication, the level is usually around 12V (vehicle battery voltage), and the chip usually works at a 5V or 3.3V logic level. LIN-PHY is responsible for converting the 12V LIN bus signal into a 5V (or 3.3V) digital signal for processing by the logic control module, and converting the chip's output signal back to the LIN physical level.

[0030] In addition, it also includes a diode and a filter capacitor, the vehicle voltage VBAT is connected to the positive electrode of the diode, the negative electrode of the diode is grounded through the filter capacitor, and an input voltage VS is formed between the negative electrode of the diode and the filter capacitor.

[0031] By integrating an LDO module inside the chip, the vehicle voltage VBAT is pre-stepped down, thereby effectively reducing the voltage drop loss and corresponding power consumption of the driving part. For example, when the output voltage VDD of the LDO module is set to 5V, the voltage drop of the driving part is only about 2V, while the voltage drop of the driving part of the traditional solution is usually as high as about 10V. In contrast, the present invention can reduce the power consumption of the driving part to about 1 / 5 of the original solution, significantly improving energy efficiency.

[0032] This optimized design not only reduces the energy loss of the driving part, but also improves its current driving capability, so that the system can provide a higher output current at the same input power. Although part of the power consumption is transferred from the driving part to the LDO module, it is still within a controllable range due to the thermal resistance and heat dissipation conditions of the chip package. Therefore, under the premise that the total input current remains unchanged, the present invention reduces the loss of the driving part, so that the driving current of a single channel can be improved. This improvement further enables the current of the 3-way driving part to be independently configured, achieving higher brightness output, and enhancing the dynamic adjustment capability of the RGB LED lamp beads, thereby improving the overall lighting effect.

[0033] Finally, it should be noted that the above specific implementation methods are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to examples, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the spirit and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A car single RGB lamp bead atmosphere lamp driving system based on integrated LDO, characterized in that: include: An LDO module is connected to the vehicle voltage and is used to step down the vehicle voltage to a stable output voltage; the LDO module includes a reference voltage module, a voltage divider module, an operational amplifier, a current clamp module and a MOS tube, and the operational amplifier is used to compare the reference voltage generated by the reference voltage module and the divided voltage generated by the voltage divider module to control the MOS tube to generate the output voltage; The current clamping module monitors the current flowing through the MOS tube, and when the current reaches a set threshold, it can trigger a current clamping signal; RGB lamp beads, connected to the output voltage; A driving module, the driving module comprising a PWM control module and a current digital-to-analog conversion module; The PWM control module is used to generate a PWM modulation signal and control the duty cycle of the RGB lamp beads to adjust their brightness; The current digital-to-analog conversion module is connected to the RGB lamp beads, and dynamically adjusts the driving current of the RGB lamp bead module according to the PWM modulation signal; The logic control module is connected to the automobile ECU for communication and is respectively connected to the LDO module and the drive module. The control module is used to receive the control signal of the automobile ECU and reduce the drive current according to the current clamp signal.

2. According to claim 1, a car single RGB lamp bead atmosphere lamp driving system based on integrated LDO is characterized in that: The drain of the MOS tube is connected to the input voltage, the source is connected to the output voltage, and the gate is connected to the output end of the operational amplifier; The reference voltage module is respectively connected to the input voltage and the inverting input terminal of the operational amplifier; The voltage divider module includes a first resistor and a second resistor, the in-phase input end of the operational amplifier is connected between one end of each of the first resistor and the second resistor, the other end of the first resistor is connected to the source of the MOS tube, and the other end of the second resistor is grounded; The input end of the current clamp module is connected to the output end of the operational amplifier, and the output end of the current clamp module is connected to the logic control module.

3. According to claim 1, a car single RGB lamp bead atmosphere lamp driving system based on integrated LDO is characterized in that: The output voltage is 5V.

4. According to claim 1, a car single RGB lamp bead atmosphere lamp driving system based on integrated LDO is characterized in that: The logic control module is connected to the automobile ECU through the LIN physical layer.

5. According to claim 1, a car single RGB lamp bead atmosphere lamp driving system based on integrated LDO is characterized in that: It also includes a diode and a filter capacitor, the vehicle-mounted voltage is connected to the positive electrode of the diode, the negative electrode of the diode is grounded through the filter capacitor, and an input voltage is formed between the negative electrode of the diode and the filter capacitor.

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