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 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 automotive cockpit atmosphere, and in particular to an automotive 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 the intelligent and personalized requirements of automobiles, in-vehicle atmosphere lamps are no longer limited to a single lighting function, but have gradually developed into an important interactive carrier to enhance the driving experience. Modern automotive atmosphere lamps not only play the role of ambient lighting, but also can create an immersive in-vehicle atmosphere through color transformation, dynamic effects and linkage with in-vehicle systems, enhancing driving pleasure and comfort. However, the current in-vehicle atmosphere lamp technology based on single lamp beads (such as RGB LEDs) still faces many technical bottlenecks in practical applications, which limit its visual performance and user experience in complex dynamic environments, and the specific manifestations are as follows:

[0003] Currently, the mainstream automotive single lamp bead atmosphere lamp solutions usually supply power by directly obtaining power from the automotive battery and delivering it to the LED lamp beads. However, there are large energy losses in the power supply process of this direct drive method, mainly due to the voltage drop loss of the drive circuit, resulting in low overall energy efficiency of the system. At the same time, due to the voltage fluctuation of the automotive battery, the direct power supply method has weak current control ability for LED lamp beads, which may lead to unstable brightness, thereby affecting the display consistency and dynamic adjustment effect of the atmosphere lamp. In addition, limited by the current driving ability, the existing solutions are difficult to achieve a balance between power consumption and thermal management under high brightness lighting requirements, affecting the service life of LED lamp beads. Summary of the Invention

[0004] Therefore, the present invention provides an automotive single RGB lamp bead atmosphere lamp driving system based on an integrated LDO. Through the design of the integrated LDO (low-dropout linear regulator), the voltage drop loss in the driving link is effectively reduced, thereby improving the current output ability of the drive circuit, and finally meeting the requirements of high brightness lighting.

[0005] To solve the above technical problems, the present invention provides an automotive single RGB lamp bead atmosphere lamp driving system based on an integrated LDO, including:

[0006] An LDO module, connected to the vehicle voltage and used to step down the vehicle voltage to a stable output voltage; the LDO module includes a reference voltage module, a voltage division module, an operational amplifier, a current clamping module, and a MOS transistor. The operational amplifier is used to compare the reference voltage generated by the reference voltage module and the divided voltage generated by the voltage division module to control the MOS transistor to generate the output voltage; the current clamping module monitors the current flowing through the MOS transistor, and when the current reaches a set threshold, it can trigger a current clamping signal.

[0007] An RGB light-emitting diode, connected to the output voltage;

[0008] A driving module, the driving module 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 light-emitting diode to adjust its brightness; the current digital-to-analog conversion module is connected to the RGB light-emitting diode and dynamically adjusts the driving current of the RGB light-emitting diode according to the PWM modulation signal.

[0009] A logic control module, communicatively connected to the vehicle ECU, and respectively connected to the LDO module and the driving module. The logic control module is used to receive the control signal of the vehicle ECU and reduce the driving current according to the current clamping signal.

[0010] In an embodiment of the present invention, the drain of the MOS transistor is connected to the input voltage, the source is connected to the output voltage, and the gate is connected to the output terminal of the operational amplifier;

[0011] The reference voltage module is respectively connected to the input voltage and the inverting input terminal of the operational amplifier;

[0012] The voltage division module includes a first resistor and a second resistor. The non-inverting input terminal of the operational amplifier is connected between one end of the first resistor and one end of the second resistor. The other end of the first resistor is connected to the source of the MOS transistor, and the other end of the second resistor is grounded;

[0013] The input terminal of the current clamping module is connected to the output terminal of the operational amplifier, and the output terminal of the current clamping module is connected to the logic control module.

[0014] In an embodiment of the present invention, the output voltage is 5V.

[0015] In an embodiment of the present invention, the logic control module is communicatively connected to the vehicle ECU through the LIN physical layer.

[0016] In an 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.

[0017] The above technical solution of the present invention has the following advantages compared with the prior art:

[0018] For a single RGB light bead atmosphere light driving system for automobiles based on an integrated LDO of the present invention, through the design of the 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 meeting the requirement of high-brightness lighting. In addition, it also has the following advantages:

[0019] By reducing the voltage drop in the driving part, the present invention improves its current output capacity, enabling the system to provide a higher output current under the same input power. With the total input current remaining unchanged, the system can support a higher brightness output and improve the luminous efficiency of the RGB LED, thereby enhancing the overall visual performance.

[0020] The present invention sets a current clamping module for real-time monitoring of the current flowing through the MOS transistor, and triggering a current clamping signal when the set threshold is exceeded to limit the output current. This process can effectively prevent system failures caused by overload or abnormal conditions, improving the safety and reliability of the system. Solving the problem of the lack of precise current management in the traditional solution, the current clamping mechanism of the present invention ensures that the LED load will not be damaged due to overcurrent, improving the stability of the vehicle-mounted atmosphere light system.

[0021] 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, reducing the LED brightness and power consumption. By adjusting the current digital-to-analog conversion module, further optimizing the LED color performance to maintain color consistency at different brightness levels. The traditional LED brightness control mainly relies on PWM (pulse width modulation), but in the low brightness state, the PWM duty cycle is small, which may cause LED flickering or uneven brightness.

[0022] The logic control module of the present invention communicates with the vehicle ECU through the LIN physical layer to achieve intelligent control, and reduces the system complexity and cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to make the content of the present invention easier to be clearly understood, the present invention will be further described in detail below according to the specific embodiments of the present invention in conjunction with the drawings.

[0024] Figure 1This is the schematic diagram of the automotive single RGB lamp bead ambient light driving system integrating the LDO of the present invention.

[0025] Figure 2 This is the schematic diagram of the LDO module with current clamping function of the present invention.

[0026] Figure 3 This is the schematic diagram of the driving part of the present invention. Specific Embodiments

[0027] The present invention will be 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 be able to implement it, but the specific embodiments cited do not limit the present invention.

[0028] In the present invention, when 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, rather than indicating or implying that the technical features referred to must have a specific orientation, be constructed and operated in a specific orientation, so it cannot be understood as a limitation to the present invention.

[0029] In the present invention, the meaning of "several" is one or more, the meaning of "multiple" is two or more, and "greater than", "less than", "exceeding", etc. are understood as not including the present number; "above", "below", "within", etc. are understood as including the present number. In the description of the present invention, if "first" and "second" are described, they are only used for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features or implicitly indicating the sequence relationship of the indicated technical features.

[0030] In the present invention, unless otherwise clearly defined, words such as "set", "installed", "connected", etc. 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, and can also be integrally formed; they can be mechanically connected, electrically connected or capable of communicating with each other; they can be the communication inside two components or the interaction relationship between two components. Those skilled in the art can reasonably determine the specific meaning of the above words in the present invention in combination with the specific content of the technical solution.

[0031] Refer to Figure 1 As shown, an automotive single RGB lamp bead ambient light driving system based on an integrated LDO includes:

[0032] The LDO module is connected to the vehicle-mounted voltage VBAT and is used to step down the vehicle-mounted voltage VBAT to a stable output voltage VDD. The LDO module includes a reference voltage module M1, a voltage division module, an operational amplifier, a current clamping module M2, and a MOS transistor 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 division module to control the MOS transistor Q1 to generate the output voltage VDD. The current clamping module M2 monitors the current flowing through the MOS transistor Q1, and when the current reaches a set threshold, it can trigger a current clamping signal ILIMIT.

[0033] The RGB light-emitting diode is connected to the output voltage VDD.

[0034] The driving module includes 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 light-emitting diode to adjust its brightness. The current digital-to-analog conversion module is connected to the RGB light-emitting diode and dynamically adjusts the driving current of the RGB light-emitting diode according to the PWM modulation signal.

[0035] The logic control module is communicatively connected to the vehicle's ECU (Electronic Control Unit) and is respectively connected to the LDO module and the driving module. The logic control module is used to receive the control signal from the vehicle's ECU and reduce the driving current according to the current clamping signal ILIMIT.

[0036] By setting up the LDO module and introducing the monitoring and control function of current clamping. This improvement not only enhances the energy efficiency of the driving circuit but also strengthens the system's precise current control ability, enabling it to have more stable output characteristics in a dynamic lighting environment.

[0037] Compared with the traditional solution, it has the following advantages:

[0038] A new monitoring function for input current clamping is added: when the input current is clamped, the current clamping signal ILIMIT will be transmitted to the logic control module in real time. After receiving the signal, the latter will dynamically adjust the current digital-to-analog converter in the driving part to reduce the driving current and ensure that the system operates within a safe range.

[0039] The current-carrying capacity of the driving part is improved: by optimizing the driving architecture, increasing the current output capacity of the driving part to meet the high-brightness lighting requirements, improving the luminous efficiency of the RGB light-emitting diode, and enhancing the overall visual performance of the vehicle-mounted atmosphere light.

[0040] It should be noted that under the regulation of the PWM control module, the current digital-to-analog conversion module dynamically adjusts the drive current of the RGB LED 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 drive current, making the LED brighter; when the PWM duty cycle decreases, the current digital-to-analog conversion module reduces the output current and decreases the LED brightness. The current digital-to-analog conversion module can independently adjust the current of the RGB three-color channels (LC1, LC2, LC3). The current digital-to-analog conversion module provides independent current control for each LED channel to ensure that different-color LEDs have accurate drive currents to match the set color ratio and achieve rich color adjustment. When the LDO module detects overcurrent and triggers the current clamping signal ILIMIT, the current digital-to-analog conversion module will reduce the output current, lower the LED load, and prevent the system from being damaged due to overcurrent. After receiving the current clamping signal ILIMIT, the logic control module sends an adjustment instruction to the current digital-to-analog conversion module to appropriately reduce the LED brightness and ensure the safe operation of the system.

[0041] Referring to Figure 2 As shown, the drain of the MOS transistor 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 terminal of the operational amplifier OP1;

[0042] The reference voltage module M1 is respectively connected to the input voltage VS and the inverting input terminal of the operational amplifier OP1;

[0043] The voltage division module includes a first resistor R1 and a second resistor R2. The non-inverting input terminal 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;

[0044] The input terminal of the current clamping module M2 is connected to the output terminal of the operational amplifier OP1, and the output terminal of the current clamping module M2 is connected to the logic control module.

[0045] It can be understood that the reference voltage module M1 generates a reference voltage, and forms a comparison voltage through the resistor voltage division network R1 / R2. Subsequently, the operational amplifier OP1 performs arithmetic control on the comparison voltage and the reference voltage to adjust the output voltage VDD of the MOS transistor Q1 to ensure that it is maintained at a stable set value. At the same time, the system will monitor the current change on the MOS transistor Q1 in real time. When the current flowing through the MOS transistor Q1 reaches the upper limit value set by the current clamping module M2, the system will immediately activate the current clamping mechanism to limit the output current within a safe range, and send a current clamping signal ILIMIT to the logic control module through the ILIMIT bus to notify the system that the current has reached the maximum value and cannot continue to increase. This mechanism can effectively prevent the risk of overcurrent and improve the safety and reliability of the system.

[0046] Refer to Figure 3 As shown, the logic control module is communicatively connected to the automotive ECU through the LIN physical layer. The LIN (Local Interconnect Network) bus is a low-cost, low-rate in-vehicle communication protocol widely used in body control systems. Among them, the LIN physical layer (LIN-PHY) is responsible for communicating with the automotive ECU and transmitting control instructions to the logic control module, which further adjusts the drive part.

[0047] It can be understood that the 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 signals sent by the automotive ECU into logic level signals recognizable inside the chip, and converting the control signals inside the chip into the LIN protocol format for sending. The LIN bus uses single-wire communication, and the voltage is usually around 12V (vehicle battery voltage), while the inside of the chip usually operates at 5V or 3.3V logic levels. The LIN-PHY is responsible for converting the 12V LIN bus signal into a 5V (or 3.3V) digital signal for the logic control module to process, and converting the output signal of the chip back to the LIN physical level.

[0048] In addition, it also includes a diode and a filter capacitor. The vehicle-mounted voltage VBAT is connected to the positive electrode of the diode, and the negative electrode of the diode is grounded through the filter capacitor. An input voltage VS is formed between the negative electrode of the diode and the filter capacitor.

[0049] By integrating an LDO module inside the chip to pre-step down the in-vehicle voltage VBAT, the voltage drop loss and corresponding power consumption of the driving part can be effectively reduced. 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 in 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 the energy efficiency.

[0050] This optimized design not only reduces the energy loss of the driving part, but also improves its current driving ability, enabling the system to 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, limited by the thermal resistance and heat dissipation conditions of the chip package, the power consumption still remains within a controllable range. Therefore, on the premise that the total input current remains unchanged, the present invention increases the driving current of a single channel by reducing the loss of the driving part. This improvement further enables the currents of the three driving parts to be independently configured, achieving a higher brightness output and enhancing the dynamic adjustment ability of the RGB LED beads, thereby improving the overall lighting effect.

[0051] Finally, it should be noted that the above specific embodiments are only used to illustrate the technical solutions of the present invention and are not restrictive. Although the present invention has been described in detail with reference to the examples, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within 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 beads 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 driving module. The logic control module is used to receive the control signal of the automobile ECU and reduce the driving current according to the current clamping 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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