BUCK chip output voltage regulation control device

Abstract

The utility model provides a BUCK chip output voltage regulation control device, and belongs to the technical field of automobile lighting. The control device comprises a BUCK chip, a resistance voltage divider, a PWM (Pulse Width Modulation) control circuit and an MCU (Microprogrammed Control Unit) microcontroller, an output end of the MCU microcontroller is electrically connected with an input end of the PWM control circuit, an output end of the PWM control circuit is electrically connected with an input end of the resistance voltage divider, an output end of the resistance voltage divider is electrically connected with an FB pin of the BUCK chip, a VOUT pin of the BUCK chip is externally connected with an LED load, and the BUCK chip is used for dynamically adjusting a voltage value output to the LED load. The BUCK chip can output different output voltages without replacing a resistor, and does not need to add a plurality of BUCK chips to output different voltages, so that design redundancy is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of vehicle lamp lighting, in particular to a BUCK chip output voltage regulation control device. Background Art

[0002] In the prior art, to adapt the buck chip's output voltage to meet the fluctuating demands of the automotive lighting market, the desired buck chip output voltage is set by changing the feedback ratio of the buck chip's feedback pin or adjusting the chip's internal reference voltage. The former involves adjusting the output voltage by adjusting the feedback ratio of an external resistor divider, while the latter involves programming the chip's internal reference voltage. Due to the varying number of LEDs connected in series at the lamp end, the required supply voltage for the controller varies. To ensure the required voltage at the lamp end, the buck chip's output voltage can be set by adjusting the feedback ratio of the chip pin. However, adjusting the feedback ratio requires changing the value of the external divider resistor. This requires changing the resistors on the driver board, and when different output voltages are required, the resistors must be adjusted. This not only poses significant challenges to production requirements, but also makes it difficult to achieve a precise feedback ratio and poses challenges to circuit stability.

[0003] The above problems need to be solved. Utility Model Content

[0004] To address at least one technical problem in the prior art, an embodiment of the present invention provides a buck chip output voltage regulation control device, comprising: a buck chip, a resistor voltage divider, a PWM control circuit, and an MCU microcontroller; the output of the MCU microcontroller is electrically connected to the input of the PWM control circuit, the output of the PWM control circuit is electrically connected to the input of the resistor voltage divider, the output of the resistor voltage divider is electrically connected to the FB pin of the buck chip, the VOUT pin of the buck chip is externally connected to an LED load, and the buck chip is configured to dynamically adjust the voltage output to the LED load.

[0005] Furthermore, the MCU microcontroller is used to automatically adjust the duty cycle to set DC voltage signals of different gears based on the preset resistance value of the resistor divider.

[0006] Furthermore, a PWM signal generator is integrated in the MCU microcontroller, and the PWM signal generated by the PWM signal generator is sent out through the PWM resource port of the MCU microcontroller.

[0007] Furthermore, the device also includes an RC filter circuit, the input end of the RC filter circuit is electrically connected to the output end of the MCU microcontroller, and the output end of the RC filter circuit is electrically connected to the input end of the PWM control circuit, for converting the PWM signal emitted by the MCU microcontroller into a DC analog voltage signal.

[0008] Furthermore, the RC filter circuit includes a sixth resistor R6, a seventh resistor R7, a first capacitor C1 and a second capacitor C2. The left side of the sixth resistor R6 is connected to the PWM signal emitted by the MCU microcontroller, and the right side is connected to the left side of the seventh resistor R7. The right side of the seventh resistor R7 is used as the DC output side output voltage feedback signal VFB. One side of the first capacitor C1 is grounded, and the other side is connected between the sixth resistor R6 and the seventh resistor R7. One side of the second capacitor C2 is grounded, and the other side is connected to the right side of the seventh resistor R7.

[0009] Furthermore, the PWM control circuit is used to control the output power of the circuit by adjusting the pulse width, thereby changing the feedback ratio of the resistor divider.

[0010] Furthermore, the PWM control circuit includes an NMOS transistor Q2, a third resistor R3 and a fourth resistor R4. The source S of the NMOS transistor Q2 is grounded, the drain D outputs a voltage feedback signal VFB, the gate G is connected to the left side of the fourth resistor R4, and the right side of the fourth resistor R4 is connected to the PWM signal. One end of the third resistor is grounded, and the other end is connected between the NMOS transistor Q2 and the fourth resistor R4.

[0011] Furthermore, the resistor divider is used to dynamically adjust the voltage value output by the VOUT pin of the BUCK chip based on the change of the feedback ratio.

[0012] Furthermore, the resistor divider includes a pull-up resistor R1 and a pull-down resistor R2. One end of the pull-down resistor R2 is grounded, and the other end is connected to one end of the pull-up resistor R1. The other end of the pull-up resistor R1 is connected to the output end of the VOUT pin of the BUCK chip.

[0013] Furthermore, the BUCK chip model is LN10046FSQ1LQR, the MCU microcontroller model is FS32K144HAT0MLHT, and the LED load includes an LED lamp.

[0014] The technical solution provided by the present invention provides the following beneficial effects: by connecting a PWM control circuit to the input of a resistor divider, the PWM control circuit primarily adjusts the feedback ratio of the chip's external resistor divider to set the output voltage of VOUT, enabling the output of different desired voltage values within a certain range. Furthermore, by dynamically adjusting the feedback ratio, a high-precision voltage value can be output. Furthermore, due to the simple structure of the PWM control circuit, there is no need to consider multiple circuit designs, thus reducing the cost of the entire design solution. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 The present invention provides a schematic diagram of the structure of a BUCK chip output voltage regulation control device.

[0017] Figure 2 This is a topological diagram of a PWM control circuit provided by an embodiment of the present utility model.

[0018] Figure 3 This is a topology diagram of an RC filter circuit provided by an embodiment of the utility model. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solutions and advantages of the present invention more clear, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which this invention pertains; the terms used in this specification are for the purpose of describing specific embodiments only and are not intended to limit this invention; for example, the directions or positions indicated by the terms "length", "width", "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", "upper end", "lower end", "middle", etc. are based on the directions or positions shown in the accompanying drawings and are for ease of description only and should not be construed as limiting this technical solution.

[0021] The terms "including," "having," and any variations thereof in the specification and claims of this utility model and the accompanying drawings are intended to cover non-exclusive inclusions. The terms "first," "second," and the like in the specification and claims of this utility model and the accompanying drawings are used to distinguish between different items, not to describe a particular order. "Multiple" means two or more, unless otherwise expressly specified.

[0022] Furthermore, references to "embodiments" herein mean that a particular feature, structure, or characteristic described in connection with the embodiments may be included in at least one embodiment of the present invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments. It is understood, both explicitly and implicitly, by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0023] Example

[0024] like Figure 1 FIG2 is a schematic structural diagram of a BUCK chip output voltage regulation control device provided by an embodiment of the present invention.

[0025] To facilitate subsequent understanding, the working principle of the utility model is explained: the utility model is mainly composed of a BUCK chip and peripheral circuits, and the peripheral circuits include a PWM control circuit, a PWM signal generator, a resistor divider, and a lamp load. The utility model makes up for the deficiency of some BUCK chips that cannot adjust the output voltage, reduces the number of circuit components, and optimizes cost pressure. Specifically, the BUCK chip is mainly used to reduce the input voltage to the constant voltage we need through a buck topology. Different voltage values can be set for VOUT through an external feedback ratio resistor divider. The PWM control circuit is mainly used to change the feedback ratio of the chip's external resistor divider to set the output voltage of VOUT.

[0026] As an example, the control device includes: a buck chip 100, a resistor divider 110, a PWM control circuit 120, and an MCU microcontroller 130; the output end of the MCU microcontroller 130 is electrically connected to the input end of the PWM control circuit 120, the output end of the PWM control circuit 120 is electrically connected to the input end of the resistor divider 110, the output end of the resistor divider 110 is electrically connected to the FB pin of the buck chip 100, the VOUT pin of the buck chip 100 is externally connected to an LED load, and the buck chip 100 is used to dynamically adjust the voltage value output to the LED load 140.

[0027] Preferably, the MCU microcontroller 130 is configured to automatically adjust the duty cycle based on the preset resistance value of the resistor divider to set different DC voltage signal levels. Specifically, the MCU microcontroller 130 is integrated with a PWM signal generator, which generates a PWM signal that is transmitted via the PWM resource port of the MCU microcontroller 130. The PWM signal voltage frequency is preferably 20 kHz. When the PWM signal is converted into a DC analog voltage via the RC filter circuit 150, the maximum allowable ripple voltage is + / -100 mV. To ensure output voltage stability, the voltage ratio adjustment range is typically set to 10%-80%. More specifically, the preset resistance value of the resistor divider can be set based on the LED string of the lamp as a reference. A white light bulb has a voltage drop of approximately 3V and is typically used as an LED power supply. The output voltage is generally 3V (for one LED) or 6V (for a string of two LEDs). Considering the voltage drop losses of other components, the maximum output voltage is generally set to 8V, and the minimum output voltage is 3V, so the confirmed output voltage range is 3V-8V. Each chip VFB has a reference voltage inside. You can check the chip's data sheet or ask the chip manufacturer. In order to meet most voltage requirements on the market, the reference voltage of VF is generally around 1V. According to the required maximum output voltage of 8V, the resistor value of the voltage divider is set to reduce the static power consumption of the entire circuit. The resistance value of the feedback ratio is generally set at the kiloohm level. Among them, the MCU microcontroller 130 model is FS32K144HAT0MLHT. It should be noted that the model of the MCU microcontroller 130 is not restricted here. Relevant technicians can change the model of the MCU microcontroller 130 based on actual needs during the actual design process.

[0028] Preferably, the device further includes an RC filter circuit 150, the input end of the RC filter circuit 150 being electrically connected to the output end of the MCU microcontroller 130, and the output end of the RC filter circuit 150 being electrically connected to the input end of the PWM control circuit 120, for converting the PWM signal sent by the MCU microcontroller 130 into a DC analog voltage signal. Specifically, Figure 3 As shown, the RC filter circuit 150 includes a sixth resistor R6, a seventh resistor R7, a first capacitor C1 and a second capacitor C2. The left side of the sixth resistor R6 is connected to the PWM signal emitted by the MCU microcontroller 130, and the right side is connected to the left side of the seventh resistor R7. The right side of the seventh resistor R7 is used as the DC output side output voltage feedback signal VFB. One side of the first capacitor C1 is grounded, and the other side is connected between the sixth resistor R6 and the seventh resistor R7. One side of the second capacitor C2 is grounded, and the other side is connected to the right side of the seventh resistor R7.

[0029] Preferably, the PWM control circuit 120 is used to control the output power of the circuit by adjusting the pulse width and thereby changing the feedback ratio of the resistor divider. Figure 2 As shown, the PWM control circuit 120 includes an NMOS transistor Q2, a third resistor R3, and a fourth resistor R4. The source S of the NMOS transistor Q2 is grounded, the drain D outputs a voltage feedback signal VFB, the gate G is connected to the left side of the fourth resistor R4, and the right side of the fourth resistor R4 receives the PWM signal. One end of the third resistor is grounded, and the other end is connected between the NMOS transistor Q2 and the fourth resistor R4. The NMOS transistor Q2 receives a high-frequency PWM signal, and different duty cycle values can change the feedback ratio. The third resistor R3 serves as a protection circuit for the NMOS transistor, and the fourth resistor R4 is used to stabilize the PWM signal.

[0030] Preferably, the resistor divider 110 is used to dynamically adjust the voltage value output by the VOUT pin of the BUCK chip 100 based on the change of the feedback ratio. Figure 2 As shown, the resistor divider 110 includes a pull-up resistor R1 and a pull-down resistor R2. One end of the pull-down resistor R2 is grounded, and the other end is connected to one end of the pull-up resistor R1. The other end of the pull-up resistor R1 is connected to the output end of the VOUT pin of the BUCK chip 100. The model of the BUCK chip 100 is LN10046FSQ1LQR. It should be noted that the model of the BUCK chip 100 is not specifically limited here, and relevant technicians can change the model of the BUCK chip 100 based on actual needs during the design process.

[0031] Preferably, the LED load 150 includes an LED lamp.

[0032] The BUCK chip in the above embodiment can output different output voltages without replacing resistors; there is no need to add multiple BUCK chips to output different voltages, reducing design redundancy; the added PWM modulation circuit is relatively simple, low-cost, and stable in design.

[0033] The above is only an embodiment of the present utility model. Common knowledge such as the known specific structures and characteristics in the scheme is not described in detail here. Ordinary technicians in the relevant field are aware of all common technical knowledge in the technical field of the utility model before the application date or priority date, can obtain all existing technologies in the field, and have the ability to apply conventional experimental means before that date. Ordinary technicians in the relevant field can improve and implement this scheme in combination with their own abilities under the inspiration given by this application. Some typical known structures or known methods should not become obstacles for ordinary technicians in the relevant field to implement this application. It should be pointed out that for technicians in this field, without departing from the structure of the utility model, several deformations and improvements can be made, which should also be regarded as the scope of protection of the utility model. These will not affect the effect of the implementation of the utility model and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A BUCK chip output voltage regulation control device, characterized in that: The control device includes: a BUCK chip, a resistor voltage divider, a PWM control circuit and an MCU microcontroller; The output end of the MCU microcontroller is electrically connected to the input end of the PWM control circuit, the output end of the PWM control circuit is electrically connected to the input end of the resistor divider, the output end of the resistor divider is electrically connected to the FB pin of the BUCK chip, the VOUT pin of the BUCK chip is externally connected to an LED load, and the BUCK chip is used to dynamically adjust the voltage value output to the LED load.

2. The BUCK chip output voltage regulation control device according to claim 1, characterized in that: The MCU microcontroller is used to automatically adjust the duty cycle based on the preset resistance value of the resistor divider to set the DC voltage signal of different gears.

3. The BUCK chip output voltage regulation control device according to claim 2, characterized in that: The MCU microcontroller is integrated with a PWM signal generator, and the PWM signal generated by the PWM signal generator is sent out through the PWM resource port of the MCU microcontroller.

4. The BUCK chip output voltage regulation control device according to claim 1, characterized in that: The device also includes an RC filter circuit, the input end of the RC filter circuit is electrically connected to the output end of the MCU microcontroller, and the output end of the RC filter circuit is electrically connected to the input end of the PWM control circuit, for converting the PWM signal emitted by the MCU microcontroller into a DC analog voltage signal.

5. The BUCK chip output voltage regulation control device according to claim 4, characterized in that: The RC filter circuit includes a sixth resistor R6, a seventh resistor R7, a first capacitor C1 and a second capacitor C2. The left side of the sixth resistor R6 is connected to the PWM signal emitted by the MCU microcontroller, and the right side is connected to the left side of the seventh resistor R7. The right side of the seventh resistor R7 is used as the DC output side output voltage feedback signal VFB. One side of the first capacitor C1 is grounded, and the other side is connected between the sixth resistor R6 and the seventh resistor R7. One side of the second capacitor C2 is grounded, and the other side is connected to the right side of the seventh resistor R7.

6. The BUCK chip output voltage regulation control device according to claim 1, characterized in that: The PWM control circuit is used to control the output power of the circuit by adjusting the pulse width, thereby changing the feedback ratio of the resistor divider.

7. The BUCK chip output voltage regulation control device according to claim 6, characterized in that: The PWM control circuit includes an NMOS transistor Q2, a third resistor R3, and a fourth resistor R4. The source S of the NMOS transistor Q2 is grounded, the drain D outputs a voltage feedback signal VFB, the gate G is connected to the left side of the fourth resistor R4, and the right side of the fourth resistor R4 is connected to the PWM signal. One end of the third resistor is grounded, and the other end is connected between the NMOS transistor Q2 and the fourth resistor R4.

8. The BUCK chip output voltage regulation control device according to claim 1, characterized in that: The resistor divider is used to dynamically adjust the voltage value output by the VOUT pin of the BUCK chip based on the change of the feedback ratio.

9. The BUCK chip output voltage regulation control device according to claim 8, characterized in that: The resistor divider includes a pull-up resistor R1 and a pull-down resistor R2. One end of the pull-down resistor R2 is grounded, and the other end is connected to one end of the pull-up resistor R1. The other end of the pull-up resistor R1 is connected to the output end of the VOUT pin of the BUCK chip.

10. The BUCK chip output voltage regulation control device according to claim 1, characterized in that: The BUCK chip model is LN10046FSQ1LQR, the MCU microcontroller model is FS32K144HAT0MLHT, and the LED load includes an LED lamp.

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