Circuit topology capable of realizing RCOT modulation and adaptive buck-boost and automobile lamp
By using RCOT modulation and an adaptive buck-boost circuit topology, the problem of inconsistent output voltage caused by LED light strings in different car models is solved, realizing an efficient and simple adaptive buck-boost function, and improving circuit efficiency and dynamic response speed.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUANGZHOU JUSHUO BOAN TECHNOLOGY CO LTD
- Filing Date
- 2026-03-24
- Publication Date
- 2026-07-10
AI Technical Summary
In existing technologies, the number of LED light strings varies for different car models, resulting in inconsistent output voltage of the control circuit. Existing solutions are inefficient, complex, and lack dynamic response, which can easily lead to overheating or short circuits.
The circuit topology employs RCOT modulation and adaptive buck-boost, and achieves adaptive buck-boost functionality through a combination of switching transistors and a drive controller. Combined with voltage acquisition and comparison circuits and dynamic response circuits, it dynamically switches between boost and buck circuit architectures to improve efficiency and response speed.
It achieves efficient and simple adaptive buck-boost function, improves circuit efficiency, avoids circuit overheating and short circuit problems, and enhances dynamic response speed.
Smart Images
Figure CN122371685A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of electronic circuit technology, specifically relating to a circuit topology that enables RCOT modulation and adaptive buck-boost voltage, and an automotive lamp. Background Technology
[0002] In the field of automotive electronic headlights, as well as in other aspects of social life, a single headlight control board controls different LED light strings for different car models. The number of lights is not fixed, so the output voltage of the control circuit is also not fixed, ranging from 3V to 60V. The voltage of the car battery system is 12V / 24V, and for the car electrical system, the voltage range is between 9V and 36V. In other words, for the design requirements of the headlight drive module, the output voltage may be higher or lower than the input voltage.
[0003] There are currently two solutions. The first solution is as follows: Figure 1 As shown, a topology is used. The LED electrode is forcibly connected to... Up, in this way, The actual required voltage value, at this time, Always greater than This forcibly transforms the demand into a constant boost demand. Existing technologies commonly used in this area include Maxim Integrated's MAX16833 and SG Micro's SGM3775, both of which employ this architecture. This solution has the following significant drawbacks:
[0004] (1) By forcibly transforming the buck-boost circuit into a boost circuit, efficiency is greatly reduced. For a circuit whose actual requirement is boost, if the output current is 2A, then... All of the power is dissipated power, which is reactive power. If the battery is a 12V system, then about 24W of power will definitely not generate efficiency. The efficiency of the entire circuit is too low and the heat generation is too severe.
[0005] (2) If a SAM controller needs to be connected, the LED is already connected to the system ground, and on the LED driver circuit board side, the LED is connected to... Connected, at this time systematically with The circuit short-circuited and burned out when the two circuits were connected.
[0006] The second option, such as Figure 2As shown, the SEPIC architecture, compared to the first scheme, adds a large capacitor Cc and a large inductor L2. These two devices, as energy storage components, occupy a significant area. Furthermore, the parameter calculation, selection, and debugging of these two devices are quite challenging for hardware engineers. This scheme results in a large current flowing through the capacitor in the main circuit loop, requiring the design of compensation circuits to ensure system stability. However, both type II and type III compensation circuits not only increase circuit complexity but also pose a considerable challenge for hardware engineers.
[0007] In addition, in the field of automotive electrical systems, situations such as load dumping often occur, which can cause the car battery voltage to rise or fall suddenly. In such cases, the car's control circuit board needs to have a very strong dynamic response speed. Otherwise, there may be situations where the voltage drops suddenly, causing the output voltage to drop and the lights to turn off momentarily, or the voltage is too high and the circuit's dynamic response is insufficient, resulting in excessively high output voltage and damage to the circuit board. Summary of the Invention
[0008] This invention addresses the technical problem of the aforementioned defects in two existing solutions when different vehicle models use different LED light strings, resulting in inconsistent output voltage of the control circuit. The purpose is to provide a circuit topology and automotive light that can achieve RCOT modulation and adaptive buck-boost.
[0009] To address the aforementioned technical problems, a first aspect of the present invention provides a circuit topology capable of realizing RCOT modulation and adaptive buck-boost, the circuit topology comprising a power supply terminal and a load, wherein the negative terminal of the load is grounded, and the circuit topology further comprising:
[0010] The first switching transistor has its drain connected to the power supply terminal and its source connected to one end of an inductor.
[0011] The second switch has its drain connected to the source of the first switch, and its source is grounded.
[0012] The third switching transistor has its drain connected to the other end of the inductor and its source grounded.
[0013] A fourth switching transistor, the drain of which is connected to the other end of the inductor, and the source of which is connected to the positive terminal of the load;
[0014] A filter capacitor, wherein the filter capacitor is connected in parallel with the load;
[0015] A buck drive controller, wherein the buck drive controller is connected to the gate of the first switch and the gate of the second switch respectively;
[0016] A boost drive controller is connected to the gate of the third switch and the gate of the fourth switch, respectively.
[0017] Optionally, in the circuit topology that enables RCOT modulation and adaptive buck-boost as described above, the first switch, the second switch, the third switch, and the fourth switch are NMOS transistors.
[0018] Optionally, in the circuit topology that enables RCOT modulation and adaptive buck-boost as described above, the first switch, the second switch, the third switch, and the fourth switch are enhancement-mode NMOS transistors.
[0019] Optionally, in the circuit topology that enables RCOT modulation and adaptive buck-boost as described above, the load is an LED lamp.
[0020] Optionally, in the circuit topology that enables RCOT modulation and adaptive buck-boost as described above, after the circuit topology is powered on, the voltage at the power supply terminal is collected as the input voltage, and the voltage of the load is collected as the output voltage.
[0021] When the input voltage is less than the output voltage, the buck driver controller controls the first switch to always be on and the second switch to always be off, forming a boost circuit architecture. The boost driver controller controls the third and fourth switches to be on or off to control the operating state of the circuit topology.
[0022] When the input voltage is greater than the output voltage, the boost drive controller controls the fourth switch to always be on and the third switch to always be off. The circuit topology forms a buck circuit architecture. The buck drive controller controls the first and second switches to be on or off to control the operating state of the circuit topology.
[0023] Optionally, in the circuit topology that enables RCOT modulation and adaptive buck-boost as described above, the circuit topology further includes a voltage acquisition and comparison circuit, which includes:
[0024] A first input-side sampling resistor, one end of which is connected to the power supply terminal;
[0025] A second input-side sampling resistor, one end of which is connected to the other end of the first input-side sampling resistor, and the other end of which is grounded;
[0026] A first output-side sampling resistor, one end of which is connected to the positive terminal of the load;
[0027] The second output-side sampling resistor has one end connected to the other end of the first output-side sampling resistor, and the other end of the second output-side sampling resistor is grounded.
[0028] A first comparator has one input terminal connected to the common terminal between the first output-side sampling resistor and the second output-side sampling resistor, and another input terminal connected to the common terminal between the first input-side sampling resistor and the second input-side sampling resistor. The output terminal of the first comparator is connected to the boost drive controller.
[0029] The third comparator has one input terminal connected to the common terminal between the first input-side sampling resistor and the second input-side sampling resistor, and the other input terminal connected to the common terminal between the first output-side sampling resistor and the second output-side sampling resistor. The output terminal of the third comparator is connected to the buck drive controller.
[0030] Optionally, in the circuit topology that enables RCOT modulation and adaptive buck-boost as described above, the circuit topology further includes a dynamic response circuit, which includes:
[0031] Triggers, which are respectively connected to the buck drive controller and the boost drive controller;
[0032] The second comparator has one input terminal connected to the common terminal between the first output sampling resistor and the second output sampling resistor, another input terminal connected to a preset reference voltage, and an output terminal connected to the set terminal of the flip-flop.
[0033] A timer, which is connected to the trigger.
[0034] Optionally, in the circuit topology that enables RCOT modulation and adaptive buck-boost as described above, when the voltage at the common terminal between the first output-side sampling resistor and the second output-side sampling resistor is less than the reference voltage, the second comparator flips, setting the trigger and driving the buck drive controller and the boost drive controller to partially turn on the first, second, third, and fourth switches, causing the inductor current to rise until the timer overflows. The trigger then resets, driving the buck drive controller and the boost drive controller to change the states of the first, second, third, and fourth switches, causing the inductor current to decrease.
[0035] To address the aforementioned technical problems, a second aspect of the present invention provides an automotive lamp, characterized in that the automotive lamp has the circuit topology provided in the first aspect of the present invention, which enables RCOT modulation and adaptive buck-boost.
[0036] The positive and progressive effects of this invention are as follows:
[0037] 1. This invention can realize adaptive buck-boost function, and the debugging is very simple for hardware engineers.
[0038] 2. This invention can determine whether the circuit is switched to a boost circuit architecture or a buck circuit architecture by comparing the input side voltage, the load side voltage and each reference voltage.
[0039] 3. This invention solves the problem of insufficient dynamic response in the prior art through RCOT control.
[0040] 4. The efficiency of the circuit topology of this invention is far higher than that of the prior art. Figure 1 The efficiency of the topology structure is such that it does not cause the circuit to overheat. Furthermore, this invention solves... Figure 1 This could lead to short circuit problems in the topology. Attached Figure Description
[0041] The disclosure of this invention will become more apparent from the accompanying drawings. It should be understood that these drawings are for illustrative purposes only and are not intended to limit the scope of protection of this invention. In the drawings:
[0042] Figure 1 This is a circuit diagram showing the topology used in the first solution of the prior art.
[0043] Figure 2 This is a circuit diagram of the second solution in the prior art that uses the SEPIC architecture;
[0044] Figure 3This is a basic circuit diagram of a boost circuit in the prior art;
[0045] Figure 4 This is a basic circuit diagram of a buck circuit in the prior art;
[0046] Figure 5 This is a circuit diagram of the present invention. Detailed Implementation
[0047] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.
[0048] It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other.
[0049] In the description of this invention, it should be noted that the directional terms such as "outer side", "middle section", "inner", "outer" indicate the orientation and positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. They should not be construed as limiting the specific protection scope of this invention.
[0050] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features. Thus, the use of "first" and "second" to define a feature may explicitly or implicitly include one or more of that feature. In the description of this invention, "several" or "a number" means two or more, unless otherwise explicitly specified.
[0051] Reference Figure 5 This invention provides a circuit topology capable of RCOT modulation and adaptive buck-boost, comprising a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, an inductor L, a filter capacitor C, and a load R. L Buck driver control U1 and boost driver control U2.
[0052] The drain of the first switching transistor S1 is connected to the power supply terminal Vin, the source of the first switching transistor S1 is connected to one end of the inductor L, and the gate of the first switching transistor S1 is connected to the buck drive controller U1.
[0053] The drain of the second switch S2 is connected to the source of the first switch S1, the source of the second switch S2 is grounded, and the gate of the second switch S2 is connected to the buck drive controller U1.
[0054] The drain of the third switch S3 is connected to the other end of the inductor L, the source of the third switch S3 is grounded, and the gate of the third switch S3 is connected to the boost drive controller U2.
[0055] The drain of the fourth switch S4 is connected to the other end of the inductor L, and the source of the fourth switch S4 is connected to the load R. L The positive electrode, load R L The negative terminal is grounded.
[0056] Filter capacitor C and load R L in parallel.
[0057] The buck drive controller U1 is connected to the gate of the first switch S1 and the gate of the second switch S2, respectively, and controls the conduction or cutoff of the first switch S1 and the second switch S2. The buck drive controller U1 can directly adopt the MCU master controller used in the prior art to control the buck circuit.
[0058] The boost drive controller U2 is connected to the gates of the third switch S3 and the fourth switch S4, respectively, and controls the on / off state of the third switch S3 and the fourth switch S4. The boost drive controller U2 can directly adopt the MCU master controller used in existing technology to control the boost circuit.
[0059] In some embodiments, the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4 are NMOS transistors.
[0060] In some embodiments, the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4 are enhancement-mode NMOS transistors.
[0061] In some embodiments, load R L It is an LED light.
[0062] In some embodiments, after the circuit topology of the present invention is powered on, it is necessary to collect the voltage of the power supply terminal Vin as the input voltage V. IS At the same time, it is necessary to collect the load R L The voltage is used as the output voltage V. OS The input voltage V IS With output side voltage V OS Compare them.
[0063] When the input voltage V IS Less than the output voltage V OS When, i.e., V IS <V OS At this time, the buck drive controller U1 controls the first switch S1 to always be in the on state and controls the second switch S2 to always be in the off state. The third switch S3 and the fourth switch S4 are controlled by the boost drive controller U2. At this time, the third switch S3, the fourth switch S4, the inductor L and the filter capacitor C in the circuit topology form a standard circuit as shown in the figure. Figure 3 The boost circuit architecture shown is illustrated. The third switch S3 is equivalent to... Figure 3 The typical boost circuit shown has a fourth switch S4 that is equivalent to... Figure 3 The rectifier diodes in the boost circuit are shown. The operating state of the circuit topology is controlled by the boost drive controller U2, which controls the conduction or cutoff of the third switch S3 and the fourth switch S4, for example, controlling the circuit topology to operate in boost mode.
[0064] When the input voltage V IS Greater than the output voltage V OS When, i.e., V IS >V OS At this time, the boost drive controller U2 controls the fourth switch S4 to always be in the on state and controls the third switch S3 to always be in the off state. The first switch S1 and the second switch S2 are controlled by the buck drive controller U1. At this time, the first switch S1, the second switch S2, the inductor L and the filter capacitor C in the circuit topology form a standard buck circuit architecture. Among them, the first switch S1 is equivalent to Figure 4 The switch in the buck circuit shown is represented by the second switch S2, which is equivalent to... Figure 4 The freewheeling diode in the buck circuit shown is used to control the operation of the circuit topology by controlling the on / off state of the first switch S1 and the second switch S2 through the buck drive controller U1. For example, the circuit topology is controlled to operate in buck mode.
[0065] In some embodiments, the circuit topology further includes a voltage acquisition and comparison circuit, which includes acquiring the voltage at the power supply terminal Vin and the voltage at the load R. L Voltage acquisition and comparison. This includes acquiring the voltage on the power supply side (Vin) and comparing the voltage on the load side (R). L The input voltage can be acquired using any existing circuit capable of voltage acquisition. For example, a sampling resistor can be used to acquire the load voltage. The voltage obtained from acquiring the voltage at the power supply terminal Vin is the input voltage V. IS For load RL The voltage obtained from the side voltage acquisition is the output side voltage V. OS .
[0066] Reference Figure 5 The voltage acquisition and comparison circuit includes a first input-side sampling resistor R. I1 Second input side sampling resistor R I2 First output side sampling resistor R F1 Second output side sampling resistor R F2 The first comparator com1 and the third comparator com3.
[0067] First input side sampling resistor R I1 With the second input side sampling resistor R I2 Series connection, specifically the first input side sampling resistor R I1 One end is connected to the power supply terminal Vin, and the second input side sampling resistor R I2 One end is connected to the first input side sampling resistor R I1 At the other end, the second input side sampling resistor R I2 The other end is grounded. The first input-side sampling resistor R... I1 With the second input side sampling resistor R I2 The voltage at the common terminal between them is the input voltage V. IS .
[0068] First output side sampling resistor R F1 With the second output side sampling resistor R F2 Series connection, specifically the first output side sampling resistor R F1 One end is connected to the load R L The positive terminal, the sampling resistor R on the first output side F1 The other end is connected to the second output side sampling resistor R. F2 One end, the second output side sampling resistor R F2 The other end is grounded. The first output side sampling resistor R... F1 With the second output side sampling resistor R F2 The voltage at the common terminal between them is the output voltage V. OS .
[0069] One input terminal of the first comparator COM1 is connected to the sampling resistor R on the first output side. F1 With the second output side sampling resistor R F2 The common terminal between them, and the other input terminal of the first comparator COM1 is connected to the first input-side sampling resistor R. I1 With the second input side sampling resistor R I2The common terminal between them, the output of the first comparator COM1 is connected to the boost drive controller U2, and the first comparator COM1 is used to compare the input voltage V. IS With output side voltage V OS The size between them is determined, and the comparison result is transmitted to the boost drive controller U2.
[0070] One input terminal of the third comparator COM3 is connected to the sampling resistor R on the first input side. I1 With the second input side sampling resistor R I2 The common terminal between them, and the other input terminal of the third comparator COM3 are connected to the sampling resistor R on the first output side. F1 With the second output side sampling resistor R F2 The common terminal between them, and the output of the third comparator COM3 are connected to the buck drive controller U1. The third comparator COM3 is used to compare the input voltage V. IS With output side voltage V OS The size between them is determined, and the comparison result is transmitted to the buck drive controller U1.
[0071] In some embodiments, refer to Figure 5 The circuit topology also includes a dynamic response circuit, which adopts RCOT control mode, specifically a ripple-type COT (constant on-time) controlled dynamic response circuit. RCOT control solves the problem of insufficient dynamic response in the prior art, so as to achieve the purpose of fast dynamic response.
[0072] The dynamic response circuit in this embodiment includes a trigger R. S The second comparator com2 and the timer CLK.
[0073] Trigger R S The buck drive controller U1 and boost drive controller U2 are connected respectively. The timer CLK is connected to the trigger RS. Therefore, in this embodiment, the trigger RS... S It is an RS trigger.
[0074] One input terminal of the second comparator COM2 is connected to the sampling resistor R on the first output side. F1 With the second output side sampling resistor R F2 The common terminal between the two, and the other input terminal of the second comparator COM2 is connected to the preset reference voltage V. REF The output of the second comparator COM2 is connected to the set terminal of the flip-flop RS. The second comparator COM2 is used to compare the output voltage V. OS With reference voltage V REF The size between them is compared and the result is transmitted to the trigger R. S Among them, the reference voltage V REFIt is a voltage value predetermined based on the load connection situation in the actual scenario.
[0075] The dynamic response circuit described in this embodiment realizes the response when the input voltage V... IS During rapid rise or fall, the output voltage V OS It can also output quickly and stably. The implementation process is as follows:
[0076] When the output voltage V OS Less than the reference voltage V REF When the second comparator com2 flips, it sets the trigger RS, driving the buck drive controller U1 and the boost drive controller U2 to partially turn on the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4, causing the inductor L current to rise until the timer CLK overflows. The trigger RS then resets, driving the buck drive controller U1 and the boost drive controller U2 to change the state of the first switch S1, the second switch S2, the third switch S3, and the fourth switch S4, causing the inductor L current to decrease. Through this entire control process, the output voltage can be rapidly regulated.
[0077] This invention also provides an automotive lamp having the circuit topology provided in the above embodiments of this invention, which enables RCOT modulation and adaptive buck-boost.
[0078] The present invention has been described in detail above with reference to the accompanying drawings and embodiments. Those skilled in the art can make various modifications to the present invention based on the above description. Therefore, certain details in the embodiments should not be construed as limiting the present invention, and the scope of protection of the present invention shall be defined by the appended claims.
Claims
1. A circuit topology capable of RCOT modulation and adaptive buck-boost, the circuit topology comprising a power supply terminal and a load, wherein the negative terminal of the load is grounded, characterized in that, The circuit topology also includes: The first switching transistor has its drain connected to the power supply terminal and its source connected to one end of an inductor. The second switch has its drain connected to the source of the first switch, and its source is grounded. The third switching transistor has its drain connected to the other end of the inductor and its source grounded. A fourth switching transistor, the drain of which is connected to the other end of the inductor, and the source of which is connected to the positive terminal of the load; A filter capacitor, wherein the filter capacitor is connected in parallel with the load; A buck drive controller, wherein the buck drive controller is connected to the gate of the first switch and the gate of the second switch respectively; A boost drive controller is connected to the gate of the third switch and the gate of the fourth switch, respectively.
2. The circuit topology capable of RCOT modulation and adaptive buck-boost as described in claim 1, characterized in that, The first switch, the second switch, the third switch, and the fourth switch are all NMOS transistors.
3. The circuit topology capable of RCOT modulation and adaptive buck-boost as described in claim 2, characterized in that, The first switch, the second switch, the third switch, and the fourth switch are enhancement-mode NMOS transistors.
4. The circuit topology capable of RCOT modulation and adaptive buck-boost as described in claim 1, characterized in that, The load is an LED light.
5. The circuit topology capable of RCOT modulation and adaptive buck-boost as described in any one of claims 1 to 4, characterized in that, After the circuit topology is powered on, the voltage at the power supply terminal is collected as the input voltage, and the voltage of the load is collected as the output voltage. When the input voltage is less than the output voltage, the buck driver controller controls the first switch to always be on and the second switch to always be off, forming a boost circuit architecture. The boost driver controller controls the third and fourth switches to be on or off to control the operating state of the circuit topology. When the input voltage is greater than the output voltage, the boost drive controller controls the fourth switch to always be on and the third switch to always be off. The circuit topology forms a buck circuit architecture. The buck drive controller controls the first and second switches to be on or off to control the operating state of the circuit topology.
6. The circuit topology capable of RCOT modulation and adaptive buck-boost as described in claim 5, characterized in that, The circuit topology further includes a voltage acquisition and comparison circuit, which includes: A first input-side sampling resistor, one end of which is connected to the power supply terminal; A second input-side sampling resistor, one end of which is connected to the other end of the first input-side sampling resistor, and the other end of which is grounded; A first output-side sampling resistor, one end of which is connected to the positive terminal of the load; The second output-side sampling resistor has one end connected to the other end of the first output-side sampling resistor, and the other end of the second output-side sampling resistor is grounded. A first comparator has one input terminal connected to the common terminal between the first output-side sampling resistor and the second output-side sampling resistor, and another input terminal connected to the common terminal between the first input-side sampling resistor and the second input-side sampling resistor. The output terminal of the first comparator is connected to the boost drive controller. The third comparator has one input terminal connected to the common terminal between the first input-side sampling resistor and the second input-side sampling resistor, and the other input terminal connected to the common terminal between the first output-side sampling resistor and the second output-side sampling resistor. The output terminal of the third comparator is connected to the buck drive controller.
7. The circuit topology capable of RCOT modulation and adaptive buck-boost as described in claim 6, characterized in that, The circuit topology also includes a dynamic response circuit, which includes: Triggers, which are respectively connected to the buck drive controller and the boost drive controller; The second comparator has one input terminal connected to the common terminal between the first output sampling resistor and the second output sampling resistor, another input terminal connected to a preset reference voltage, and an output terminal connected to the set terminal of the flip-flop. A timer, which is connected to the trigger.
8. The circuit topology capable of RCOT modulation and adaptive buck-boost as described in claim 7, characterized in that, When the voltage at the common terminal between the first output-side sampling resistor and the second output-side sampling resistor is less than the reference voltage, the second comparator flips, setting the trigger and driving the buck drive controller and the boost drive controller to partially turn on the first, second, third, and fourth switches, causing the inductor current to rise until the timer overflows. The trigger then resets, driving the buck drive controller and the boost drive controller to change the states of the first, second, third, and fourth switches, causing the inductor current to decrease.
9. A type of automotive lamp, characterized in that, The automotive lamp has a circuit topology that enables RCOT modulation and adaptive buck-boost as described in any one of claims 1 to 8.