Driving circuit and lighting device

Abstract

The application discloses a driving circuit and a lighting device. The driving circuit comprises a DC / DC circuit, a control module, a dimming circuit and an adaptive circuit. One end of the DC / DC circuit is connected to a first voltage source, the other end of the DC / DC circuit is electrically connected to the positive electrode of an LED lamp, the dimming circuit is electrically connected to the control module and the negative electrode of the LED lamp respectively, and is configured to control the brightness of the LED lamp according to a pulse width signal output by the control module. The adaptive circuit is electrically connected to the negative electrode of the LED lamp and the DC / DC circuit respectively. The control module is electrically connected to the DC / DC circuit and the adaptive circuit respectively and is configured to drive the DC / DC circuit to work and input a first voltage signal to the adaptive circuit. The adaptive circuit inputs a feedback signal to the DC / DC circuit according to the first voltage signal and a second voltage signal input by the negative electrode of the LED lamp, thereby reducing the output voltage of the DC / DC circuit and improving the dimming efficiency of the LED lamp.

Description

Technical Field

[0001] This application relates to the field of LED lighting control technology, and in particular to a driving circuit and lighting device. Background Technology

[0002] LED lights are lighting devices that use light-emitting diodes (LEDs) as their light source, directly converting electrical energy into visible light. LED lights offer numerous advantages, including high energy efficiency, long lifespan, environmental friendliness, mercury-free operation, fast response time, and robust construction. Compared to traditional incandescent and fluorescent lamps, LED lights exhibit significant advantages in energy consumption, lifespan, and environmental performance. However, when controlled by a driver circuit, LED lights suffer from relatively low dimming efficiency. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this application provides a driving circuit and lighting device that can improve the dimming efficiency of LED lights, reduce heat dissipation pressure, and enhance product reliability.

[0004] To address the aforementioned problems, in a first aspect, this application provides a driving circuit comprising: The DC / DC circuit includes a power input terminal, a power output terminal, a feedback terminal, and an enable terminal; the power input terminal is connected to a first voltage source, and the power output terminal is electrically connected to the positive terminal of an LED lamp. An adaptive circuit includes a setting signal input terminal, a sampling signal input terminal, and a feedback signal output terminal; the sampling signal input terminal is electrically connected to the negative terminal of the LED, and the feedback signal output terminal is electrically connected to the feedback terminal of the DC / DC circuit. The control module has its enable control terminal electrically connected to the enable terminal of the DC / DC circuit, its set signal output terminal electrically connected to the set signal input terminal of the adaptive circuit, and inputs a first voltage signal to the adaptive circuit and outputs a pulse width signal to the dimming circuit. A dimming circuit, wherein the pulse width signal input terminal of the dimming circuit is electrically connected to the pulse width signal output terminal of the control module, and the voltage adjustment terminal is electrically connected to the negative terminal of the LED lamp, and is configured to control the brightness of the LED lamp according to the pulse width signal; The adaptive circuit includes a first operational amplifier, one of which is the set signal input terminal and the other is the sampling signal input terminal. The first output terminal of the first operational amplifier is the feedback signal output terminal, so as to input a feedback signal to the feedback terminal of the DC / DC circuit according to the first voltage signal and the second voltage signal input to the negative terminal of the LED.

[0005] Furthermore, in the driving circuit provided in this application, the voltage detection input terminal of the control module is electrically connected to the anode of the target diode, the cathode of the target diode is connected to the cathode of the LED, and is configured to output the first voltage signal according to the second voltage signal.

[0006] Furthermore, in the driving circuit provided in this application, the first voltage signal is a pulse width modulation signal, and the control module sets the target voltage value of the negative electrode of the LED by adjusting the duty cycle of the first voltage signal.

[0007] Furthermore, in the driving circuit provided in this application, the adaptive circuit also includes a first switching transistor; The first terminal of the first switching transistor is electrically connected to the first output terminal of the first operational amplifier and the feedback terminal of the DC / DC circuit, the second terminal of the first switching transistor is grounded, and the control terminal of the first switching transistor is electrically connected to the control module.

[0008] Furthermore, in the driving circuit provided in this application, the DC / DC circuit includes a buck controller, a second switching transistor, a third switching transistor, and an inductor; The feedback terminal of the step-down controller is electrically connected to the output terminal of the adaptive circuit, the first driving terminal is electrically connected to the control terminal of the second switching transistor, the second driving terminal is electrically connected to the control terminal of the third switching transistor, the switching node is electrically connected to one end of the inductor, the first end of the second switching transistor is connected to the first voltage source, the second end of the second switching transistor is electrically connected to the first end of the third switching transistor and one end of the inductor, the second end of the third switching transistor is grounded, and the other end of the inductor is electrically connected to the positive terminal of the LED.

[0009] Furthermore, in the driving circuit provided in this application, the DC / DC circuit also includes a fourth switching transistor; The first terminal of the fourth switch is connected to the first voltage source, the second terminal of the fourth switch is electrically connected to the first terminal of the third switch and one end of the inductor, and the control terminal of the fourth switch is electrically connected to the step-down controller.

[0010] Furthermore, in the driving circuit provided in this application, the dimming circuit includes a second operational amplifier, a fifth switching transistor, and a current sensing resistor; The second operational amplifier has a third input terminal, a fourth input terminal, and a second output terminal. The third input terminal is electrically connected to the pulse width signal output terminal of the control module. The fourth input terminal is electrically connected to one end of the current sensing resistor and the first end of the fifth switching transistor. The second output terminal is electrically connected to the control terminal of the fifth switching transistor. The second end of the fifth switching transistor is electrically connected to the negative terminal of the LED.

[0011] Furthermore, in the driving circuit provided in this application, the dimming circuit also includes a first resistor and a second resistor; One end of the first resistor is electrically connected to the fourth input terminal and one end of the second resistor, the other end of the first resistor is connected to the second voltage source, and the other end of the second resistor is electrically connected to one end of the current sensing resistor and the first terminal of the fifth switching transistor.

[0012] Furthermore, in the driving circuit provided in this application, the driving circuit also includes a conversion circuit; One end of the conversion circuit is electrically connected to the pulse width signal output terminal of the control module, and the other end of the conversion circuit is electrically connected to the third input terminal of the dimming circuit. The conversion circuit is configured to convert the pulse width signal output by the control module into an analog signal and input the analog signal into the dimming circuit.

[0013] Secondly, this application also provides a lighting device, which includes an LED lamp and the driving circuit provided in the first aspect.

[0014] The driving circuit provided in this application, while including a DC / DC circuit, a control module, and a dimming circuit, also incorporates an adaptive circuit. A first voltage signal is input to the adaptive circuit, which then provides a feedback signal to the DC / DC circuit based on the first voltage signal and a second voltage signal input to the negative terminal of the LED. This reduces the output voltage of the DC / DC circuit, improves the dimming efficiency of the LED, avoids the problem of severe overheating of electronic components during dimming, alleviates heat dissipation pressure, solves circuit response issues, saves software resources, reduces software complexity, and resolves the technical problems of slow and unstable loop response caused by software adaptation. This meets the needs of different application scenarios and enhances product reliability. Attached Figure Description

[0015] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 A first schematic block diagram of a lighting device provided in an embodiment of this application; Figure 2 This is a second schematic block diagram of a lighting device provided in an embodiment of this application; Figure 3 A circuit diagram of the adaptive circuit provided in the embodiments of this application; Figure 4 Circuit diagram of the DC / DC circuit provided in the embodiments of this application; Figure 5 A circuit diagram of the dimming circuit provided in the embodiments of this application; Figure 6 A circuit diagram of the conversion circuit provided in an embodiment of this application.

[0017] Figure label: 10. Lighting device; 100. Drive circuit; 110. DC / DC circuit; 120. Adaptive circuit; 130. Control module; 140. Dimming circuit; 141. Current sensing resistor; 142. First resistor; 143. Second resistor; 150. Conversion circuit; 200. LED lamp. Detailed Implementation

[0018] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0020] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the application. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0021] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0022] Furthermore, in this application, unless otherwise explicitly specified or limited in the embodiments, the terms "installation," "connection," "joining," and "fixing" appearing in the embodiments should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral part; it can also be a mechanical connection, an electrical connection, etc. Of course, it can also be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication between two components, or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific implementation.

[0023] In related technologies, when the current flowing through an LED lamp is different, the voltage across the LED lamp is also different. When the LED lamp is controlled by a driver circuit, the driver circuit does not have an adaptive circuit. It simply outputs a constant voltage through the DC / DC circuit in the driver circuit, resulting in low dimming efficiency of the LED lamp. At the same time, during the dimming process, the switching transistor in the dimming circuit heats up severely. To avoid excessive heat generation of the switching transistor, a parallel switching transistor needs to be added to the switching transistor to distribute the heat of the power switching transistor. However, adding a switching transistor will increase the cost of the product.

[0024] To address the technical issues of low dimming efficiency and severe overheating of the switching transistor, a software adaptive approach is typically employed. Specifically, the control module detects the voltage at the negative terminal of the LED and injects a pulse width signal into the feedback terminal of the DC / DC circuit to reduce the output voltage of the DC / DC circuit, thereby improving dimming efficiency. However, the delay between the control module detecting the actual output pulse width signal is too large, resulting in a slow loop response. If software issues arise, it can lead to loop instability, especially under dynamic load conditions, failing to meet product requirements.

[0025] To address this, this application provides a driving circuit that, in addition to a DC / DC circuit, a control module, and a dimming circuit, incorporates an adaptive circuit. A first voltage signal is input to the adaptive circuit, which then provides a feedback signal to the DC / DC circuit based on the first voltage signal and a second voltage signal input to the negative terminal of the LED. This reduces the output voltage of the DC / DC circuit, improves the dimming efficiency of the LED, avoids the problem of severe overheating of electronic components during dimming, alleviates heat dissipation pressure, solves circuit response issues, saves software resources, reduces software complexity, and resolves the technical problems of slow and unstable loop response caused by software adaptation. This meets the needs of different application scenarios and enhances product reliability.

[0026] like Figure 1 As shown, this application provides a driving circuit 100, which includes: DC / DC circuit 110 includes a power input terminal, a power output terminal, a feedback terminal, and an enable terminal; the power input terminal is connected to a first voltage source, and the power output terminal is electrically connected to the positive terminal of LED lamp 200. An adaptive circuit 120 includes a setting signal input terminal, a sampling signal input terminal, and a feedback signal output terminal; the sampling signal input terminal is electrically connected to the negative terminal of the LED lamp 200, and the feedback signal output terminal is electrically connected to the feedback terminal of the DC / DC circuit 110. The control module 130 has its enable control terminal electrically connected to the enable terminal of the DC / DC circuit 110, its set signal output terminal electrically connected to the set signal input terminal of the adaptive circuit 120, and inputs a first voltage signal to the adaptive circuit 120 and outputs a pulse width signal to the dimming circuit 140. A dimming circuit 140 is provided, wherein the pulse width signal input terminal of the dimming circuit 140 is electrically connected to the pulse width signal output terminal of the control module 130, and the voltage adjustment terminal is electrically connected to the negative terminal of the LED lamp 200, and is configured to control the brightness of the LED lamp 200 according to the pulse width signal. The adaptive circuit 120 includes a first operational amplifier U4. One of the non-inverting input terminal and the inverting input terminal of the first operational amplifier U4 is the setting signal input terminal, and the other is the sampling signal input terminal. The first output terminal of the first operational amplifier U4 is the feedback signal output terminal, so as to input a feedback signal to the feedback terminal of the DC / DC circuit 110 according to the first voltage signal and the second voltage signal input to the negative terminal of the LED lamp 200.

[0027] Specifically, the control module 130 can be an MCU (Microcontroller Unit). The microcontroller unit (MCU) chip and the control module 130 are electrically connected to the DC / DC circuit 110 and the adaptive circuit 120, respectively. The control module 130 can output an enable signal (EN) to the DC / DC circuit 110 to drive the DC / DC circuit 110 to work. At the same time, the control module 130 outputs a first voltage signal (PWM_Set_LED-) to the adaptive circuit 120. The adaptive circuit 120 is located between the negative terminal of the LED lamp 200 and the feedback pin of the DC / DC circuit 110, and receives the second voltage signal output from the negative terminal of the LED lamp 200. Then, the adaptive circuit 120 can output a corresponding feedback signal (FB) to the feedback terminal of the DC / DC circuit 110 according to the first voltage signal and the second voltage signal. Meanwhile, the control module 130 controls the duty cycle of the first voltage signal, so that the voltage at the negative terminal of the LED lamp 200 is consistent with the target voltage value set at the positive terminal. This avoids the problem of severe overheating of the switching transistor in the dimming circuit 140 during the dimming process, reduces the heat dissipation pressure, and enhances the reliability of the product.

[0028] In this application, the DC / DC circuit 110 can be understood as a BUCK circuit, and the dimming circuit 140 can perform constant current control on the LED lamp 200. The control module 130 is electrically connected to the dimming circuit 140 and can output a pulse width signal to the dimming circuit 140 to control the duty cycle of the pulse width signal, thereby adjusting the brightness of the LED lamp 200. By setting an adaptive circuit 120 in the driver circuit 100, this application can ensure that the voltage (1.6V) at the negative terminal of the LED lamp 200 remains constant. Even if there are differences in the consistency of the light source, it can ensure that the power consumption of the switching transistor in the dimming circuit 140 is reduced, thus reducing heat generation.

[0029] The driving circuit 100 provided in this application, in addition to setting up a DC / DC circuit 110, a control module 130, and a dimming circuit 140, also introduces an adaptive circuit 120. One end of the DC / DC circuit 110 is connected to a first voltage source, and the other end of the DC / DC circuit is electrically connected to the positive terminal of the LED lamp 200. The dimming circuit 140 is electrically connected to both the control module 130 and the negative terminal of the LED lamp 200, and is configured to control the brightness of the LED lamp 200 according to the pulse width signal output by the control module 130. The adaptive circuit 120 is electrically connected to both the negative terminal of the LED lamp 200 and the DC / DC circuit 110. The control module 130 is electrically connected to both the DC / DC circuit 110 and the adaptive circuit 120 and is configured to drive... The DC / DC circuit 110 operates and inputs a first voltage signal to the adaptive circuit 120. The adaptive circuit 120 can then input a feedback signal to the DC / DC circuit 110 based on the first voltage signal and the second voltage signal input to the negative terminal of the LED 200. This reduces the output voltage of the DC / DC circuit 110, improves the dimming efficiency of the LED 200, avoids the problem of severe overheating of electronic components in the dimming circuit 140 during dimming, alleviates heat dissipation pressure, solves the circuit response problem, saves software resources, reduces software complexity, and resolves the technical problems of slow and unstable loop response caused by software adaptation. This meets the needs of different application scenarios and enhances the reliability of the product.

[0030] For example, the power input terminal can be pin V_SYS (54V) of DC / DC circuit 110; the power output terminal can be pin LED+ of DC / DC circuit 110; the sampling signal input terminal can be pin V_Sense_LED- of adaptive circuit 120; the feedback signal output terminal can be pin FB of adaptive circuit 120; the enable control terminal can be pin EN of control module 130; the setting signal output terminal can be pin PWM_Set_LED- of control module 130; the setting signal input terminal can be pin PWM_Set_LED- of adaptive circuit 120; the pulse width signal input terminal can be pin DAC of dimming circuit 140; the pulse width signal output terminal can be pin PWM of control module 130; and the voltage adjustment terminal can be pin LED- of dimming circuit 140.

[0031] In some embodiments, such as Figure 3 As shown, the adaptive circuit 120 includes a first operational amplifier U4; wherein the first operational amplifier U4 has a first input terminal, a second input terminal and a first output terminal; the first input terminal is electrically connected to the control module 130 and is configured to input a first voltage signal; the second input terminal is electrically connected to the negative terminal of the LED lamp 200 and is configured to input a second voltage signal; the first output terminal is electrically connected to the DC / DC circuit 110 and is configured to input a feedback signal to the DC / DC circuit 110.

[0032] In this application, by designing an operational amplifier in the adaptive circuit 120 to adjust the loop, the voltage (1.6V) at the negative terminal of the LED lamp 200 can be kept constant. Even if there are differences in the consistency of the light source, the power consumption of the switching transistor in the dimming circuit 140 can be reduced, thus reducing heat generation. The first operational amplifier U4 can be an SGM8557-1.

[0033] Specifically, the first operational amplifier U4 provided in this application has pins +IN, -IN, +Vs, -Vs, and OUT. Pins +IN and -IN can be used as the first input terminal and the second input terminal of the first operational amplifier U4, respectively. Pin OUT can be used as the first output terminal. One end of pin +IN is electrically connected to one end of resistor R30, one end of resistor R31, one end of capacitor C30, and the positive terminal of target diode D3. The other end of resistor R30 is connected to a +5V voltage source. The other end of resistor R31 and the other end of capacitor C30 are grounded to GND. The negative terminal of target diode D3 is electrically connected to the negative terminal of LED 200. Pin -IN is electrically connected to one end of resistor R32, one end of resistor R33, one end of capacitor C40, and one end of resistor R45. The other end of resistor R32 is grounded to GND. The other end of resistor R33 is electrically connected to one end of R35 and one end of capacitor C40. One end of resistor R34 and the other end of resistor R35 are electrically connected to one end of resistor R34, one end of resistor R41, and one end of capacitor C33, respectively. The other end of resistor R34 is electrically connected to control module 130. The other end of resistor R41 is connected to a +3.3V voltage source. The other ends of capacitor C33 and capacitor C34 are grounded to GND. The other end of capacitor C40 is electrically connected to pin OUT through resistor R42. The other end of resistor R45 is electrically connected to pin OUT. Pin OUT is electrically connected to one end of resistor R36. The other end of resistor R36 is electrically connected to one end of capacitor C38 and one end of resistor R37, respectively. The other end of resistor R37 is electrically connected to one end of resistor R38 and one end of capacitor C39, respectively. The other ends of capacitor C39 and capacitor C38 are both grounded to GND. The other end of resistor R38 is electrically connected to the positive terminal of diode D4. The negative terminal of diode D4 is electrically connected to the feedback terminal of DC / DC circuit 110. Meanwhile, pin +Vs is connected to a +5V voltage source and grounded to GND through capacitor C36 and capacitor C42, while pin -Vs is grounded to GND.

[0034] Furthermore, in some embodiments, such as Figure 1 As shown, the voltage detection input terminal of the control module 130 is electrically connected to the anode of the target diode D3, and the cathode of the target diode D3 is electrically connected to the cathode of the LED lamp 200, and is configured to output a first voltage signal according to the second voltage signal.

[0035] In this application, one pin of the control module 130 can be electrically connected to the negative terminal of the LED 200, thereby enabling the detection of the voltage at the negative terminal of the LED 200. This allows for verification of whether the actual voltage at the negative terminal of the LED 200 matches the set voltage. A first voltage signal (PWM_Set_LED-) with a duty cycle is then output to the adaptive circuit 120, ensuring that the voltage at the negative terminal of the LED 200 is the set voltage. This guarantees that the voltage (1.6V) at the negative terminal of the LED 200 remains constant. Even if there are differences in the consistency of the light source, the power consumption of the switching transistor in the dimming circuit 140 is reduced, thus minimizing heat generation. For example, the voltage detection input can be pin V_Sense_LED- in the control module 130.

[0036] The anode of the target diode D3 serves as the forward input terminal, allowing the control module 130 to indirectly detect the voltage signal at the negative terminal of the LED 200 via the target diode D3. The target diode D3 can be a Schottky diode, a standard rectifier diode, or a Zener diode; the specific type can be determined based on the required voltage detection accuracy, response speed, and protection requirements for the negative terminal of the LED 200. Simultaneously, the cathode of the target diode D3 is connected to the negative terminal of the LED 200, enabling it to directly sense or transmit the voltage at the negative terminal of the LED 200, i.e., the second voltage signal. This ensures that the target diode D3 can monitor the actual operating voltage of the negative terminal of the LED 200 in real time. During normal operation of the LED 200, the negative terminal voltage fluctuates with changes in the current flowing through the LED 200 and its brightness. The target diode D3 can function as a unidirectional conductor, provide reverse isolation, or clamp voltage, for example, preventing accidental reverse current from flowing into the negative terminal of the LED 200, or providing a stable reference voltage under specific operating conditions.

[0037] In some embodiments, the first voltage signal is a pulse width modulation signal, and the control module sets the target voltage value of the negative electrode of the LED by adjusting the duty cycle of the first voltage signal.

[0038] Specifically, the first voltage signal is configured as a pulse-width modulated (PWM) signal, which is essentially a digital signal that represents information by periodically switching between preset high and low levels. A key characteristic of this signal is its variable duty cycle (the ratio of the high-level duration to the total period within a cycle). By changing the duty cycle, the average voltage or average power of the signal over a period of time can be effectively controlled, thereby achieving precise digital control of the analog quantity. For example, the control module 130 can utilize its internal timer and comparator modules to generate a PWM signal with a specific frequency and duty cycle. To avoid negatively impacting system performance, the frequency of this PWM signal is typically designed to be sufficiently high to prevent perceptible flicker or audible noise.

[0039] Based on this, the control module 130 sets the target voltage value of the negative electrode of the LED lamp 200 by actively adjusting the duty cycle of the first voltage signal. Specifically, the control module 130, typically a microcontroller or digital signal processor, can calculate the required target voltage value according to a preset control algorithm or external input (such as user instructions, sensor data, etc.) and convert it into a corresponding pulse width modulation signal duty cycle. The control module 130 generates a first voltage signal with this duty cycle and sends it to the adaptive circuit 120. After receiving the pulse width modulation signal, the adaptive circuit 120 can use the average value as a reference voltage, or convert it into an analog voltage proportional to the duty cycle through internal circuitry (such as a low-pass filter), as the setting signal received at the setting signal input terminal, thereby accurately setting the target voltage value of the negative electrode of the LED lamp 200.

[0040] Through the above technical solution, the first voltage signal is designed as a pulse width modulation (PWM) signal, and the control module 130 sets the target voltage value of the negative electrode of the LED lamp 200 by adjusting its duty cycle, effectively solving the limitations of analog voltage signals in terms of accuracy and dynamics. The introduction of the PWM signal enables the control module 130 to perform high-resolution, wide-range fine adjustment of the target voltage value digitally, improving the flexibility and accuracy of voltage setting. The adaptive circuit 120 can generate a feedback signal more accurately based on the set PWM signal, thereby enabling the DC / DC circuit 110 to maintain the voltage of the negative electrode of the LED lamp 200 at the desired target value more stably and accurately.

[0041] Furthermore, in some embodiments, such as Figure 3 As shown, the adaptive circuit 120 also includes a first switching transistor Q5; wherein, the first terminal of the first switching transistor Q5 is electrically connected to the first output terminal and the feedback terminal of the first operational amplifier U4, the second terminal of the first switching transistor Q5 is grounded to GND, and the control terminal of the first switching transistor Q5 is electrically connected to the control module 130.

[0042] In this application, the adaptive circuit 120 may also include a first switching transistor Q5. The first terminal of the first switching transistor Q5 is electrically connected to the first output terminal of the first operational amplifier U4 and the feedback terminal of the DC / DC circuit 110, respectively. The second terminal of the first switching transistor Q5 can be grounded (GND). Simultaneously, the control terminal of the first switching transistor Q5 can be controlled by the control module 130, thereby allowing the signal at the feedback terminal of the DC / DC circuit 110 to be cut off at any time. The first switching transistor Q5 can be a MOSFET, with its first and second terminals being the source and drain, respectively, and its control terminal being the gate.

[0043] Specifically, the first terminal of the first switch Q5 is electrically connected to the other end of the resistor R38 and the positive terminal of the diode D4, the second terminal of the first switch Q5 is grounded to GND, the control terminal of the first switch Q5 is grounded to GND through the resistor R46 and also through the capacitor C44, and the control terminal of the first switch Q5 is electrically connected to the control module 130 through the resistor R44.

[0044] In some embodiments, such as Figure 4 As shown, the DC / DC circuit 110 includes a buck controller U2, a second switch Q1, a third switch Q3, and an inductor L1. The feedback terminal of the buck controller U2 is electrically connected to the output terminal of the adaptive circuit 120, the first drive terminal is electrically connected to the control terminal of the second switch Q1, the second drive terminal is electrically connected to the control terminal of the third switch Q3, and the switching node is electrically connected to one end of the inductor L1. The first end of the second switch Q1 is connected to a first voltage source, and the second end of the second switch Q1 is electrically connected to the first end of the third switch Q3 and one end of the inductor L1. The second end of the third switch Q3 is grounded to GND, and the other end of the inductor L1 is electrically connected to the positive terminal of the LED lamp 200.

[0045] In this application, the DC / DC circuit 110 can perform DC-DC conversion on the first voltage source to convert its voltage into the voltage required by the LED lamp 200. The DC / DC circuit 110 includes a buck controller U2, a second switch Q1, a third switch Q3, and an inductor L1. The buck controller U2 can be an SCT82A32, which is a 100V voltage-mode controlled synchronous buck controller U2 with linear feedforward function, enabling direct buck conversion from a 48V input to a low voltage rail, reducing system complexity and solution cost. Both the second switch Q1 and the third switch Q3 can be MOSFETs; the second switch Q1 can be a power switch, and the third switch Q3 can be a freewheeling switch.

[0046] Specifically, the buck controller U2 has pins EN, VIN, RT, SS, COMP, FB, AGND, SYNCIN, PAD, ILIM, BST, UGATE, switch node (pin SW), NC, EP, VCC, LGATE, and PGND. Pin FB can be used as the feedback terminal of DC / DC circuit 110, and pin EN can be used as the enable terminal of DC / DC circuit 110. Pin EN is electrically connected to one end of resistor R3, one end of resistor R7, and one end of capacitor C12. The other end of resistor R3 is electrically connected to control module 130, and the other ends of resistor R7 and capacitor C12 are grounded to GND. Pin VIN serves as the power supply terminal for the buck controller U2, drawing power from the 54V first voltage source (V_SYS). Pin VIN is electrically connected to one end of resistor R2 and one end of capacitor C11. The other end of capacitor C11 is grounded to GND. The other end of resistor R2 is electrically connected to the first end of the second switch Q1, one end of capacitor C4, one end of capacitor C5, one end of capacitor C6, one end of capacitor C7, one end of capacitor C8, one end of capacitor C9, and one end of capacitor C10, and connected to the 54V first voltage source (V_SYS). The other ends of capacitors C4, C5, C6, C7, C8, C9, and C10 are all grounded to GND.

[0047] Meanwhile, pin RT is grounded to GND through resistor R10, pin SS is grounded to GND through capacitor C15, pin COMP is electrically connected to one end of capacitor C14 and one end of capacitor C22, pin FB is electrically connected to the other end of capacitor C22, one end of resistor R13, one end of resistor R14, one end of resistor R18, one end of capacitor C23, and adaptive circuit 120, the other end of resistor R13 is electrically connected to the other end of capacitor C14, the other end of resistor R18 is grounded to GND, and the other end of resistor R14 is electrically connected to the positive terminal of LED 200 through resistor R8. The other end of C23 is electrically connected to the positive terminal of LED 200 through resistor R9; pin AGND is grounded to GND, pin SYNCIN is connected to a 7.5V voltage source through resistor R21, pin PAD is grounded to GND, pin ILIM is grounded to GND through capacitor C29 and electrically connected to one end of resistor R25, the other end of resistor R25 is electrically connected to pin SW; pin BST is electrically connected to pin SW through capacitor C16; the first drive terminal (pin UGATE) is electrically connected to one end of resistor R5 and one end of resistor R11 respectively, and the other end of resistor R5 is electrically connected to resistor R6. One end of resistor R12 is connected to the positive terminal of Zener diode D1. The other end of resistor R11 is electrically connected to the negative terminal of Zener diode D1. The other end of resistor R6 is electrically connected to the control terminal of the second switch Q1. The other end of resistor R12 is electrically connected to the control terminal of the fourth switch Q2. The second end of the second switch Q1 is electrically connected to pin SW and one end of inductor L1. Pin SW is electrically connected to the first end of the third switch Q3, the other end of resistor R25, and one end of capacitor C28. The other end of inductor L1 is electrically connected to one end of capacitor C17, one end of capacitor C18, and one end of capacitor C19. One end of capacitor C20, one end of capacitor C21, one end of capacitor C4, one end of capacitor C5, one end of capacitor C27, one end of resistor R15, one end of resistor R16, one end of resistor R17, and the positive terminal of LED 200. The other ends of capacitor C17, capacitor C18, capacitor C19, capacitor C20, capacitor C21, capacitor C4, capacitor C5, capacitor C27, resistor R15, resistor R16, and resistor R17 are all grounded to GND.

[0048] Additionally, pin NC is electrically connected to pin EP, and pin NC is grounded to GND. Pin VCC is grounded to GND through capacitor C26. The second drive terminal (pin LGATE) is electrically connected to one end of resistor R19 and one end of resistor R24. The other end of resistor R19 is electrically connected to one end of resistor R20 and the positive terminal of Zener diode D2. The negative terminal of Zener diode is electrically connected to the other end of resistor R24. The other end of resistor R20 is electrically connected to the control terminal of the third switch Q3 and grounded to GND through resistor R22. The second terminal of the third switch Q3 is grounded to GND. The other end of capacitor C28 is grounded to GND through resistor R23. Pin PGND is grounded to GND.

[0049] Furthermore, in some embodiments, such as Figure 4 As shown, the DC / DC circuit 110 also includes a fourth switch Q2; wherein, the first terminal of the fourth switch Q2 is connected to the first voltage source, the second terminal of the fourth switch Q2 is electrically connected to the first terminal of the third switch Q3 and one end of the inductor L1 respectively, and the control terminal of the fourth switch Q2 is electrically connected to the buck controller U2.

[0050] In this application, a fourth switch, Q2, can be connected in parallel at the second switch Q1. The first terminal of the fourth switch Q2 is electrically connected to the first voltage source (V_SYS) of 54V and one terminal of the resistor R4. The other terminal of the resistor R4 is electrically connected to the second terminal of the fourth switch Q2, the second terminal of the second switch Q1, the first terminal of the third switch Q3, and one terminal of the inductor L1 through the capacitor C13.

[0051] In some embodiments, such as Figure 5 As shown, the dimming circuit 140 includes a second operational amplifier U3, a fifth switching transistor Q4, and a current sensing resistor 141. The second operational amplifier U3 has a third input terminal, a fourth input terminal, and a second output terminal. The third input terminal is electrically connected to the pulse width signal output terminal of the control module 130. The fourth input terminal is electrically connected to one end of the current sensing resistor 141 and the first end of the fifth switching transistor Q4. The second output terminal is electrically connected to the control terminal of the fifth switching transistor Q4. The second end of the fifth switching transistor Q4 is electrically connected to the negative terminal of the LED lamp 200.

[0052] In this application, the second operational amplifier U3 can also be an SGM8557-1. The second operational amplifier has pins +IN, -IN, +Vs, -Vs, and OUT. Pins +IN and -IN can be used as the third and fourth input terminals of the second operational amplifier U3, respectively, and pin OUT can be used as the second output terminal. The current sensing resistor 141 can include two parallel resistors R49 and R50. Meanwhile, the fifth switching transistor Q4 can be a MOSFET, and it can operate in the constant current region to adjust the LED 200.

[0053] Specifically, pin +IN is electrically connected to one end of capacitor C32 and one end of resistor R28. The other end of resistor R28 is electrically connected to one end of resistor R29 and one end of resistor R27. The other end of resistor R27 is electrically connected to one end of capacitor C31 and one end of resistor R26. The other end of resistor R26 is electrically connected to control module 130. The other ends of capacitor C31, resistor R29, and capacitor C32 are all grounded (GND). Pin -IN is electrically connected to one end of capacitor C37, one end of capacitor C43, one end of capacitor C45, and one end of resistor R47. The other end of resistor R47 is electrically connected to one end of resistor R49 and one end of resistor R50. The other ends of resistors R49 and R50 are grounded to GND. The +Vs pin is connected to a +5V voltage source and grounded to GND through parallel capacitors C35 and C41. The -Vs pin is grounded to GND. The OUT pin is electrically connected to one end of resistor R39, one end of resistor R40, and the other end of capacitor C43. The other end of resistor R40 is electrically connected to the other end of capacitor C37. The other end of resistor R39 is electrically connected to the control terminal of the fifth switch Q4 and grounded to GND through resistor R43. The second terminal of the fifth switch Q4 is electrically connected to the negative terminal of LED 200. The first terminal of the fifth switch Q4 is electrically connected to one end of resistor R49 and one end of resistor R50.

[0054] In some embodiments, such as Figure 5 As shown, the dimming circuit 140 also includes a first resistor 142 and a second resistor 143; wherein, one end of the first resistor 142 is electrically connected to the fourth input terminal and one end of the second resistor 143 respectively, the other end of the first resistor 142 is connected to the second voltage source, and the other end of the second resistor 143 is electrically connected to one end of the current sensing resistor 141 and the first terminal of the fifth switching transistor Q4 respectively.

[0055] In this application, the first resistor 142 can be a resistor R48, and the second resistor 143 can be a resistor R47. In this application, one end of the first resistor 142 is electrically connected to the fourth input terminal and one end of the second resistor 143, and the other end of the first resistor 142 is connected to the second voltage source. The other end of the second resistor 143 is electrically connected to one end of the current sensing resistor 141 and the first end of the fifth switching transistor Q4, thereby forming a DC bias voltage at the second input terminal of the second operational amplifier U3.

[0056] In some embodiments, such as Figure 2 and Figure 6As shown, the driving circuit 100 also includes a conversion circuit 150; wherein, one end of the conversion circuit 150 is electrically connected to the pulse width signal output terminal of the control module 130, and the other end of the conversion circuit 150 is electrically connected to the third input terminal of the dimming circuit 140. The conversion circuit 150 is configured to convert the pulse width signal output by the control module 130 into an analog signal and input the analog signal into the dimming circuit 140.

[0057] In this application, the conversion circuit 150 can convert the pulse width signal (PWM) output by the control module 130 into an analog signal and input it into the dimming circuit 140 to control the current flowing through the LED lamp 200, thereby controlling the brightness of the LED lamp 200. The conversion circuit 150 can be implemented using a PWM signal to analog signal converter, such as the GP8101S-TC50-EW.

[0058] Specifically, the conversion circuit 150 has pins PWM, VCC, V5V, SEL, VOUT, GND, and PAD. Pin PWM is electrically connected to the control module 130. Pin VCC is connected to a +12V voltage source and grounded to GND through capacitor C2. Pin V5V is grounded to GND through capacitor C1. Pin SEL is grounded to GND through resistor R1. Pin VOUT is electrically connected to the dimming circuit 140 and grounded to GND through capacitor C3. Pins GND and PAD are both grounded to GND.

[0059] In some embodiments, this application also provides a lighting device 10, which includes an LED lamp 200 and a driving circuit 100 provided in this application.

[0060] Specifically, the lighting device provided in this application can be equipped with multiple LED lights 200, which can be connected in series and parallel. After the lighting device 10 is powered on, the control module 130 controls the enable terminal of the DC / DC circuit 110 to drive the DC / DC circuit 110 to operate. Then, the control module 130 can output a first voltage signal (PWM_Set_LED-) with a preset duty cycle (e.g., 50%) to ensure that the voltage at the negative terminal of the LED light 200 is a preset voltage (e.g., 1.6V). Then, the control module 130... The pulse width signal (PWM), i.e. the dimming signal, is then output to light up the LED 200. At the same time, the adaptive circuit 120 is also in operation. Regardless of how the current of the LED 200 changes, this application can reduce or increase the output voltage of the DC / DC circuit 110 through the adaptive circuit 120, so that the voltage at the negative terminal of the LED 200 is maintained at the preset voltage. Even if there are differences in the consistency of the light source, the power loss of the switching transistor (the fifth switching transistor Q4) in the dimming circuit 140 can be reduced, the heat generation can be reduced, and the response and stability of the circuit can be guaranteed.

[0061] The driving circuit 100 and lighting device 10 provided in this application adopt an operational amplifier design for the adaptive circuit 120 and adjust the loop through hardware circuitry. At the same time, the detection and pulse width signal input functions of the control module 130 are retained. This solves the problem of slow loop response and improves the flexibility of the hardware adaptive circuit 120. This solves the problems of low dimming efficiency, high cost, software adaptation, slow and unstable loop response of the LED lamp 200.

[0062] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this application, and these modifications or substitutions should all be covered within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A driving circuit (100), characterized in that, include: DC / DC circuit (110), the DC / DC circuit (110) includes a power input terminal, a power output terminal, a feedback terminal and an enable terminal; the power input terminal is connected to a first voltage source and the power output terminal is electrically connected to the positive terminal of an LED lamp (200); An adaptive circuit (120) includes a setting signal input terminal, a sampling signal input terminal, and a feedback signal output terminal; the sampling signal input terminal is electrically connected to the negative terminal of the LED lamp (200), and the feedback signal output terminal is electrically connected to the feedback terminal of the DC / DC circuit (110); The control module (130) has its enable control terminal electrically connected to the enable terminal of the DC / DC circuit (110), its set signal output terminal electrically connected to the set signal input terminal of the adaptive circuit (120), and inputs a first voltage signal to the adaptive circuit (120) and outputs a pulse width signal to the dimming circuit (140). A dimming circuit (140) is configured to control the brightness of the LED lamp (200) according to the pulse width signal input terminal of the control module (130) and the voltage adjustment terminal of the control module (130). The adaptive circuit (120) includes a first operational amplifier (U4), one of the non-inverting input terminal and the inverting input terminal of the first operational amplifier (U4) is the setting signal input terminal, and the other is the sampling signal input terminal. The first output terminal of the first operational amplifier (U4) is the feedback signal output terminal, so as to input a feedback signal to the feedback terminal of the DC / DC circuit (110) according to the first voltage signal and the second voltage signal input to the negative terminal of the LED lamp (200).

2. The driving circuit (100) according to claim 1, characterized in that, The voltage detection input terminal of the control module (130) is electrically connected to the anode of the target diode (D3), the cathode of the target diode (D3) is connected to the cathode of the LED lamp (200), and is configured to output the first voltage signal according to the second voltage signal.

3. The driving circuit (100) according to claim 1, characterized in that, The first voltage signal is a pulse width modulation signal, and the control module sets the target voltage value of the negative electrode of the LED by adjusting the duty cycle of the first voltage signal.

4. The driving circuit (100) according to claim 3, characterized in that, The adaptive circuit (120) also includes a first switching transistor (Q5); The first terminal of the first switch (Q5) is electrically connected to the first output terminal of the first operational amplifier (U4) and the feedback terminal of the DC / DC circuit (110), the second terminal of the first switch (Q5) is grounded, and the control terminal of the first switch (Q5) is electrically connected to the control module (130).

5. The driving circuit (100) according to claim 1, characterized in that, The DC / DC circuit (110) includes a buck controller (U2), a second switch (Q1), a third switch (Q3), and an inductor (L1). The feedback terminal of the step-down controller (U2) is electrically connected to the output terminal of the adaptive circuit (120), the first driving terminal is electrically connected to the control terminal of the second switch (Q1), the second driving terminal is electrically connected to the control terminal of the third switch (Q3), and the switching node is electrically connected to one end of the inductor (L1). The first end of the second switch (Q1) is connected to the first voltage source, and the second end of the second switch (Q1) is electrically connected to the first end of the third switch (Q3) and one end of the inductor (L1). The second end of the third switch (Q3) is grounded, and the other end of the inductor (L1) is electrically connected to the positive terminal of the LED lamp (200).

6. The driving circuit (100) according to claim 5, characterized in that, The DC / DC circuit (110) also includes a fourth switch (Q2); The first terminal of the fourth switch (Q2) is connected to the first voltage source, the second terminal of the fourth switch (Q2) is electrically connected to the first terminal of the third switch (Q3) and one end of the inductor (L1), and the control terminal of the fourth switch (Q2) is electrically connected to the buck controller (U2).

7. The driving circuit (100) according to any one of claims 1-6, characterized in that, The dimming circuit (140) includes a second operational amplifier (U3), a fifth switching transistor (Q4), and a current sensing resistor (141). The second operational amplifier (U3) has a third input terminal, a fourth input terminal and a second output terminal. The third input terminal is electrically connected to the pulse width signal output terminal of the control module (130). The fourth input terminal is electrically connected to one end of the current sensing resistor (141) and the first end of the fifth switching transistor (Q4). The second output terminal is electrically connected to the control terminal of the fifth switching transistor (Q4). The second end of the fifth switching transistor (Q4) is electrically connected to the negative terminal of the LED lamp (200).

8. The driving circuit (100) according to claim 7, characterized in that, The dimming circuit (140) also includes a first resistor (142) and a second resistor (143); Wherein, one end of the first resistor (142) is electrically connected to the fourth input terminal and one end of the second resistor (143), the other end of the first resistor (142) is connected to the second voltage source, and the other end of the second resistor (143) is electrically connected to one end of the current sensing resistor (141) and the first end of the fifth switching transistor (Q4).

9. The driving circuit (100) according to claim 7, characterized in that, The driving circuit (100) also includes a conversion circuit (150); One end of the conversion circuit (150) is electrically connected to the pulse width signal output terminal of the control module (130), and the other end of the conversion circuit (150) is electrically connected to the third input terminal of the dimming circuit (140). The conversion circuit (150) is configured to convert the pulse width signal output by the control module (130) into an analog signal and input the analog signal into the dimming circuit (140).

10. A lighting device (10), characterized in that, Includes an LED lamp (200) and a driving circuit (100) according to any one of claims 1-9.

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