LED driving circuit with reverse negative pressure absorption

By designing an LED driver circuit with reverse negative voltage absorption function, the problem of LED damage caused by reverse voltage under PWM control was solved, and stable power supply and protection for LEDs were achieved.

CN224343416UActive Publication Date: 2026-06-09MYNICE OPTOELECTRONICS CO LTD
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Patent Information

Authority / Receiving Office
CN · China
Patent Type
Utility models(China)
Current Assignee / Owner
MYNICE OPTOELECTRONICS CO LTD
Filing Date
2025-04-10
Publication Date
2026-06-09

AI Technical Summary

Technical Problem

Existing LED driver circuits using PWM control suffer from LED damage due to excessive reverse voltage.

Method used

A circuit structure including input rectification and filtering, surge protection, power conversion, input overvoltage/undervoltage protection and PWM control was designed, and a reverse negative voltage absorption output circuit was set up to effectively convert the input power supply and limit the reverse voltage through multiple links.

Benefits of technology

It enables the LED to be supplied with stable current or voltage, protects the LED from reverse voltage interference, and improves the reliability and safety of the LED.

✦ Generated by Eureka AI based on patent content.

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Abstract

The utility model discloses a kind of LED drive circuit with reverse negative pressure absorption, mainly solve the problem that LED is damaged directly by excessively high reverse voltage when using PWM control in existing LED drive circuit. The LED drive circuit, including input rectification filter circuit, surge protection circuit, power conversion circuit and input overvoltage\undervoltage protection circuit connected with input rectification filter circuit, PWM control circuit connected with power conversion circuit and input overvoltage\undervoltage protection circuit, and reverse negative pressure absorption output circuit connected with PWM control circuit. The utility model limits the sudden change of current or voltage by setting reverse negative pressure absorption output circuit, protects element from the interference of reverse voltage, solves reverse voltage interference in circuit, significantly improves the reliability and security of LED.
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Description

Technical Field

[0001] This utility model belongs to the field of LED driving technology, specifically, it relates to an LED driving circuit with reverse negative voltage absorption. Background Technology

[0002] LEDs require a constant current or voltage to operate, but the input power supply (such as 220V AC or 12V DC) is often not directly compatible. The driver circuit converts the power supply into a voltage / current form suitable for the LED through rectification, buck / boost, and filtering.

[0003] In conventional PWM-controlled LED driver circuits, directly applying PWM dimming to the product can easily lead to reverse voltage. Prolonged reverse voltage can negatively impact the circuit, such as reducing LED lifespan; excessively high reverse voltage can even damage the LED. Utility Model Content

[0004] The purpose of this invention is to provide an LED driver circuit with reverse negative voltage absorption, which mainly solves the problem that in existing LED driver circuits using PWM control, excessive reverse voltage directly damages the LED.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] An LED driver circuit with reverse negative voltage absorption includes an input rectifier and filter circuit, a surge protection circuit, a power conversion circuit and an input overvoltage / undervoltage protection circuit connected to the input rectifier and filter circuit, a PWM control circuit connected to the power conversion circuit and the input overvoltage / undervoltage protection circuit, and a reverse negative voltage absorption output circuit connected to the PWM control circuit.

[0007] Furthermore, in this utility model, the input rectifier filter circuit includes a full-bridge rectifier D, a resistor R1 connected to the output terminal of the full-bridge rectifier D, an amplifier A1 whose non-inverting input terminal is connected to the other end of the resistor R1, an inductor L1 whose one end is connected to the inverting input terminal of the amplifier A1 and whose other end is grounded, and a capacitor C1 whose one end is connected to the non-inverting input terminal of the amplifier A1 and whose other end is grounded; wherein, the output terminal of the amplifier A1 serves as the output terminal of the input rectifier filter circuit and is connected to the power conversion circuit and the input overvoltage / undervoltage protection circuit, and the other output terminal of the full-bridge rectifier D is connected to the surge protection circuit.

[0008] Furthermore, in this utility model, the surge protection circuit includes operational amplifiers A2 and A3, both connected to the output terminal of the full-bridge rectifier D; a resistor R3 connected to the output terminal of operational amplifier A3; a transistor VT2 whose base is connected to the other end of resistor R3; a resistor R2 connected to the output terminal of operational amplifier A2; a transistor VT1 whose base is connected to the other end of resistor R2; a potentiometer VR1 whose sliding terminal is connected to the inverting input terminal of operational amplifier A2, with one fixed terminal connected to 12V and the other fixed terminal grounded; a potentiometer VR2 whose sliding terminal is connected to the non-inverting input terminal of operational amplifier A3, with one fixed terminal connected to 12V and the other fixed terminal grounded; a resistor R8 connected to the collector of transistor VT1; and a diode D1 connected in parallel across resistor R8. The emitter of transistor VT1 is connected to the collector of transistor VT2, the emitter of transistor VT2 is grounded, and the negative terminal of diode D1 connected in parallel with resistor R8 serves as the grounding terminal of the surge protection circuit.

[0009] Furthermore, in this utility model, the power conversion circuit includes a resistor R5 connected at one end to the output terminal of amplifier A1, a resistor R6, a capacitor C2, and a capacitor C3 connected to the other end of resistor R5, an operational amplifier A7 whose non-inverting input terminal is connected to the other end of capacitor C3, a resistor R7 connected at one end to the inverting input terminal of operational amplifier A7 and grounded at the other end, and resistors R8 and R9 connected at one end to the inverting input terminal of operational amplifier A7; wherein, the other ends of capacitor C2 and resistor R9 are grounded, and the other ends of resistors R6 and R8 are connected to the output terminal of operational amplifier A7; the output terminal of operational amplifier A7 serves as the output terminal of the power conversion circuit and is connected to the PWM control circuit.

[0010] Furthermore, in this utility model, the input overvoltage / undervoltage protection circuit includes a resistor R10 connected to the input rectifier filter circuit, an amplifier A4 whose non-inverting input terminal is connected to the other end of resistor R10, resistors R14 and R15 both connected to the output terminal of amplifier A4, a resistor R13 connected to the other end of resistor R14, a resistor R12 connected to the other end of resistor R13, an amplifier A5 whose non-inverting input terminal is connected to the common terminal of resistors R13 and R12 and whose output terminal is connected to the other end of resistor R12, and a resistor R... 11. Amplifier A6, whose inverting input is connected to the other end of resistor R15 and whose non-inverting input is connected to the other end of resistor R11; resistor R17, whose one end is connected to the inverting input of amplifier A6 and whose other end is connected to the output of amplifier A6; and resistor R16, whose one end is connected to the non-inverting input of amplifier A6 and whose other end is grounded; wherein, the inverting input of amplifier A4 is connected to the common terminal of resistors R13 and R14, the inverting input of amplifier A5 is connected to the comparison voltage VREF, and the output of amplifier A6 is used as the output of the overvoltage / undervoltage protection circuit.

[0011] Furthermore, in this utility model, the PWM control circuit includes a resistor R18 with one end connected to the output terminal of operational amplifier A7 in the power conversion circuit, a capacitor C4 with one end connected to the other end of resistor R18 and the other end connected to the output terminal of amplifier A6 in the overvoltage / undervoltage protection circuit, a diode D2 with its positive terminal connected to the output terminal of amplifier A6 and its negative terminal connected to the output terminal of operational amplifier A7, an electrolytic capacitor C5 with its positive terminal connected to the negative terminal of diode D2 and its negative terminal grounded, and a resistor R19 with one end connected to the negative terminal of diode D2 and the other end connected to the reverse negative voltage absorption output circuit; wherein, the positive terminal of electrolytic capacitor C5 is connected to VCC and the reverse negative voltage absorption output circuit.

[0012] Furthermore, in this invention, the reverse negative voltage absorption output circuit is composed of a capacitor C6 and a power resistor R20 connected in parallel across the load LED; wherein, the two ends of the capacitor C6 are respectively connected to the other end of the resistor R19 and the positive terminal of the electrolytic capacitor C5.

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] (1) The LED driver circuit of this utility model achieves effective conversion of the input power supply through rectification and filtering, surge protection, power conversion, input overvoltage / undervoltage protection and PWM control, providing the LED with a constant current or voltage. At the same time, by setting up a reverse negative voltage absorption output circuit to limit the sudden change of current or voltage, the components are protected from reverse voltage interference, and the reverse voltage interference in the circuit is solved, which significantly improves the reliability and safety of the LED.

[0015] (2) After the AC power supply is connected, the power supply is rectified by the full-bridge rectifier D and filtered by the resistor R1, inductor L1 and capacitor C1 to obtain a relatively stable DC voltage. The voltage is further adjusted by the power conversion circuit and then the PWM control circuit is used for precise dimming control, thereby avoiding damage to the circuit and LED by reverse voltage. Attached Figure Description

[0016] Figure 1 This is the circuit schematic diagram of this utility model. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments. The embodiments of the present invention include, but are not limited to, the following embodiments.

[0018] Example

[0019] like Figure 1 As shown, this utility model discloses an LED driver circuit with reverse negative voltage absorption, including an input rectifier and filter circuit, a surge protection circuit, a power conversion circuit, and an input overvoltage / undervoltage protection circuit connected to the input rectifier and filter circuit, a PWM control circuit connected to the power conversion circuit and the input overvoltage / undervoltage protection circuit, and a reverse negative voltage absorption output circuit connected to the PWM control circuit. This circuit, through rectification and filtering, surge protection, power conversion, input overvoltage / undervoltage protection, and PWM control, achieves effective conversion of the input power supply, providing a constant current or voltage to the LED. Simultaneously, by setting up the reverse negative voltage absorption output circuit, it limits sudden changes in current or voltage, protecting the components from reverse voltage interference and solving the reverse voltage interference problem in the circuit.

[0020] In this embodiment, the input rectifier and filter circuit includes a full-bridge rectifier D, a resistor R1 connected to the output terminal of the full-bridge rectifier D, an amplifier A1 whose non-inverting input terminal is connected to the other end of the resistor R1, an inductor L1 whose one end is connected to the inverting input terminal of the amplifier A1 and the other end is grounded, and a capacitor C1 whose one end is connected to the non-inverting input terminal of the amplifier A1 and the other end is grounded. The output terminal of the amplifier A1 serves as the output terminal of the input rectifier and filter circuit and is connected to the power conversion circuit and the input overvoltage / undervoltage protection circuit. The other output terminal of the full-bridge rectifier D is connected to the surge protection circuit. After the AC power supply is connected, the power is rectified by the full-bridge rectifier D and filtered by the resistor R1, inductor L1, and capacitor C1 to obtain a relatively stable DC voltage.

[0021] In this embodiment, the surge protection circuit includes operational amplifiers A2 and A3, both connected to the output terminal of the full-bridge rectifier D; a resistor R3 connected to the output terminal of operational amplifier A3; a transistor VT2 whose base is connected to the other end of resistor R3; a resistor R2 connected to the output terminal of operational amplifier A2; a transistor VT1 whose base is connected to the other end of resistor R2; a potentiometer VR1 whose sliding terminal is connected to the inverting input terminal of operational amplifier A2, with one fixed terminal connected to 12V and the other fixed terminal grounded; a potentiometer VR2 whose sliding terminal is connected to the non-inverting input terminal of operational amplifier A3, with one fixed terminal connected to 12V and the other fixed terminal grounded; a resistor R8 connected to the collector of transistor VT1; and a diode D1 connected in parallel across resistor R8. The emitter of transistor VT1 is connected to the collector of transistor VT2, the emitter of transistor VT2 is grounded, and the negative terminal of diode D1 connected in parallel with resistor R8 serves as the ground terminal of the surge protection circuit. By setting up a surge protection circuit, the impact on LEDs can be effectively avoided when sudden spikes in current or voltage occur in the power supply circuit due to the instability of AC power.

[0022] In this embodiment, the power conversion circuit includes a resistor R5 connected at one end to the output terminal of amplifier A1, a resistor R6, a capacitor C2, and a capacitor C3 connected to the other end of resistor R5, an operational amplifier A7 whose non-inverting input terminal is connected to the other end of capacitor C3, a resistor R7 connected at one end to the inverting input terminal of operational amplifier A7 and grounded at the other end, and resistors R8 and R9 connected at one end to the inverting input terminal of operational amplifier A7; wherein, the other ends of capacitor C2 and resistor R9 are grounded, and the other ends of resistors R6 and R8 are connected to the output terminal of operational amplifier A7; the output terminal of operational amplifier A7 serves as the output terminal of the power conversion circuit and is connected to the PWM control circuit. This circuit further adjusts the power supply voltage.

[0023] In this embodiment, the input overvoltage / undervoltage protection circuit includes a resistor R10 connected to the input rectifier filter circuit; an amplifier A4 whose non-inverting input terminal is connected to the other end of resistor R10; resistors R14 and R15 connected to the output terminal of amplifier A4; a resistor R13 connected to the other end of resistor R14; a resistor R12 connected to the other end of resistor R13; an amplifier A5 whose non-inverting input terminal is connected to the common terminal of resistors R13 and R12 and whose output terminal is connected to the other end of resistor R12; a resistor R11 connected to the output terminal of amplifier A5; and an inverting resistor R11. Amplifier A6 has its inverting input connected to the other end of resistor R15 and its non-inverting input connected to the other end of resistor R11. Resistor R17 has one end connected to the inverting input of amplifier A6 and the other end connected to the output of amplifier A6. Resistor R16 has one end connected to the non-inverting input of amplifier A6 and the other end grounded. The inverting input of amplifier A4 is connected to the common terminal of resistors R13 and R14. The inverting input of amplifier A5 is connected to the comparison voltage VREF. The output of amplifier A6 serves as the output of an overvoltage / undervoltage protection circuit. The input overvoltage / undervoltage protection circuit monitors the input voltage to prevent excessively high or low voltage from affecting the circuit.

[0024] In this embodiment, the PWM control circuit includes a resistor R18 connected at one end to the output of operational amplifier A7 in the power conversion circuit; a capacitor C4 connected at one end to the other end of resistor R18 and at the other end to the output of amplifier A6 in the overvoltage / undervoltage protection circuit; a diode D2 with its positive terminal connected to the output of amplifier A6 and its negative terminal connected to the output of operational amplifier A7; an electrolytic capacitor C5 with its positive terminal connected to the negative terminal of diode D2 and its negative terminal grounded; and a resistor R19 connected at one end to the negative terminal of diode D2 and at the other end to the reverse negative voltage absorption output circuit. The positive terminal of electrolytic capacitor C5 is connected to VCC and the reverse negative voltage absorption output circuit. The reverse negative voltage absorption output circuit consists of a capacitor C6 connected in parallel across the load LED and a power resistor R20. The two ends of capacitor C6 are connected to the other end of resistor R19 and the positive terminal of electrolytic capacitor C5, respectively. This circuit limits sudden changes in current or voltage by connecting a power resistor in parallel across the LED load, protecting the component from reverse voltage interference and resolving reverse voltage interference in the drive circuit.

[0025] The above embodiments are merely one of the preferred embodiments of this utility model and should not be used to limit the scope of protection of this utility model. Any modifications or refinements made to the main design concept and spirit of this utility model that are not of substantial significance, but solve the same technical problem as this utility model, should be included within the scope of protection of this utility model.

Claims

1. An LED driving circuit with reverse negative voltage absorption, characterized in that, It includes an input rectifier and filter circuit, a surge protection circuit, a power conversion circuit, and an input overvoltage / undervoltage protection circuit connected to the input rectifier and filter circuit, a PWM control circuit connected to the power conversion circuit and the input overvoltage / undervoltage protection circuit, and a reverse negative voltage absorption output circuit connected to the PWM control circuit.

2. The LED driving circuit with reverse negative voltage absorption according to claim 1, characterized in that, The input rectifier and filter circuit includes a full-bridge rectifier D, a resistor R1 connected to the output terminal of the full-bridge rectifier D, an amplifier A1 whose non-inverting input terminal is connected to the other end of the resistor R1, an inductor L1 whose one end is connected to the inverting input terminal of the amplifier A1 and the other end is grounded, and a capacitor C1 whose one end is connected to the non-inverting input terminal of the amplifier A1 and the other end is grounded; wherein, the output terminal of the amplifier A1 serves as the output terminal of the input rectifier and filter circuit and is connected to the power conversion circuit and the input overvoltage / undervoltage protection circuit, and the other output terminal of the full-bridge rectifier D is connected to the surge protection circuit.

3. The LED driving circuit with reverse negative voltage absorption according to claim 2, characterized in that, The surge protection circuit includes operational amplifiers A2 and A3, both connected to the output terminal of the full-bridge rectifier D; a resistor R3 connected to the output terminal of operational amplifier A3; a transistor VT2 whose base is connected to the other end of resistor R3; a resistor R2 connected to the output terminal of operational amplifier A2; a transistor VT1 whose base is connected to the other end of resistor R2; a potentiometer VR1 whose sliding terminal is connected to the inverting input terminal of operational amplifier A2, with one fixed terminal connected to 12V and the other fixed terminal grounded; a potentiometer VR2 whose sliding terminal is connected to the non-inverting input terminal of operational amplifier A3, with one fixed terminal connected to 12V and the other fixed terminal grounded; a resistor R8 connected to the collector of transistor VT1; and a diode D1 connected in parallel across resistor R8. The emitter of transistor VT1 is connected to the collector of transistor VT2, the emitter of transistor VT2 is grounded, and the negative terminal of diode D1 connected in parallel with resistor R8 serves as the ground terminal of the surge protection circuit.

4. The LED driving circuit with reverse negative voltage absorption according to claim 3, characterized in that, The power conversion circuit includes a resistor R5 connected at one end to the output terminal of amplifier A1, a resistor R6, a capacitor C2, and a capacitor C3 connected at the other end of resistor R5, an operational amplifier A7 whose non-inverting input terminal is connected to the other end of capacitor C3, a resistor R7 connected at one end to the inverting input terminal of operational amplifier A7 and grounded at the other end, and resistors R8 and R9 connected at one end to the inverting input terminal of operational amplifier A7; wherein, the other ends of capacitor C2 and resistor R9 are grounded, and the other ends of resistors R6 and R8 are connected to the output terminal of operational amplifier A7; the output terminal of operational amplifier A7 serves as the output terminal of the power conversion circuit and is connected to the PWM control circuit.

5. The LED driving circuit with anti-negative voltage absorption according to claim 4, characterized in that, The input overvoltage / undervoltage protection circuit includes a resistor R10 connected to the input rectifier filter circuit; an amplifier A4 whose non-inverting input terminal is connected to the other end of resistor R10; resistors R14 and R15 connected to the output terminals of amplifier A4; a resistor R13 connected to the other end of resistor R14; a resistor R12 connected to the other end of resistor R13; an amplifier A5 whose non-inverting input terminal is connected to the common terminal of resistors R13 and R12 and whose output terminal is connected to the other end of resistor R12; a resistor R11 connected to the output terminal of amplifier A5; and an inverting input... Amplifier A6 has its input terminal connected to the other end of resistor R15 and its non-inverting input terminal connected to the other end of resistor R11. Resistor R17 has one end connected to the inverting input terminal of amplifier A6 and the other end connected to the output terminal of amplifier A6. Resistor R16 has one end connected to the non-inverting input terminal of amplifier A6 and the other end grounded. Amplifier A4's inverting input terminal is connected to the common terminal of resistors R13 and R14. Amplifier A5's inverting input terminal is connected to the comparison voltage VREF. Amplifier A6's output terminal serves as the output terminal of the overvoltage / undervoltage protection circuit.

6. The LED driving circuit with reverse negative voltage absorption according to claim 5, characterized in that, The PWM control circuit includes a resistor R18 connected at one end to the output terminal of operational amplifier A7 in the power conversion circuit, a capacitor C4 connected at one end to the other end of resistor R18 and at the other end to the output terminal of amplifier A6 in the overvoltage / undervoltage protection circuit, a diode D2 with its positive terminal connected to the output terminal of amplifier A6 and its negative terminal connected to the output terminal of operational amplifier A7, an electrolytic capacitor C5 with its positive terminal connected to the negative terminal of diode D2 and its negative terminal grounded, and a resistor R19 connected at one end to the negative terminal of diode D2 and at the other end to the reverse negative voltage absorption output circuit; wherein, the positive terminal of electrolytic capacitor C5 is connected to VCC and the reverse negative voltage absorption output circuit.

7. The LED driving circuit with reverse negative voltage absorption according to claim 6, characterized in that, The reverse negative voltage absorption output circuit consists of a capacitor C6 and a power resistor R20 connected in parallel across the load LED; wherein, the two ends of the capacitor C6 are respectively connected to the other end of the resistor R19 and the positive terminal of the electrolytic capacitor C5.