Choose suitable high-efficiency driver solutions for different DC-DC LED lighting applications
In recent years, the application fields of high-brightness LEDs have been increasing, covering a wide range from mobile device backlights, medium and large-size LCD backlights, automotive interior and exterior lighting, and general lighting. Common DC-DC” title=”DC-DC”>DC-DC LED lighting” title=”LED lighting”>LED lighting applications include landscape lighting, internal low-voltage road lighting, solar powered lighting, automotive lighting, emergency vehicle lighting, ships Application, low-voltage halogen substitution and aircraft interior lighting, etc. This article will focus on how to choose suitable ON Semiconductor high-efficiency drivers for different DC-DC LED lighting applications. “title=”Driver”>Driver solutions.
Table 1: Common DC-DC LED lighting applications
LED DC-DC switching regulator topology
According to the relationship between input voltage and output voltage, we can divide the topological structure of LED DC-DC switching regulators into the following types:
Depressurization:It is suitable for applications where the minimum input voltage is always higher than the maximum voltage of the LED string under all operating conditions. For example, use this topology when driving a single 1 W LED with a 12 V power supply.
Boost:It is suitable for applications where the maximum input voltage is always lower than the minimum voltage of the LED string under all operating conditions. For example, use this topology when driving 6 LEDs with a 5 V power supply.
Buck-boost, or single-ended primary inductance converter (SEPIC):It is suitable for applications where the input voltage and output voltage overlap. For example, this topology can be used when driving 4 LEDs with a 12 V car battery.
Different topological structures are suitable for different LED driver solutions. As the premier supplier of high-performance silicon solutions for high-efficiency Electronic products, ON semiconductor uses the company’s expertise and expertise in power management to provide a wide range of high-efficiency driver solutions for various LED lighting applications. Including various high-efficiency DC-DC LED lighting solutions.
In recent years, the application fields of high-brightness LEDs have been increasing, covering a wide range from mobile device backlights, medium and large-size LCD backlights, automotive interior and exterior lighting, and general lighting. Common DC-DC LED lighting applications include landscape lighting, internal low-voltage road lighting, solar-powered lighting, automotive lighting, emergency vehicle lighting, marine applications, low-voltage halogen substitution, and aircraft interior lighting. This article will focus on how to select suitable ON Semiconductor high-efficiency driver solutions for different DC-DC LED lighting applications.
Table 1: Common DC-DC LED lighting applications
LED DC-DC switching regulator topology
According to the relationship between input voltage and output voltage, we can divide the topological structure of LED DC-DC switching regulators into the following types:
Depressurization:It is suitable for applications where the minimum input voltage is always higher than the maximum voltage of the LED string under all operating conditions. For example, use this topology when driving a single 1 W LED with a 12 V power supply.
Boost:It is suitable for applications where the maximum input voltage is always lower than the minimum voltage of the LED string under all operating conditions. For example, use this topology when driving 6 LEDs with a 5 V power supply.
Buck-boost, or single-ended primary inductance converter (SEPIC):It is suitable for applications where the input voltage and output voltage overlap. For example, this topology can be used when driving 4 LEDs with a 12 V car battery.
Different topological structures are suitable for different LED driver solutions. As the premier supplier of high-performance silicon solutions for high-efficiency electronic products, ON Semiconductor uses the company’s expertise and expertise in power management to provide a wide range of high-efficiency driver solutions for various LED lighting applications. Including various high-efficiency DC-DC LED lighting solutions.
LED DC-DC step-down driver solution
Typical LED DC-DC step-down applications include high-brightness modular light strips used in trunking lights, bookshelf lights and Display cabinet lights. Generally, each (11.5 x 1 inch) 4 LEDs, according to different colors, light effects It is 23 to 47 lm/W, and the voltage is 23 to 25 V.
Depending on the frequency and current, ON Semiconductor can be used in such applications to provide different LED DC-DC step-down driver solutions, including NCL30100 controller, CAT4201 regulator, and NCP3065/ which can be configured as a step-down regulator. NCV3065, NCP3066/NCV3066 regulators and controllers, etc. (see Figure 1). Each of these programs has its own characteristics.
Figure 1: Different LED DC-DC step-down driver solutions.
For example, NCL30100 does not integrate FETs as a controller, but it supports the use of cost-effective N-channel MOSFETs as external components, which can regulate current and work with a 100% duty cycle. However, the power supply voltage (VCC) of this component can reach 18 V, an external component is required to support a higher voltage, and it needs to be designed for a certain number of LEDs. NCL30100 is suitable for applications such as MR16 bulbs, 12 V landscape lighting, solar powered LED lighting, linear lighting, billboard text circuits and sign backlighting.
Figure 2: Basic application circuit diagram of NCL30100 LED step-down controller.
CAT4201 is a complete power converter that integrates MOSFET switches. It adopts a small TSOT5 package and has a maximum voltage of 36 Vdc (withstands 40 V instantaneous voltage). It can drive 7 serial LEDs with a total voltage of 32 V. The power efficiency is as high as 94%. , Provide current limiting and thermal protection. However, this component requires output capacitance in most applications, and the LED output current is limited to a maximum of 350 mA. CAT4201 is suitable for 12 V and 24 V lighting systems, automotive and aircraft lighting and general lighting applications.
Figure 3: Typical application circuit diagram of CAT4201 LED step-down driver.
NCP3065 and NCP3066, as well as the corresponding automotive-certified versions NCV3065 and NCV3066, are flexible switching regulators that can be configured in different structures such as buck, boost, and buck-boost. When configured as an LED buck regulator, it can work without using a large output capacitor. It supports a typical peak switching current of +40 V/1.5 A, and can set different output currents such as 350 mA, 700 mA, and 1,000 mA. It can also meet the needs of dimming. NCP3065/6, NCV3065/6 are suitable for automotive and ship lighting, high-power LED drivers, constant current sources, low-voltage LED lighting (landscape, road, solar and MR16 replacement) applications.
Figure 4: NCP3065 typical LED step-down application circuit (left) and typical LED step-up application circuit (right).
LED DC-DC boost driver solution
As mentioned above, NCP3065/6 and NCV3065/6 can be configured in different structures. The right of Figure 4 shows the application circuit diagram that is configured as a boost structure.
In addition, ON Semiconductor will also introduce the NCL30131 LED boost driver specifically for high-efficiency boost mode, suitable for driving long strings of high-brightness LEDs. NCL30131 is a switching boost controller that can use N-channel FETs and can be used to build energy-efficient LED boost drivers. This component uses a voltage mode pulse width modulation (PWM) feedback mechanism with an operational transconductance amplifier (OTA). This component has high drive capability and can drive high current/high energy efficiency MOSFETs. The input voltage range is extremely wide, between 4.5 V and 28 V. NCL30131 provides 300/600/1,000 kHz switching frequency, provides programmable current limit, short circuit protection, thermal shutdown, overvoltage protection and undervoltage lockout and other rich protection functions, suitable for MR16 building lighting, light bars, landscape lighting and cabinets Lighting and other applications.
Figure 5: Typical circuit diagram of NCL30131 high-efficiency boost LED driver.
Tests on the +12 Vin @ ~700 mA demo board based on NCL30131 that drives 10 high-brightness LEDs show that the energy efficiency is higher than 90%, and the line voltage regulation accuracy is less than 0.2%.
In addition to NCL30131, ON Semiconductor also provides another LED DC-DC boost converter-CAT4240. This component operates with a fixed switching frequency of 1 MHz and can use small external ceramic capacitors and inductors. The high-voltage output section of this component is very suitable for driving medium-sized and large-sized panel displays containing up to 10 serial white LEDs, with an energy efficiency of up to 94%.
LED DC-DC buck-boost driver solution
Typical LED buck-boost applications include driving a module containing 3 to 4 LEDs with a 12 V AC or 12 V DC power supply. In this application, the NCP3065/6 controller configured as a buck-boost topology can be used to meet the application requirements where the input voltage and the output voltage overlap. Figure 6 shows the circuit diagram of NCP3065 in such applications.
Figure 6: NCP3065 LED buck-boost application circuit diagram.
GreenPoint® online design simulation tool accelerates DC-DC LED lighting design
As the premier supplier of high-performance silicon solutions for high-efficiency electronic products, ON Semiconductor provides complete system solutions for various LED lighting applications (including DC-DC LED lighting applications), including power supplies, communications, light sensors, MOSFET, rectifier, protection, filter and thermal management products, etc.
In addition, in order to help designers speed up LED lighting design, ON Semiconductor also provides GreenPoint® online design simulation tools, allowing designers to sit in front of the workbench, that is, to easily select LED drivers, determine design requirements, Several steps such as “automatically generating design circuit diagrams”, “simulation and verification”, “generating bills of materials and reports”, “downloading reports as PDF files” and “saving files and sharing” greatly shorten the development time and speed up the product launch process.
This online design tool currently supports the application design of a variety of ON Semiconductor’s energy-efficient LED driver products. The supported DC-DC LED drivers include NCP3065, NCP3066, NCL30100, CAT4201, NCP1529 (buck solution), NCP5030 (buck -Boost scheme) and NCP5050 (boost scheme), etc. More products will be supported in the future.
Figure 7: ON Semiconductor GreenPoint® online design tool helps speed up LED lighting design.
Summarize
As the premier supplier of high-performance silicon solutions for high-efficiency electronic products, ON Semiconductor provides different high-efficiency DC-DC LED lighting products for users to choose according to their application requirements. ON Semiconductor also provides online analog design tools, demo boards, and a variety of reference designs to illustrate that customers can simplify the design and use of the bid. The design of ON Semiconductor’s LED driver products continues to trend towards small size, high energy efficiency and low cost, helping to promote the continuous development of the LED lighting market.