New LED driver for multi-channel/wide dimming ratio simplifies HDTV backlighting (Figure)

In order to enhance the advantages of LEDTV in regional dimming, the innovative LED driver will independently control the light intensity, color and contrast through multiple channels and wide dimming ratio to achieve the goal of simplifying HDTV backlight design. Become an emerging LED driver option in the industry. In order to enhance the advantages of LEDTV in regional dimming, the innovative LED driver will independently control the light intensity, color and contrast through multiple channels and wide dimming ratio to achieve the goal of simplifying HDTV backlight design. Become an emerging LED driver option in the industry.



With the market view of light-emitting diode (LED) drivers, the current driver for driving white LEDs accounts for about 50. These white LEDs are widely used in small display backlights for many handheld, battery-powered portable products, but Applications are relatively mature and do not have a high annual compound growth rate (CAGR) over the next five years. With the LED driver market view, the current driver for driving white LEDs is about 50. These white LEDs are widely used in the backlighting of small displays for many handheld, battery-powered portable products. However, this application is relatively mature and will not have a high annual compound growth rate (CAGR) in the next five years. In terms of LED lighting applications, the growth rate is much larger than the three largest market segments in the field of handheld backlighting. One is car headlight lighting, the other is large high-definition television (HDTV), and finally the general lighting. . In terms of LED lighting applications, the growth rate is much larger than the three largest market segments in the field of handheld backlighting. One is car headlight lighting, the other is large high-definition television (HDTV), and finally the general lighting. .



However, 2008 is a crucial year for the popularity of LEDs. However, 2008 is a crucial year for the popularity of LEDs. LEDs meet some of the key performance standards that will drive the extremely high growth of LED driver requirements, which are the key to driving LEDs in a variety of end applications. LEDs meet some of the key performance standards that will drive the extremely high growth of LED driver requirements, which are the key to driving LEDs in a variety of end applications.



Despite these significant advances, there is still room for improvement in terms of energy conversion efficiency, thermal management, and production costs, such as significant improvements in LED efficiency, resulting from the generation of light in the chip (100 lm/W). And the best way to extract light from the chip and its package. Despite these significant advances, there is still room for improvement in terms of energy conversion efficiency, thermal management, and production costs, such as significant improvements in LED efficiency, resulting from the generation of light in the chip (100 lm/W). And the best way to extract light from the chip and its package. Similarly, the sales price of 20 mA white LEDs has been greatly reduced. Similarly, the sales price of 20 mA white LEDs has been greatly reduced. When initially launched, the volume purchase price was $1. When initially launched, the volume purchase price was $1. Today, it is possible to purchase a 20 mA white LED with a purchase price of less than 20 cents. Today, it is possible to purchase a 20 mA white LED with a purchase price of less than 20 cents.



LEDTV replaces CCFLTV for the general trend LEDTV replaces CCFLTV for the general trend



HDTV is one of the fastest growing consumer electronics markets. In the past, large flat-panel TVs have been using CCFL backlighting. HDTV is one of the fastest growing consumer electronics markets. In the past, large flat-panel TVs have been using CCFL backlighting. However, in order to eliminate the need for toxic mercury vapor in CCFL lighting, while increasing efficiency and performance, LED backlighting has been pushed into new HDTV designs. However, in order to eliminate the need for toxic mercury vapor in CCFL lighting, while increasing efficiency and performance, LED backlighting has been pushed into new HDTV designs. In addition, as many governments have adopted new green measures to eliminate toxic materials such as mercury commonly used in CCFLs, this trend has also been encouraged. In addition, as many governments have adopted new green measures to eliminate toxic materials such as mercury commonly used in CCFLs, this trend has also been encouraged.



As consumers demand greater HDTV and higher resolution, the demand for televisions has rapidly shifted from high-quality plasma (PDP) to high-definition LCD TVs (LCDTVs). As consumers demand greater HDTV and higher resolution, the demand for televisions has rapidly shifted from high-quality plasma (PDP) to high-definition LCD TVs (LCDTVs). According to market research firm research, sales of high-quality PDP peaked in 2008, with revenues of approximately $24 billion, while high-definition LCD TVs have a market value of $75 billion and will grow to $93 billion by 2010. According to market research firm research, sales of high-quality PDP peaked in 2008, with revenues of approximately $24 billion, while high-definition LCD TVs have a market value of $75 billion and will grow to $93 billion by 2010. However, high-definition LCD TVs still have a number of shortcomings, ranging from fast moving image blurring to inaccurate color reproduction. However, high-definition LCD TVs still have a number of shortcomings, ranging from fast moving image blurring to inaccurate color reproduction. In the current HDTV, true black cannot be achieved, and the dynamic range of all colors has room for improvement. For example, a high-definition LCD TV can only provide a contrast ratio of 450 to 650 cd/m2. In the current HDTV, true black cannot be achieved, and the dynamic range of all colors has room for improvement. For example, a high-definition LCD TV can only provide a contrast ratio of 450 to 650 cd/m2. The main problem with these HDTVs is that they do not completely turn off CCFL backlighting or local dimming. The main problem with these HDTVs is that they do not completely turn off CCFL backlighting or local dimming.



Conversely, with high-brightness (HB) LED backlighting, an array of LEDs (up to 2,400 LEDs) can be divided into two hundred and forty separate dimming groups. Conversely, with high-brightness (HB) LED backlighting, an array of LEDs (up to 2,400 LEDs) can be divided into two hundred and forty separate dimming groups. Each group typically consists of eight to ten 30-50 mA LEDs, each of which can be individually dimmed through a single pin to provide local dimming. Each group typically consists of eight to ten 30-50 mA LEDs, each of which can be individually dimmed through a single pin to provide local dimming.



This design provides a single bit higher contrast ratio (] 4,000 cd/m2) than the CCFL design. This design provides a single bit higher contrast ratio (] 4,000 cd/m2) than the CCFL design. In addition, by adjusting the LED backlighting with a wide dimming ratio, more midtone colors can be reproduced, providing a more vivid picture.



Another benefit of being able to partially turn off the LEDs is to reduce motion blur. Another benefit of being able to partially turn off the LEDs is to reduce motion blur. By completely turning off the LEDs between the frames, the blurring of fast moving objects is almost completely eliminated. By completely turning off the LEDs between the frames, the blurring of fast moving objects is almost completely eliminated. In solving this fast motion blur problem encountered in CCFL backlighting high-definition LCD TVs, it is critical that LEDs respond quickly. In solving this fast motion blur problem encountered in CCFL backlighting high-definition LCD TVs, it is critical that LEDs respond quickly.



In order to make the local dimming design feasible, LED drivers with multiple channels and independent dimming with a very wide dimming ratio are required. In order to make the local dimming design feasible, LED drivers with multiple channels and independent dimming with a very wide dimming ratio are required. Fortunately, some power IC designers have anticipated this need. Fortunately, some power IC designers have anticipated this need.



Dimming must consider light intensity / color dimming to consider light intensity / color



LED dimming is typically accomplished by using a direct current (DC) signal or a filtered pulse width modulation (PWM) to regulate the forward current flowing through the LED. LED dimming is typically accomplished by using a direct current (DC) signal or a filtered pulse width modulation (PWM) to regulate the forward current flowing through the LED. Although reducing the LED current adjusts the LED light output intensity, the change in forward current also changes the color of the LED because the chromaticity of the LED varies with current. Although reducing the LED current adjusts the LED light output intensity, the change in forward current also changes the color of the LED because the chromaticity of the LED varies with current. Many applications, such as high-definition LCD TVs and automotive backlights, do not allow for any deviation in LED color. In these applications, a wide dimming range is required because of the different light variations in the environment and the small changes in light intensity by the human eye. Very sensitive. Many applications, such as high-definition LCD TVs and automotive backlights, do not allow for any deviation in LED color. In these applications, a wide dimming range is required because of the different light variations in the environment and the small changes in light intensity by the human eye. Very sensitive. The PWM signal is used to control the intensity of the LED, allowing the LED to be dimmed without changing its color. The PWM signal is used to control the intensity of the LED, allowing the LED to be dimmed without changing its color.



TrueColorPWM dimming dims the LED through a PWM signal. TrueColorPWM dimming dims the LED through a PWM signal. It essentially turns the LED on and off with full current at the PWM frequency. It essentially turns the LED on and off with full current at the PWM frequency. The human eye has a limit of 50 to 60 frames per second. For example, by increasing the PWM frequency to 100 Hz, the human eye will feel that the pulse source is continuously turned on. The human eye has a limit of 50 to 60 frames per second. For example, by increasing the PWM frequency to 100 Hz, the human eye will feel that the pulse source is continuously turned on. In addition, the intensity of the LED can be controlled by the modulation duty cycle (the length of the on time). In addition, the intensity of the LED can be controlled by the modulation duty cycle (the length of the on time). With this method, the color of the LED remains the same because the LED current value is either zero or a constant value. With this method, the color of the LED remains the same because the LED current value is either zero or a constant value. Many HDTV designers require a dimming ratio of more than 3,000:1 to accommodate a variety of ambient lighting conditions. Many HDTV designers require a dimming ratio of more than 3,000:1 to accommodate a variety of ambient lighting conditions.



Innovative LED Drivers Target HDTV Applications



The industry has developed a new and innovative LED driver specifically for HDTV, with its buck mode LED driver with sixteen individual channels, each capable of driving up to ten 50 mA LEDs from up to 45 volts of input. A set of LED strings, each channel can be used to drive a group of LEDs consisting of ten LEDs to provide local dimming. The industry has developed a new and innovative LED driver specifically for HDTV, with its buck mode LED driver with sixteen individual channels, each capable of driving up to ten 50 mA LEDs from up to 45 volts of input. A set of LED strings, each of which can be used to drive a group of LEDs consisting of ten LEDs to provide local dimming. Accordingly, each drive can drive up to one hundred and sixty 50 mA white LEDs. Accordingly, each drive can drive up to one hundred and sixty 50 mA white LEDs. A 46? capsule has æž°? About 18 drivers, each of its 16 channels can be independently controlled and has a separate PWM input with a PWM dimming ratio of up to 5,000:1. A 46? capsule has æž°? About 18 drivers, each of its 16 channels can be independently controlled and has a separate PWM input with a PWM dimming ratio of up to 5,000:1.



Only one tiny chip inductor and one more tiny ceramic output capacitor are required per channel. The only other components required are a single input capacitor and current setting resistor (Figure 1). Only one tiny chip inductor and one more tiny ceramic output capacitor are required per channel. The only other components required are a single input capacitor and current setting resistor (Figure 1). All sixteen channel clamp diodes, power switches and compensation control logic are compressed in the new 56-pin, 5mm x 9mm quad flat no-lead (QFN) package of the new LED driver. in. All sixteen channel clamp diodes, power switch and compensation control logic are compressed in the new LED driver with a small 56-pin, 5 mm × 9 mm quad flat no-lead (QFN) In the package.















Figure 1. A sixteen channel LED driver that drives one hundred and sixty 20 mA white LEDs from a 45 volt input. Figure 1. A sixteen channel LED driver that drives one hundred and sixty 20 mA white LEDs from a 45 volt input.



The new LED driver has a peak efficiency of 92 at 2MHz switching frequency (Figure 2), eliminating the need for an external heat sink. The new LED driver has a peak efficiency of 92 at 2MHz switching frequency (Figure 2), eliminating the need for an external heat sink. In addition, the 2MHz switching frequency significantly reduces the size of multiple inductors required for printed circuit boards (PCBs), thus allowing the use of very thin TV housings. In addition, the 2MHz switching frequency significantly reduces the size of multiple inductors required for printed circuit boards (PCBs), thus allowing the use of very thin TV housings. This is a key factor because most consumers want to install HDTVs on the walls of the living room, so for aesthetic reasons, a lightweight and slim form factor is required. This is a key factor because most consumers want to install HDTVs on the walls of the living room, so for aesthetic reasons, a lightweight and slim form factor is required.















Figure 1 Figure 1 shows that the efficiency of one hundred and sixty LED drivers is higher than 92. Figure 2 shows that the efficiency of one hundred and sixty LED drivers is higher than 92.



The new LED driver has a PWM dimming capability of up to 5,000:1. The new LED driver has a PWM dimming capability of up to 5,000:1. Figure 3 shows a 5,000:1 PWM dimming waveform and a very square LED current waveform. Figure 3 shows a 5,000:1 PWM dimming waveform and a very square LED current waveform. Even at an on-time of only 2 microseconds, the current of a 20 mA LED is turned on and off in synchronization with the 100 Hz PWM signal. Even at an on-time of only 2 microseconds, the current of a 20 mA LED is turned on and off in synchronization with the 100 Hz PWM signal. A higher PWM dimming ratio can be achieved with a lower PWM frequency, but 100Hz guarantees no visible flicker. A higher PWM dimming ratio can be achieved with a lower PWM frequency, but 100Hz guarantees no visible flicker.















Figure 3 shows the 5,000:1 pulse width modulated dimming waveform of the circuit of Figure 1. Figure 3 shows the 5,000:1 pulse width modulated dimming waveform of the circuit of Figure 1.



The full LED brightness of all sixteen channels is set by a single external resistor, each channel has the same programmed LED current (set between 10 and 50 mA), and the channel-to-channel LED current accuracy is within 8 . The full LED brightness of all sixteen channels is set by a single external resistor, each channel has the same programmed LED current (set between 10 and 50 mA), and the channel-to-channel LED current accuracy is within 8 . TrueColorPWM dimming provides accurate dimming with a reduced duty cycle, while the emitted light is free of any color shifts. The fixed frequency, current mode control circuitry provides stable operation over a wide range of input and output voltages and currents. TrueColorPWM dimming provides accurate dimming with a reduced duty cycle, while the emitted light is free of any color shifts. The fixed frequency, current mode control circuitry provides stable operation over a wide range of input and output voltages and currents. Each channel's LED current is controlled through an internal sense resistor, and each channel's internal switching and control circuitry provides LED-driven excellent constant current source regulation. Each channel's LED current is controlled through an internal sense resistor, and each channel's internal switching and control circuitry provides LED-driven excellent constant current source regulation. The internal 100 mA power switch and the 56-pin QFN package exposed thermal pad provide sufficient power and thermal management to handle sixteen channels of power and heat at 50 mA. The internal 100 mA power switch and the 56-pin QFN package exposed thermal pad provide sufficient power and thermal management to handle sixteen channels of power and heat at 50 mA.



LEDs have clearly become the mainstream choice for HDTV backlighting, but system designers still have to have LED drivers that meet specific design performance requirements. LEDs have clearly become the mainstream choice for HDTV backlighting, but system designers still have to have LED drivers that meet specific design performance requirements. Therefore, the LED driver must be able to meet the input voltage range, output voltage and current demand conversion architecture to provide sufficient current and voltage for different types of LED configurations. Therefore, the LED driver must be able to meet the input voltage range, output voltage and current demand conversion architecture to provide sufficient current and voltage for different types of LED configurations. Therefore, LED drivers must have the following features, such as a wide input voltage range, wide output voltage range, high efficiency conversion, tight adjustment of LED current matching, low noise and fixed frequency operation, independent current and dimming control, wide dimming ratio and Very few external components make up a small footprint solution to meet the designer's needs. Therefore, LED drivers must have the following features, such as a wide input voltage range, wide output voltage range, high efficiency conversion, tight adjustment of LED current matching, low noise and fixed frequency operation, independent current and dimming control, wide dimming ratio and A minimal footprint solution with minimal external components to meet the designer's needs.

Nano High-frequency Transformer Iron Core

Our company's high-frequency transformer iron cores have very good quality.It can be widely used to the Inverter Welding machine power supply,X-ray, laser, communication power supply,UPS and high frequency induction heating power supply ,charging power supply,electrolytic and electroplate power supply,frequency control of motor speed power supply and plasma cutting machine.

Power Transformer Magnetic Ring,Low-Cost Iron Core,Plasma Cutting Machine Iron Core,Heating Power Supply Core

Anyang Kayo Amorphous Technology Co.,Ltd. , https://www.kayoamotech.com