New LED Driver for Multi-channel / width ratio of simplifying HDTV backlight dimming

LED TV in the region to strengthen the advantage of dimming and OP113F datasheet and innovative LED driver to have multiple channels and OP113F price and through a wide dimming ratio of independent dimming, to control the light intensity, color and OP113F suppliers and contrast can be achieved by simplifying HDTV Backlight design goal, as the emerging LED industry, the drive options. To strengthen the local dimming LED TV advantage of innovative LED driver to have multiple channels and through a wide dimming ratio of independent dimming, to control the light intensity, color and contrast can be achieved by simplifying the design of the target backlight HDTV as the emerging LED industry drive options.

To light-emitting diode (LED) driver market perspective, the current used to drive white LED drive about 50%, which is widely used in many white LED handheld, battery powered portable products to the small display on the back lighting, but the applications are relatively mature in the next 5 years will not have a high compound annual growth rate (CAGR). The light-emitting diode (LED) driver market perspective, the current used to drive white LED drive about 50%, these white LED widely used in many handheld, battery-powered portable products of the small display on the back lighting, but this application is relatively mature in the next 5 years will not have a high compound annual growth rate (CAGR). For LED lighting applications, the growth rate is much larger than the area of handheld backlight in the three largest market segments, one for car headlights lighting, addition of large high-definition television (HDTV), the last is the general lighting . For LED lighting applications, the growth rate is much larger than the area of handheld backlight in the three largest market segments, one for car headlights lighting, addition of large high-definition television (HDTV), the last is the general lighting .

However, the popularity of LED, the 2008 is crucial year. However, the popularity of LED, the 2008 is crucial year. LED key performance criteria to meet the requirements, this will drive the demand for LED driver very high growth, LED driver is driving in a variety of end applications in the LED elements. LED key performance criteria to meet the requirements, this will drive the demand for LED driver very high growth, LED driver is driving in a variety of end applications in the LED elements.

Despite these significant advances, but on the energy conversion efficiency, thermal management and production cost, there is still room for improvement, such as LED efficiency has been a marked improvement, these progress from the chip to generate light (> 100 lm / W), and from the chip and its package to extract the best way to light. Despite these significant advances, but on the energy conversion efficiency, thermal management and production cost, there is still room for improvement, such as LED efficiency has been significant progress, these advances have come from the chip to generate light (> 100 lm / W ), and from the chip and its package to extract the best way to light. Similarly, 20 mg An Baiguang LED sales price has been greatly reduced. Similarly, 20 mg An Baiguang LED sales price has been greatly reduced. Was first introduced, the amount of purchase offer for 1 dollar. Was first introduced, the amount of purchase offer for 1 dollar. Today, there may be less than the amount of the purchase price of 20 cents, you can buy 20 mA white LED. Today, there may be less than the amount of the purchase price of 20 cents, you can buy 20 mA white LED. Replace the CCFL TV

LED TV LED TV for the trend to replace CCFL TV is the trend

HDTV is the highest growth markets in consumer electronics, flat screen TV has been used previously in large cold-cathode fluorescent lamp (CCFL) backlight. HDTV is the highest growth markets in consumer electronics, flat screen TV has been used previously in large cold-cathode fluorescent lamp (CCFL) backlight. However, the CCFL for the elimination of toxic mercury vapor lighting, while improving efficiency and performance requirements, has been promoting the new LED backlight into HDTV designs. However, the CCFL for the elimination of toxic mercury vapor lighting, while improving efficiency and performance requirements, has been promoting the new LED backlight into HDTV designs. In addition, many governments have adopted new green measures to eliminate the commonly used CCFL mercury and other toxic materials, is also contributing to this trend. In addition, many governments have adopted new green measures to eliminate the mercury commonly used CCFL and other toxic materials, is also contributing to this trend.

HDTV as consumers need more and higher resolution, on demand TV has been rapidly from high-definition plasma (PDP) shift to high art Quality LCD TV (LCD TV). As consumers demand more and higher-resolution HDTV, on demand TV has been rapidly from high-definition plasma (PDP) shifted to high-definition LCD TV (LCD TV). According to market research company research, high-definition PDP sales peaked in 2008, revenue was approximately $ 24,000,000,000, while the high-definition LCD TV with about 750 billion market value, to 2010 will grow to 930 billion U.S. dollars. According to market research company research, high-definition PDP sales peaked in 2008, revenue was approximately $ 24,000,000,000, while the high-definition LCD TV with about 750 billion market value, to 2010 will grow to 930 billion U.S. dollars. However, the high-definition LCD TV has many drawbacks, including the blurring from fast motion to the color reproduction is not accurate and so on. However, the high-definition LCD TV has many drawbacks, including the blurring from fast motion to the color reproduction is not accurate and so on. HDTV on the current terms, can not achieve true black, but the dynamic range of all colors have room for improvement, such as high-definition LCD TVs can only provide 450 ~ 650cd/m2 contrast. HDTV on the current terms, can not achieve true black, but the dynamic range of all colors have room for improvement, such as high-definition LCD TVs can only provide 450 ~ 650cd/m2 contrast. The main problem is that HDTV they can not completely shut down or its CCFL backlight local dimming. The main problem is that HDTV they can not completely shut down or its CCFL backlight local dimming.

The contrary, the use of high-brightness (HB) LED backlighting, an LED array (55-inch display on, there are as many as two thousand four hundred LED) can be divided into two hundred and forty separate dimming group. On the contrary, with high brightness (HB) LED backlighting, a LED array (55-inch display on, there are as many as two thousand four hundred LED) can be divided into two hundred and forty separate dimming group. Each group is usually eight to ten 30 to 50 mA LED, each group independently through a single pin dimming to provide local dimming. Each group is usually eight to ten 30 to 50 mA LED, each group independently through a single pin dimming to provide local dimming. This design provides almost

than the median level of a CCFL design of high contrast (> 4,000 cd/m2). This design provides an almost higher than the median level CCFL design the contrast (> 4,000 cd/m2). In addition, through the wide group of dimming LED backlighting than regulation, can reproduce colors more mid-tones, thus providing a more vivid picture. Able to partially close the LED

Another benefit is the ability to reduce the motion blur phenomenon. Able to partially close the LEDs another advantage is the ability to reduce the motion blur phenomenon. Completely through the frame off between the LED, almost completely eliminate the fast-moving objects ambiguity. Completely through the frame off between the LED, almost completely eliminate the fast-moving objects ambiguity. CCFL backlight in solving high-definition LCD TV experience this rapid motion blur problem, LED able to respond quickly is the key. CCFL backlight in solving high-definition LCD TV experience this rapid motion blur problem, LED Can quick response is key.

Designed to allow local dimming feasible, need to have multiple channels, to a very wide dimming ratio of independent dimming LED driver. To enable local dimming design is feasible, need to have multiple channels, to a very wide dimming ratio of independent dimming LED driver. Fortunately, some of the power IC designers have anticipated this need. Fortunately, some of the power IC designers have anticipated this need.

Dimming intensity to be considered / color dimming light intensity to be considered / color

LED dimming is usually through the use of a DC (DC) signal or a filtered pulse width modulation (PWM) regulator LED forward current flowing through to completion. LED dimming is usually through the use of a DC (DC) signal or a filtered pulse width modulation (PWM) regulator LED forward current flowing through to completion. Although the lower LED current can be adjusted LED light output intensity, but changes in forward current LED color will change, because with the current and the LEDs color change. Although the lower LED current can be adjusted LED light output intensity, but changes in forward current LED color will change, because with the current and the LEDs color change. Many applications such as high-definition LCD TVs and automotive color LED backlighting does not allow any deviation in these applications, requiring a wide dimming range, because the environment changes in a different light, and the human eye to small changes in light intensity are very sensitive. Many applications such as high-definition LCD TVs and automotive color LED backlighting does not allow any deviation in these applications, requiring a wide dimming range, because the environment changes in a different light, and the human eye to small changes in light intensity are very sensitive. Through a PWM signal to control LED intensity, allowing for LED dimming without changing its color. Through a PWM signal to control LED intensity, allowing for LED dimming without changing its color.

True Color PWM dimming of the LED through a PWM dimming signal. True Color PWM dimming of the LED through a PWM dimming signal. It is the PWM frequency is essentially turn on and off over current LED. It is the PWM frequency is essentially turn on and off over current LED. Human eye has fifty to sixty frames per second, the restrictions, such as through the PWM frequency up to 100Hz, the human eye will feel the pulse light source is a continuous conduction. Human eye has fifty to sixty frames per second, the restrictions, such as through the PWM frequency up to 100Hz, the human eye will feel the pulse light source is a continuous conduction. In addition through the modulation duty cycle (on-the length of time), can control the LEDs light intensity. In addition through the modulation duty cycle (on-the length of time), can control the LEDs light intensity. When using this method, LED color remains the same, because the LED current value, or zero, or to a constant value. When using this method, LED color remains the same, because the LED current value, or zero, or to a constant value. HDTV designers need a lot of dimming ratio of 3,000:1 or more, to accommodate a variety of ambient lighting conditions. HDTV designers need a lot of dimming ratio of 3,000:1 or more, to accommodate a variety of ambient lighting conditions.

Innovative LED driver applications targeting HDTV

Industry has developed specifically for HDTV new innovative LED drivers, the buck mode LED driver has sixteen separate channels, each up to 45 from volt input drive a string of up to 50 mA LED composed of ten LED strings, each channel can be used to drive the LED from the group consisting of ten LED to provide local dimming. Industry has developed specifically for HDTV new innovative LED driver, the buck mode LED driver has sixteen separate channels, each up to 45 volts from the input-driven string of up to ten 50 mA LED composed of LED strings, each channel can be used to drive the LED from the group consisting of ten LED to provide local dimming. So, each drive can be driven up to one hundred and sixty 50 mA white LED. So, each drive can be driven up to one hundred and sixty 50 mA white LED. A 46-inch LCD TV takes about eighteen drives, sixteen channels each can be independently controlled, and has a separate PWM input, this feature up to the PWM dimming ratio of 5,000:1. A 46-inch LCD TV takes about eighteen drive, its sixteen channels can be independently controlled for each, and has a separate PWM input, this has up to the PWM dimming ratio of 5,000:1.

Per channel requires only a tiny slice of a tiny inductor and a more ceramic output capacitors, the only other components required for a single input capacitor with the current setting resistor (Figure 1). Each channel requires only a tiny slice of a tiny inductor and a more ceramic output capacitors, the only other components required for a single input capacitor with the current set resistor (Figure 1). All sixteen channels of clamping diodes, power switch and a compensation function of the control logic is compressed in the new LED driver Fifty-six smaller pin, 5 mm × 9 Hao Mi quad flat no lead (QFN) package of in. All sixteen channels of clamp diodes, power switch and a compensation function of the control logic is compressed in the new LED driver Fifty-six smaller pin, 5 mm × 9 Hao Mi quad flat no lead (QFN) package.

Figure 1 from the 45 volt input-driven one hundred and sixty sixteen 20 mm An Baiguang LED channel LED driver in Figure 1 from the 45 volt input-driven one hundred and sixty Sixteen of 20 cents An Baiguang LED channel LED driver New LED drive

2MHz switching frequency, with a peak efficiency of 92% (Figure 2), which do not need an external heat sink. New LED drive 2MHz switching frequency, with a peak efficiency of 92% (Figure 2), which do not need an external heat sink. In addition, the significant reduction 2MHz switching frequency printed circuit board (PCB) size required for multiple inductor, thus allowing the TV to use very thin shell. In addition, the significant reduction 2MHz switching frequency printed circuit board (PCB) size required for multiple inductor, thus allowing the TV to use very thin shell. This is a key factor, because most consumers want to install to the living room HDTV wall, so for aesthetic reasons, the need for light weight and low profile design. This is a key factor, because most consumers want to install to the living room HDTV wall, so for aesthetic reasons, the need for light weight and low profile design.

shown in Figure 1 Figure 2 hundred and sixty LED drive efficiency is higher than 92% as shown in Figure 2, Figure 1, one hundred and sixty LED driver efficiency higher than 92%

New PWM LED dimming drive capacity of up to 5,000:1. New LED drive capability of up to 5,000:1 PWM dimming. Figure 3 shows the PWM dimming waveform 5,000:1 and a very square LED current waveform. Figure 3 shows the PWM dimming waveform 5,000:1 and a very square LED current waveform. Even in only 2 microsecond conduction time, a 20 mA LED current and the 100Hz PWM signal on and off simultaneously. Even in only 2 microsecond conduction time, a 20 mA LED current and the 100Hz PWM signal on and off simultaneously. Higher PWM dimming ratio can be used to achieve a lower PWM frequency, but the 100Hz to ensure there is no visible flicker. Higher PWM dimming ratio can be used to achieve a lower PWM frequency, but the 100Hz to ensure there is no visible flicker.

Figure 3 Figure 1 circuit 5,000:1 optical modulation pulse width modulation waveform in Figure 3 Figure 1 circuit 5,000:1 optical modulation pulse width modulation waveform < / P>

Complete all sixteen channels LED brightness through a single external resistor to set the per-channel programming with the same LED current (set at 10 to 50 mm between security), channel to channel LED current accuracy within 8%. All sixteen channels of full LED brightness via a single external resistor to set the per-channel programming with the same LED current (set at between 10 to 50 mA), channel to channel LED current accuracy of 8% inside. True Color PWM dimming duty cycle with reduced dimming to provide accurate, while the emission of light without any color shift, fixed frequency, current mode control circuit in a wide input and output voltage and current to provide stable operation. True Color PWM dimming duty cycle with reduced dimming to provide accurate, while the emission of light without any color shift, fixed frequency, current mode control circuit in a wide input and output voltage and current to provide stable operation. Through the internal sense resistor for LED current control for each channel, and internal switches for each channel LED driver and control circuitry to provide an excellent source of constant current regulation performance. Through the internal sense resistor for LED current control for each channel, and internal switches for each channel LED driver and control circuitry to provide an excellent source of constant current regulation performance. 100 mA internal power switch and Fifty-six of the exposed pin QFN package thermal pad to provide sufficient power and heat management to deal with the sixteen-channel 50 mA power consumption and heat. 100 mA internal power switch and Fifty-six of the exposed pin QFN package thermal pad to provide sufficient power and heat management to deal with the sixteen-channel 50 mA power consumption and heat.

LED backlit HDTV has clearly become the mainstream choice, but the system designer still has to meet specific performance requirements of the design LED driver. HDTV LED backlight has clearly become the mainstream choice, but the system designer still has to meet specific performance requirements of the design LED driver. Therefore, LED drivers should be able to meet the input voltage range, output voltage and current requirements into architecture for different types of LED configuration provides sufficient current and voltage. Therefore, LED drivers should be able to meet the input voltage range, output voltage and current requirements into architecture for different types of LED configuration provides sufficient current and voltage. Therefore, LED drivers should have the following characteristics, such as the wide input voltage range, wide output voltage range, high-efficiency conversion, strictly regulate LED current matching, low noise constant frequency operation, independent current and dimming control, wide dimming ratio and with very few external components small footprint solution for sperm to meet the needs of designers. Therefore, LED drivers should have the following characteristics, such as the wide input voltage range, wide output voltage range, high-efficiency conversion, strictly regulate LED current matching, low noise and constant frequency operation, independent current and dimming control, wide dimming ratio and with minimal external components small footprint solution for sperm to meet the needs of designers.