2010 is an important year for the development of large-size LED backlights. The advantages of LED backlights with ultra-thin, energy-saving and environmental protection, and high color quality have become a powerful driving force for the development of backlights. According to the forecast data of research institutions, in 2010, the global LED LCD TV sales will reach 32 million units, accounting for about 19% of all LCD TVs; in 2011, the use of LED backlight large-size panel shipment ratio will reach 56%, the traditional backlight panel Shipments will fall to 44%; by 2015, LED panel shipment penetration will reach 78%. In the Chinese flat panel market, LED will surpass CCFL ordinary LCD TVs in the past two years.
Zheng Zhaoxiong, senior director of global sales and marketing for OnSemi's semiconductor power and portable products, said that traditional LCD TVs use cold cathode fluorescent lamps (CCFL) backlights, which typically convert PFC voltages through 24V (conventional power supplies) or without 24V conversion (LIPS). The power supply) is boosted to an AC high voltage of more than 1,000V or even 2,000V to drive a strip or U-shaped CCFL tube; while the LED-backlit LCD TV uses several LED strips, mainly in an edge-lit or backlit scheme. Backlight, so an important requirement of power management is to provide high energy efficiency. In addition, in the case of TV sets, LED backlight LCD TVs have an ultra-thin appearance as an important selling point, so their power management solutions must have low height to match slim. Design, but also to consider heat dissipation, reduce electromagnetic interference, different channel brightness matching, dimming and fault diagnosis and protection issues.
“As mentioned above, these conditions require semiconductor devices and solutions to provide energy efficiency, using smaller (especially low-profile) components for a slimmer design while taking into account improved heat dissipation, reduced electromagnetic interference, and high brightness matching. (to provide a consistent brightness backlight), dimming, diagnosis and protection, etc.. Zheng Zhaoxiong added.
At present, ON Semiconductor can provide both edge-lit and direct-lit LED backlight solutions. Taking the edge-lit solution as an example, ON Semiconductor offers a cost-effective multi-channel linear LED side-lighting solution that uses the NCP1397 primary-side controller and the 500V high-voltage MOSFET NDF05N50 in the half-bridge conversion stage, while using the 6-channel linear LED driver CAT4026. CAT4026's target energy efficiency is higher than 90%, typical energy efficiency is 94%, providing "±2% excellent current matching accuracy and 1% 400Hz PWM dimming range, and using external power bipolar junction transistor to provide heat dissipation, better Handle heat issues.
In addition to the linear side-lighting solutions based on the NCP1397, NDF05N50 and CAT4026, ON Semiconductor also offers direct-down step-down drive solutions based on the NCP1397, NDF05N50 and NCP1034. The NCP1034 drives a pair of external N-channel MOSFETs with a programmable switching frequency of up to 500kHz, providing the flexibility to adjust the operation of the integrated circuit (IC) to meet system level requirements. In addition, the internal 1.25V reference voltage allows precise regulation of the output voltage for low voltage applications. This device's protection against electrical faults, such as undervoltage lockout and hiccup current limiting, provides the required system level safety in the event of a fault. Advantages include driving energy efficient FETs and providing a fixed frequency for one or more devices.
It is worth mentioning that ON Semiconductor provides a complete solution for LED-backlit LCD TVs, including side-light or direct-lit backlighting, including power factor correction (PFC), standby switching power supplies, and related rectifiers, operational amplifiers, and MOSFETs. And discrete devices, etc., to provide customers with a one-stop solution.
Tony Armstrong, director of marketing for Power Products at Linear, believes that traditional LCDHDTVs use CCFL tubes as backlights, with the exception of the contrast ratios of only 450cd/m2 to 650cd/m2. It is also "not able to completely turn off the CCFL backlight or locally dim it." That is to say, the current generation of LCDHDTV is unable to obtain true "black", and the dynamic range of all colors is low.
In contrast, when using HBLED backlighting, an LED array capable of local dimming or shutdown with a backlit "LED cluster" (up to 1,600 LEDs for a 46-inch display) is provided. Almost an order of magnitude higher contrast ratio ("4,000 cd/m2" than the CCFL design. In addition, by adjusting the brightness of the backlighting LED group, more midtones can be reproduced, making the image more lifelike.
“Another benefit is the ability to turn off the LEDs completely at a local location, thus reducing motion blur. By completely turning off the LEDs between frames, the image blur caused by fast moving objects will actually be eliminated, therefore, The fast response rate of LEDs is critical," Tony said.
He once again emphasized the importance of driver ICs for the reliability and longevity of LED products. In addition to making the solution slimmer, compact, and flat, the driver ICs operate at high switching frequency. In an inductor-based DC/DC switching topology, these high switching frequencies reduce the values ​​of the inductor and output capacitors. Size and cost. In addition, in some cases, the driver IC can also achieve on-chip integration of Schottky diodes and boost diodes, thereby reducing the number of external components. This in turn reduces design complexity and reduces the size and cost of the solution.
Moving head beam light
Well and hight quality control
New design products
Customers design and Logo are welcomed
Quickily delivery
Competitive prices
Fit for gifts and premiums
sample can be available
OEM acceptable
Years of exporting experience as professional stage lighting manufacturer:
Senior R&D technical staff with 7 years experience in stage lighting industry;
Strict quality control in producing to maintain reliable quality;
Provide cost-effective products, wholesale price;
Professional sales team to provide perfect service.
Our company have 13 years experience of LED Display and Stage Lights , our company mainly produce Indoor Rental LED Display, Outdoor Rental LED Display, Transparent LED Display,Indoor Fixed Indoor LED Display, Outdoor Fixed LED Display, Poster LED Display , Dance LED Display ... In additional, we also produce stage lights, such as beam lights Series, moving head lights Series, LED Par Light Series and son on...
Moving Head Light Series,Beam Moving Heads Light,Beam Moving Light,Moving Head Light Beam
Guangzhou Chengwen Photoelectric Technology co.,ltd , https://www.cwstagelight.com