Diversified Solutions of LED Backlight
With the promotion of more and more new demand and green, energy saving trend, power and power management technology which can improve energy efficiency will be rapidly developed. Backlight is a typical application demand.
Though CCFL is still the main backlight of LCD TVs currently, the LED backlight has already been much concerned to be the strong competitor of CCFL.
Demand and challenges
High color saturation, environmental protection and endurance of LED make it widely used in LCD panel board with all sizes. It's now entering portable computers, LCD TVs market gradually. 3% LCD TVs adopted LED backlight in 2009, it will be 40%-50% in the next three or four years. Compared with CCFL, LED backlight is with more advantages. LED adopts low-voltage drive, it's safe and electricity saving, circuit design is simple. No mercury to cause harm to environment.
Also there are some challenges LED technology is facing ,like low luminous efficiency, high cost, high price. With the LCD backlight mainly transfers to LED technology, design engineers are facing new challenges of power management, heat management and color management.
Diversified backlight solutions of ONSemiconductor
Backlight solutions for LCD TVs
There are mainly two solutions for LED backlight LCD TVs. One is sidelight solution: it consists of backlight convertor and LED controller, supporting low height LED backlight LCD TV design, less than 8mm on circuit board and total height less than 12.5mm. It can optimize wide-range light adjustment, heat dissipation, breakdown protection,etc, solving the power design problem.
Another one is voltage deduction drive method based on NCP1397, NDF05N50 and NCP1034.This solution can prevent electrical failure. Its advantage is to provide fixed frequency and drive highly efficient FET.
Portable LED backlight solutions
Cellphone and digital camera: ONSemiconductor provides linearity, electric inductance and charge pump LED drive devices for cellphones and digital cameras.
These drive solutions are with high efficiency, can extend battery lifetime and reduce circuit panel area and height to realize ultra thin mode.