Should You Be Converting Your LCD Backlighting from CCFL to LED?

ERG has the answers:


CCFL or LED: which is the Better Backlight for my panels?
That depends.  Both CCFLs and LEDs are good technical solutions for the most common LCD backlighting requirements.  For today and for some time to come, CCFLs are significantly more cost-effective for all but the smaller displays (cell phones, MP3 players, etc.). Therefore, CCFLs will continue to be used to backlight the majority of medium to large industrial displays. However, LEDs are on a declining price track, and it is expected by many experts that LED backlighting costs will eventually reach parity with CCFLs, but not for some time yet. When that does occur, LEDs can be expected to assume a dominant position in backlighting.

There are many applications today where the features of LEDs may justify their higher up-front cost.  LEDs can provide higher brightness than CCFLs. When properly integrated into a system, LED backlights have a longer lifetime than CCFL backlights.  LEDs can be operated efficiently over a wider temperature range, particularly at the low end, than CCFLs.  In applications where the high voltage required for CCFLs is an issue, such as explosive environments, the ability of LEDs to operate at low level DC voltages can be a distinct advantage. Other advantages of LEDs include increasingly higher light output per electrical power input, and the ability to optimize color gamut.  Finally, the wide range dimming capability of LEDs can be a valuable advantage in some applications.

However, for numerous LCD backlighting requirements that do not require the advantages of LEDs noted above, CCFLs still represent the best solution due to their significant cost advantage. For special requirements, the extra capabilities of LEDs must be weighed against their considerable extra cost in determining the optimum solution.





Am I safe staying with CCFL backlights? Are they going to go away?
Yes, you are safe staying with CCFL backlights. CCFLs have been around for many years and they aren’t going away any time soon. Although the total number of CCFLs used in the future may decline, the cost savings of using CCFLs will still prohibit a move in the direction of LEDs for many applications.

The available backlights in OEM LCDs are determined by the LCD manufacturer, unless the LCD is being modified. There are certain market segments that have and will be moving from CCFL to LED backlights because of certain factors, the first being brightness, the second being power savings.  Most LCD manufacturers will offer LED backlights as an option in targeted markets.  





Do I need to spend the extra dollars on an LED BLU?
If the application supports it, yes. The advantages of LEDs over CCFLs in certain operating environments are best measured by performance rather than price.





Will I still be able to get the CCFL inverters I need?
Yes. Endicott Research Group’s inverter designs never go end of life. The ERG inverter design process ensures that there will be worldwide product support for years to come.





Where should LED be my backlight of choice?

  • Projects that will be operating in the extreme cold, operating at high altitude,  or in high bright applications such as ATMs, gas pumps, portable medical equipment, marine navigation displays, aircraft cockpit displays, and automotive passenger entertainment displays.
  • Where greater dimming ratios are required. LED backlights enable this due to quicker LED turn-on time, as compared with CCFL backlights.
  • Where “going green” is an objective. Designs that use LEDs do not contain mercury.
  • Power- sensitive designs -- OEM LCDs with LEDs typically use less power than their CCFL counterparts.  

driver rail


How do I best power LED BLUs?
It is best to power the LEDs with a regulated DC current source such as the Smart Force™ line of LED drivers. Smart Force LED drivers are designed specifically for OEM LED backlights or LED strings. Standard features of the Smart Force designs are wide input voltage range and industry leading wide range PWM dimming.