LCDs (liquid crystal displays) are electronically controlled light valves. LCD TVs (liquid crystal display televisions) use a white “backlight,” typically cold-cathode fluorescent lamps (CCFLs), to illuminate the color screen. Other technologies, such as light-emitting diodes (LEDs), have been considered, but high cost has limited their adoption.

This article describes the design challenges of driving and controlling multiple CCFLs for backlighting large LCD panels like those in LCD TVs.