NXP RF Plasma Lighting Solution

Key Features/Advantages:

* High brightness, excellent color reproduction

* More compact than LED light sources with the same lumens

* Dimming - further reduces power consumption when maximum brightness is not required

* Reduce maintenance costs by up to 66% compared to conventional street lighting solutions

NXP’s deep understanding of RF technology has resulted in some of the most rugged devices in the industry – and we’ve incorporated that knowledge into our RF lighting transistors. The ultra-high efficiency of our LDMOS transistors also gives RF lighting an exceptional lumen/watt ratio that dwarfs conventional light sources.

Radio Frequency Plasma Lighting Technology

Recent advances in RF power technology—such as lower $/W RF power levels and significantly increased power density of single transistor devices to 1000 W—have led to a breakthrough light source technology: RF plasma lighting. Basically, the technology uses a small electrodeless quartz bulb containing an argon gas and metal halide mixture. The bulb is driven by directed RF radiation, which causes the gas mixture to glow, creating and driving a bright plasma whose color can be adjusted by the composition of the plasma components.

Ultra-long life of RF plasma lighting solutions

Unlike standard high-intensity discharge lamps, this technology produces light without any electrodes in the bulb. No electrodes means a very long operating life, as there is no contamination and cable corrosion that can reduce efficiency and eventually cause lamp failure. RF light sources have a lifespan of up to 50,000 hours (with a 50% reduction in light output), compared to 20,000 hours for typical high-intensity discharge lamps. Another advantage of plasma lamps is their efficiency: 1 W of RF power can be converted into 140 lm of light.

RF Plasma Lighting vs. Competitors

Plasma light sources eclipse most of their competitors. The most important thing is the high brightness per bulb: much brighter than LEDs, for example. LED luminaires for street lighting are much larger than plasma light sources. Due to the high brightness per bulb, plasma light sources have recently started to enter the market for applications that require more than 5000 lm per luminaire, such as street lighting and stage lighting.

The significance of radio frequency

RF driven plasma sources are a good example of many new applications in the ISM space that can be driven by RF energy. There are established technologies that use RF to drive gas discharges in laser cavities. These and most ISM applications present highly mismatched RF loads. When the gas discharges, the gas holes act as open circuits when turned on - so all the RF power "injected" is reflected into the amplifier's final stage and needs to be dissipated by the transistor. After the discharge, the load impedance will eventually return to "match" and the transistor will see a normal load. Obviously, this type of mismatched circuit will occur whenever a plasma is turned on, so the final stage transistor must be rugged enough to withstand these conditions. NXP provides exactly this solution.