From the new look at the 2013 LED lighting program four trends

2012 is the past, this year for the LED industry is mixed, although many countries including Chinese, has banned the sale of incandescent lamp, LED lamp, but sales are not scheduled to burst, but there was a chain, many lighting manufacturers don't collapse, there are also manufacturers with earned pours, overall, this year the LED market is a normal adjustment of the year for 2013, LED lighting market, with 40 watts (W) to replace the incandescent lamp bulb LED minimum retail price has reached 10 U. s.dollars the sweet spot of industry have been optimistic expectations for the overall LED lighting market next year to warm, so now the industry to do is good technical reserves and scheme selection for the market, at the outbreak of commitment. Here, combined with Power Integrations and other mainstream LED vendors to release the latest new talk about the four trends in 2013 LED lighting program.

Trend 1: dimming technology upgrades, is expected to become a bright spot lighting

In LED lighting applications, dimming technology faces very big challenge, because the current LED lighting dimmer and driving mode, most of the existing voltage dimming, so in terms of compatibility challenges is quite large, but this is a weapon identification scheme, in the past LED dimming in the scheme, the common problems are dimming range small, light suddenly become bright, light low flicker and so on, seriously affect the user experience, however, with the special program PI company launched, LED dimming is expected to solve the problem, the LYTSwitch IC PI released the latest point of view, already can realize adjustment optical performance can be very good, can easily reach NEMA SSL6 standard angle even in lower conduction, the driver started very quickly, usually less than 500 milliseconds, even in the light output on the 10% when the start Speed is also very fast, the actual program, the use of LYTSwitch IC designed to be able to turn off the light bulb with almost the same angle, which virtually eliminates the sudden brightening phenomenon. In addition, the dead zone in the SCR dimming is also eliminated, because the LYTSwitch controller ensures that the dimmer is switched on immediately when the dimmer is working. In this regard, PI patented circuit technology, from the dimming curve, the PI program is indeed obvious advantages.

Figure 1 dimming curve of PILYTSwitch controller

Another challenge is dimming technology compatibility issues, there is still no solution can do 100% compatible dimmer, so it can do more than 90% has been very good, now claims that can do this ratio is Power Integrations, it seems, PI really have done a lot of work in terms of dimming. With the gradual popularization of LED lamps, dimming technology upgrades can bring more and better experience for users, will become a new selling point, the choice of the program can pay attention to this feature. In support of dimming mode, manufacturers generally support SCR dimming and PWM dimming.

Trend two: single level circuit architecture gradually occupy the mainstream

In the previous scheme, in order to obtain the dimming characteristics better, many solution providers using two architecture, namely "PFC (power factor correction) + isolation DC/DC converter" architecture, this design can effectively reduce the power ripple, because designers think that the single-stage PFC circuit ripple is too large, resulting in fear the life of LED, the luminous efficiency and color temperature, therefore, using double circuit more, and now, with the launch of a single-stage high frequency switching scheme, single stage circuit advantage is very obvious, because in terms of efficiency, the double level circuit to documentary level confrontation, at present several vendors can be single level scheme do more than 92% efficiency, double circuit, usually only about 85% efficiency.

Another advantage of a single circuit is simple, can be seen from the figure, PI program can achieve 92% efficiency! Therefore, the future use of a single circuit program will occupy the mainstream. This is also the view of some industry experts.

Trend three: integrated PFC, MOSFET standard

The previous scheme, especially for low power lighting solutions, many manufacturers did not consider the PFC circuit, because on the one hand, is not mandatory, on the other hand, will increase the project cost, but now in the low power driving scheme of integrated PFC has become a standard, this is the first big trend with energy saving and emission reduction, is also China government in the bidding project first explicitly put forward such requirements, therefore, chip manufacturers have to follow up.

For example, LYTSwitch IC PI PFC and constant current (CC) integrated into a single switch circuit, which can be efficiency in typical applications increased to more than 90%, power factor greater than 0.95, and easily meet the EN61000-3-2C of total harmonic distortion (THD) requirements. The optimized design of THD can be less than 10%. The following are three typical applications of circuit efficiency.

Figure 2 efficiency of three typical applications

[1] [2] next page