With the diversification of lighting requirements, LED lighting has been widely developed in various use scenarios due to its stable and efficient characteristics, and the continuous updating and iteration of LED lighting driver chip technology and manufacturing process has become the key device for the continuous development of lighting products. According to the statistics of the LED Research Institute of Advanced Industry, Industry and Research (GGII), the output value of China's LED lighting market has increased from 301.7 billion yuan in 2016 to 526.9 billion yuan in 2020, with a compound annual growth rate of 14.95%, and the size of China's LED lighting market has reached 582.5 billion yuan in 2021.

Next, the LED lighting general chips and smart chips are described, and the technical status and market application pattern of these two major types of lighting driver chips are introduced.

Universal drive chip technology: integration, reliability and reduction of interference to power grid

At the early stage of the development of universal driver chip technology, it is generally only required to achieve constant lighting current and simple protection functions. With the development of lighting demand, the universal driver chip technology is no longer satisfied with the basic LED lighting demand, but gradually develops towards how to better improve the chip integration, system reliability, and reduce interference to the power grid.

The constant current accuracy and other indicators in the historical development have become the necessary standards for the qualification of universal driver chips, while the technical challenges faced by various manufacturers and the indicators to measure the progressiveness of chips point to the research direction of chip integration, reliability and reducing the interference to the power grid that requires more scientific and technological personnel and research and development efforts.

Intelligent driver chip technology: PWM/analog dimming, low power consumption and high compatibility

Intelligent lighting is the intelligence of lighting. It adjusts the brightness, color temperature and color of LED lights through the LED lighting driver chip interface, and integrates intelligent modules such as Wi-Fi and Bluetooth to realize the intelligent control of lighting equipment.

LED dimming mode

At present, there are many LED dimming methods on the market according to different technologies and different protocols. In summary, LED dimming methods can be divided into intelligent programmable, intelligent dimming technology controlled by MCU and mechanical dimming, silicon controlled dimming that cannot be controlled by MCU and manual switch dimming. All kinds of dimming methods are produced according to the needs in different periods, so their application objects and scope are also different.

SCR dimming is a kind of mechanical dimming, which uses SCR angle cutting technology for dimming. This dimming method can be traced back to the era of incandescent lamps. It is the earliest dimming method used by LED lamps. It has dominated the lighting industry for many years with its low-cost advantages. However, there are also some defects. Before the thyristor rectifier is turned on, the voltage increases sharply, which is easy to cause LC filter oscillation, thus causing audible noise and stroboscopic problems.

Manual switch dimming/color cutting uses the switch on the wall within the specified time to achieve the purpose of dimming/color cutting. This technology was first used in CFL energy-saving lamps, and then extended to LED lighting. The control chip simultaneously completes constant current drive and switch dimming control. The method is simple but can only be manually adjusted according to the preset brightness cycle.

Intelligent dimming technology

Unlike general lighting or ordinary dimming, intelligent dimming technology must integrate intelligent modules such as Wi-Fi, Bluetooth, infrared, radar, voice control, etc., and remotely adjust the brightness, color temperature, color, etc. of LED lights through mobile phone APP, Bluetooth, infrared remote control through LED lighting driver chip interface.

There are three main methods of intelligent dimming technology. One is PWM chopped dimming (Philips patent). This method is simple to realize and has good dimming depth, but it cannot solve the stroboscopic problem; The other is analog level dimming, which can realize stroboscopic dimming, but the dimming depth cannot be higher; The third is PWM to analog dimming, that is, through the circuit design technology of the chip, the external input PWM dimming signal is converted into analog dimming inside the chip, and the problems of stroboscopic and dimming depth are solved at the same time.

In addition to intelligent dimming technology, in view of the characteristics of intelligent products, downstream manufacturers also put forward higher and higher requirements on whether intelligent drive chips can ensure low power consumption and high compatibility of intelligent products.

According to the research report of Prospective Industry Research Institute and Guoyuan Securities, the output of LED lighting products in China will be about 12 billion and 13.2 billion in 2019 and 2020 respectively. Combined with the growth of LED lighting market scale, China's lighting product output will be about 14.5 billion in 2021.

In the field of dimming lighting, the total shipments of intelligent dimming products in the past three years were about 800 million, 1.3 billion and 1.9 billion, respectively. The switch dimming and silicon controlled dimming products basically shared the remaining share.

With the concept of smart city and whole-house intelligence being proposed, more intelligent lighting experience and application are attracting more and more attention. From the market distribution of LED lighting products, it can be seen that the real intelligent dimming products currently account for about 13% of the entire lighting market. The development prospect is broad and the intelligent driver chip belongs to a relatively emerging technology field. There is still a technical threshold that needs to be further overcome, and it needs the joint efforts of the majority of chip suppliers.