[Source: Gaogong LED's "LED Good Products" January issue (total issue 61) Wen | Gan Qin] Currently in the field of LED general lighting, there are many LED products still using switch mode power supply. However, in recent years, with the continuous improvement of the linear drive, the drive volume has become smaller and compatible with TRIAC dimming, which can extend the life of the bulb and reduce the cost, and is expected to become a new direction of LED driving in the future.
“The LED lighting driver has evolved from the original bulky and bulky isolation type to the current non-isolated type, which is smaller and more efficient.” Li Zhaohua said that as the size of the bulb on the market is getting smaller and smaller, the driver IC will also gradually evolve from the current mainstream non-isolated type to the future linear drive and integration.
In order to solve the problem that LED lamps have serious light decay and reduce LED service life due to the high internal temperature of LED lamps, Mingwei Electronics has introduced linear constant current driving chips such as SM2083 and SM2086. "These chips integrate temperature compensation. When the internal junction temperature of the chip exceeds a certain temperature (such as 110?C), the output current will be automatically reduced to reduce the internal temperature of the lamp."
In addition, because the linear drive is free of transformers, inductors and other components, it is easy to seal with the LED lamp bead. In addition, the linear drive does not involve the transient process of "switching power supply", and there is no EMC interference problem. Therefore, the linear drive is also called "green". Constant current power supply."
In addition to Ming Microelectronics, Dianbu Integrated has continued to focus on the development of linear constant current drive ICs since last year. Its general manager Chen Hengyu said that the company's self-developed high-order segmented linear constant current drive IC-SDS3108 has been acquired. A number of invention patents.
Chen Hengyu introduced, "This high-order segmentation technology uses N-type switches and P-type switches to cooperate with each other. The power efficiency can reach more than 93%, and the heat dissipation power is reduced by 60% compared with the four-stage linear constant current chip. The technical application of 'dynamic configuration' and 'active filling valley'.
Chen Hengyou believes that compared with switching power supply, linear constant current drive has the advantages of low cost, convenient installation, long lamp life and simple intelligent dimming. Therefore, linear drive will become an important trend in the development of LED industry.
