With the continuous development of technology and the continuous improvement of LED display technology, LED display products are gradually moving towards high-end. LED displays are controlled by computers, and intelligent full-color LED displays that integrate light and electricity have been widely applied in various fields.
Its pixel points use LED light-emitting diodes, which are arranged in a lattice manner to form an LED array, thereby forming an LED screen. By using different LED display screen driving methods, images with different effects can be obtained. Therefore, the quality of LED driver chips plays an important role in the display quality of LED displays. LED driver chips can be divided into general-purpose chips and specialized chips. Universal chips are generally used in low-end LED display products, such as indoor single and dual color screens. At present, the main manufacturers of LED display screen specific driver chips include TOSHIBA, TI, Sony, MBI, SITI, and others. In the domestic LED display screen industry, these chips have applications.
Due to the fact that LED is a current characteristic device, its brightness changes with the magnitude of the current under the premise of saturated conduction, and does not change with the voltage at both ends. The biggest feature of dedicated chips is to provide a constant current source output, ensuring stable LED driving and eliminating LED flicker. It has the characteristics of high output current and constant current, suitable for occasions that require high current and high image quality, such as outdoor full color screens, indoor full color screens, etc. The driver of LED display screens is generally a multi-channel constant current source (currently mostly 16 channels) combined with grayscale control and other functions.
The IC does not integrate power modules such as DC/DC, but in backlight and lighting drivers, the number of channels will be reduced, and the DC/DC conversion module is usually part of the IC. LED display screens place great emphasis on the refresh rate and image representation ability, with high matching, refresh rate, and resolution becoming important indicators for judging the performance of an LED display screen. This requires high consistency of current between IC channels driven by LED display screens, high-speed communication interface speed, and constant current response speed. The display driven technology focuses on LED grayscale linearity and fast output response.
The backlight factory adopts a multi parallel multi series architecture, which requires an operating voltage of up to 50V-60V. This will improve the process technology required to drive the IC. After the high voltage is connected in series, the difference in VF of each LED needs to be considered, which will have a significant impact on the overall power efficiency and Constant Current control.
