LED electronic display driver chip worrying!

After since LED electronic display is known as the city fourth screen, it seems that the global economy developed city by LED electronic display enveloped overnight, then LED electronic display so welcome to global stardom overnight! He is said to have the world's third most advanced technology! So in the process of using the LED display or LED display of the ability to drive what problems are not solved?

LED driver chip can be divided into general and special chip chip. General purpose chips are generally used in LED display of low-end products, such as indoor single, two-color screen, etc.. The most commonly used universal chip is 74HC595, with 8 bit latch, serial shift register and the output function of the three state. Maximum output current of 35 mA per channel (not constant current). General IC manufacturers can produce such chips.

LED is due to current characteristics of the device, which is based on saturation conduction, its brightness varies with the size of the current, not with the change of voltage change. Therefore, one of the biggest features of the dedicated core is to provide constant current source. Constant current source can ensure the stability of the LED drive, eliminating the flicker phenomenon of LED. The following will focus on LED display driver chip.

There problem

1 power consumption and heating problem

Due to large output current, power consumption and heat LED display chip is always the first factor in the development of block driver chip. This problem will become more prominent in the future of the handheld LED display driver. With the progress of the LED device manufacturing process and the reduction of drive current, the problem will be solved gradually.

2 application cost

A mainstream steady state current 16 bit LED display driver LED chip can drive the 16 road. A resolution of 1024 x 768 LED display on the need to use multiple chip driver in order to achieve the desired effect, so that the material cost is relatively high. If the use of the driver chip itself scanning mode, then a mainstream driver chip can drive multiple LED devices, will reduce the cost of many applications.

3 Summary

From several LED driver chip manufacturer, product structure, the current mainstream chip is mainly divided into 3 grades. The first level is a gray chip, this chip has a built-in PWM function, can be generated according to the input data gray, more likely to form a deep gray, high-quality display screen. Second grade is the output open circuit detection (LOD), overheat protection (TSD), brightness adjustment function of the chip, the chip with additional functionality and more suitable for special occasions, such as for the variable information board, is required to detect LED chip with fault energy. The third is the constant current source chip without any additional functions, such as LED chip only provides a constant current source, to ensure the good quality of the display screen.