Knowledge analysis of LED common cathode technology




After years of development, the conventional common anode LED display has formed a stable industrial chain, which has promoted the popularization of LED display. However, it also has the shortcomings of excessively high screen body temperature and excessive power consumption. After the emergence of the common cathode LED display power supply technology, it has attracted great attention in the LED display market. This power supply method can achieve the highest energy saving of 75%, so what is the common cathode LED display power supply technology? What are the advantages of this technology?


1. What is a common cathode LED display?

 

"Common cathode" refers to the common cathode power supply method. In fact, it is an energy-saving technology for the LED display. B (red, green, blue) is supplied separately, and the current and voltage are accurately distributed to the R, G, and B lamp beads, because the R, G, B (red, green, blue) lamp beads need the best working voltage and The currents are not the same, so that the current passes through the lamp beads and then to the negative electrode of the IC, the forward voltage drop will be reduced, and the internal resistance of the conduction will be reduced.

 

2.What is the difference between common cathode/common anode LED display?


. Different power supply methods:

The common cathode power supply mode is that the current passes through the lamp beads first, and then to the negative electrode of the IC, so that the forward voltage drop is reduced, and the internal resistance of the conduction is also reduced.

LED diode  

The common anode means that the current flows from the PCB board to the lamp beads, and supplies power to R, G, and B (red, green, and blue) uniformly, which causes the forward voltage drop of the circuit to become larger.

. The power supply voltage is different:

Common cathode, it will separately provide current and voltage to R, G, B (red, green, blue). The red, green, and blue lamp beads have different voltage requirements. The voltage of the red lamp bead is about 2.8V, and the voltage of the blue and green lamp beads is about 3.8V. This power supply can achieve accurate power supply and low power consumption. , The heat generated by the LED display during work is also much lower.

 

The common sun is to give a voltage higher than 3.8V (such as 5V) to R, G, and B (red, green, and blue) to provide a unified power supply. At this time, the red, green, and blue voltages are all unified 5V. However, the optimal working voltage of the red, green, and blue lamp beads is much lower than 5V. According to the power formula P=UI, when the current is constant, the higher the voltage, the higher the power, which is The greater the power consumption, at the same time, the LED display will also produce more heat during work.


3.Why the common cathode LED display has lower heat?

 

The special common cathode power supply mode of the cold screen makes the LED display less heat and low temperature rise during the working process. Under normal circumstances, the temperature of the cold screen is about 20°C lower than the conventional outdoor LED display of the same model in the white balance state and when playing video. For products with the same specifications and with the same brightness, the screen temperature of the common cathode LED display is more than 20 degrees lower than that of the conventional common anode LED display product, and the power consumption is 50% lower than that of the conventional common anode LED display product. above.

 

The high temperature of the LED display screen and the excessive power consumption have always been the key factors affecting the service life of LED display products, and the "common cathode LED display" can solve these two problems well.

 

4. What are the advantages of the common cathode LED display?

 

. Precise power supply is really energy-saving:

Common cathode products adopt precise power supply control technology, based on the different photoelectric characteristics of LED red, green and blue, with smart IC display and control system and independent private mode, which accurately allocates different voltages for LEDs and drive circuits to make the product power consumption relatively Similar products on the market save about 40% of electricity!

 

. Real energy saving brings true colors:

The common cathode LED driving method can accurately control the voltage, and while reducing power consumption, it also reduces the amount of heat. The LED has no wavelength drift under continuous operation, and the true color is displayed stably!

 

. Real energy saving brings long life:

Energy consumption is reduced, thereby greatly reducing the temperature rise of the system, effectively reducing the probability of LED damage, improving the stability and reliability of the entire display system, and greatly extending the life of the system.

 

5. What is the development trend of common cathode technology?

 

Supporting the common cathode LED display technology, such as LED, power supply, driver IC, etc., is not as mature as the common anode LED industry chain. In addition, the current series of common cathode IC is not complete, and the overall amount is not large, and the common anode still occupies 80% Market.

 

The current slow progress of common cathode technology is mainly due to high production costs. Based on the original supply chain collaboration, common cathode requires customized cooperation at all ends of the industrial chain such as chips, packaging, and PCB, and the cost is relatively high.

 

In this era of high demand for energy conservation, the emergence of the common cathode transparent LED display has become the support point of this industry's pursuit. However, there is still a long way to go to achieve comprehensive promotion and application in a larger sense, which requires the joint efforts of the entire industry. The common cathode LED display, which is the development trend of energy saving, involves the use of electricity and operating costs. Therefore, energy saving is related to the interests of LED display operators and also related to the use of national energy.

 

Judging from the current situation, the common cathode LED energy-saving display screen will not increase the cost too much than the conventional display screen, and it will save costs in the later use, which is highly praised by the market.