With the wider and wider demand for LEDs in our society, we are in contact with LEDs all the time in our lives.
We want to know more about LED-related information, it has to mention one of its core technologies – common cathode technology. The common cathode LED for the development of LED has a very important significance. In the end, what is the common cathode LED? We went through this article together to understand it.
What is a common cathode LED?
Common cathode is a semiconductor device in a configuration. The current common cathode LED in the use of LED displays is very common; the common cathode LED is the cathode of all LEDs that are connected to the common ground or common negative.
This circuit form can improve the stability and uniformity of the LED display screen to a certain extent, as well as the precise control of color. The current common cathode LED is very popular in the LED display industry.
The working principle of a common cathode LED
Common cathode LED by directly connecting the cathode of multiple LEDs to a common ground, while the anode of each LED is connected separately, this connection can simplify part of the circuit, reduce some of the resistance and consumption of electricity.
Therefore, common cathode LED is also known as energy-saving LEDs. The current reaches the negative pole of the driver IC from the LED chip, and this common cathode power supply can reduce the voltage drop and current loss, which can achieve the effect of energy saving to a certain extent.
In addition, each LED lamp bead contains red, green and blue three colors of lamp beads, these three colors of lamp beads need LED chip rated power is different, ordinary power supply method is difficult to distinguish between these three colors of LED chips, but the common cathode LED can be in the same current to provide them with different voltages, so that the three colors of LED chips are in the rated power to work.
Advantages of a common cathode LED display
Improved Energy Efficiency
Due to the power supply principle of the common cathode LED, it simplifies part of the circuit in the process of power supply and reduces the current loss; and the voltage control of the common cathode LED display is extremely precise for the LED IC chips of the three RGB colors, which allows the power supply to be used more efficiently and consume less power.
From these two aspects, a common cathode LED display can reduce energy loss and improve energy efficiency.
Vivid color and contrast
Each RGB color LED lamp bead can be independently controlled, which also means that the common cathode LED display can control individual colors more accurately, thus reducing color mixing and allowing colors to be accurately reproduced, and this accurate control also ensures the uniformity of the entire LED screen display, which solves the problem that the traditional monitor screen display may not be uniform.
Common cathode LED technology can also enhance the contrast and color vibrancy of the LED display, so that the LED display screen is of higher quality, leaving a clearer and deeper impression on the audience.
Extended service life
We mentioned earlier that the common cathode LED technology reduces the energy consumption of the display, the same common cathode LED also reduces the heat energy, the less heat energy is released in the process of work, the higher the stability of the LED screen, the lower the probability of damage to the LEDs, and the longer the service life of the LED screen.
Pixel-level control
Unlike traditional LED displays, where a group of LEDs shares a common connection, common cathode LED displays can realize individual pixel control, allowing each pixel on the LED display to be controlled individually for finer adjustment.
Limitations of the common cathode LED
High-performance requirements of the driver chip
The driver chip has to accomplish precise voltage and current control, which requires high performance, therefore, the cost of the common cathode LED chip will increase a lot compared with traditional LED.
Difficult circuit design
Each LED lamp bead has to be controlled independently, which requires high circuit design, and the difficulty of manufacturing cathode LED circuits has increased a lot.
The main differences between common cathode LEDs and common anode LEDs
Direction of current flow
Common anode LED: the direction of current flow from the PCB to the diode, and RGB three-color beads are the same power supply, the forward voltage drop increases.
Common cathode LED: the current flows from the red, green, and blue LEDs to the negative side of the IC. The voltage and current of the three-color LEDs are distributed separately, the forward voltage drop decreases, and the internal resistance is smaller.
Supply Voltage
Common anode LED: usually RGB three-color LEDs use the same voltage, which is above 3.8V, common anode LED power consumption is greater than common cathode.
Common cathode LED: Common Cathode LED gives different voltages to RGB three-color LEDs, which reduces the power consumption by lowering the voltage of the red LED. For example, the green and blue LEDs in common cathode LEDs are 3.8V, and the red is 2.8V.
Energy efficiency and cooling effect
Common anode LED: The voltage of common anode LED is higher than common cathode LED under the same overall conditions, so the heat generation of common anode LED is slightly higher than common cathode LED, and the energy efficiency is slightly lower than common cathode LED.
Common cathode LED: Common Cathode LED is able to precisely control 3-color LEDs, by reducing the voltage of red LEDs, reducing energy consumption and heat release, so Common Cathode LED has higher energy efficiency.
Supply Chain
Common anode LED: Common Anode LED technology is more mature, so the supply chain of related electronic components is also more mature and stable.
Common cathode LED: Common cathode LED is relatively more complex regarding the layout of components on the PCB, and these related supply chains are still in the early stages.
Application of a common cathode LED in an LED display screen
Advertising Media
Common cathode LEDs enable LED displays to have better color vibrancy and contrast, so they are very popular in the advertising and media industry.
It is often used in advertising and promotional displays, broadcasting advertising videos in various streets and alleys, the common cathode LED display can present high-definition and colorful advertising images, leaving a deep impression on the audience.
Sports Events
In sports competitions, we often need to play back the key clips of the game as well as real-time display of scores, in sports-related events, LED screens are also indispensable to the existence. The common cathode LED display is able to play back these images in high definition and smoothly, giving the audience an extremely shocking viewing experience, so it is also quite popular in the sports industry.
Stage performance
Stage background embellishment, stage screen broadcast can be achieved using a common cathode LED display, and its high brightness and accurate color control can make the performance screen very pleasing to the eye, so that the audience gets a richer and more colorful visual effect.
Comparison of the common cathode LED display and other display technologies
Currently on the market more common display technology, in addition to the common cathode LED display, there are LCD, OLED, we can do a simple comparison.
LCD
LCD is through the liquid crystal molecules of the twisted transformation to screen the light, screened light reaches the pixel to achieve imaging, LCD does not have self-luminous properties, need to have LED as a backlight to support the LCD luminous, so it’s not high brightness, and high energy consumption, overall, LCD color vividness is not as good as the OLED and the common cathode LED display.
OLED
OLED can emit light independently, and the picture is high-definition, colorful, and can meet the needs of indoor viewing. The brightness of OLED is lower than that of LCD and common cathode LED displays, not suitable for outdoor use. OLED has the risk of a burned screen, when using it, you need to pay attention to more.
Common Cathode LED Display
Among the three display technologies, the common cathode LED display has the highest brightness threshold, and can be clearly viewed even when exposed to strong light outdoors, and the common cathode LED display has strong color expression, uniform and stable picture, regardless of whether it is outdoor or indoor, even if it is a demanding high-end occasion can also meet the display needs.
Conclusion
The common cathode LED not only makes the LED display screen quality effectively improved, it also reduces the power consumption, for the development of LED display provides a better direction, and, in the case of science and technology continues to grow, the common cathode LED technology will become more and more mature, so that the development of common cathode LED display more and more good.
