How to supply power for a common cathode LED display, what are the advantages and trends?

08/10/2021
What are the advantages of the power supply technology of ordinary cathode LED display

1. What is a common cathode LED display?

"Common cathode" refers to a common cathode power supply mode. In fact, this is an energy-saving technology for LED displays. Refers to the use of ordinary cathodes to supply power to the LED display. B (red, green, blue) separates the power supply, and accurately distributes the current and voltage of the R, G, and B lamp beads, because the R, G, B (red, green, blue) lamp beads need the best working voltage, and the current is different. Therefore, the current will first pass through the lamp beads and then reach the negative electrode of the IC, reducing the forward voltage drop and reducing the internal conduction resistance.

2. What is the difference between common cathode and common anode LED displays?

①. Different power supply methods:

The commonly used cathode power supply method is that the current passes through the lamp beads first, and then reaches the negative electrode of the integrated circuit, so that the forward voltage drop becomes smaller and the internal resistance of the conduction becomes smaller.

The common anode is the current flowing from the PCB board to the lamp beads, and evenly supplies power to R, G, B (red, green, and blue), so that the forward voltage drop of the circuit becomes larger.

②. The power supply voltage is different:

Common cathodes provide current and voltage for R, G, and B (red, green, and blue) respectively. 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 kind of power supply can realize accurate power supply and power supply. Due to the smaller loss, the heat generated by the LED display during operation is much lower.

The common cathode must give R, G, B (red, green, and blue) a unified power supply higher than 3.8V (such as 5V). At this time, the voltage obtained by red, green, and blue is uniform 5V, and red, green, The best operating voltage required by the three blue lamp beads is much lower than 5V. According to the power formula P=UI, under constant current conditions, the higher the voltage, the greater the power, that is, the greater the power consumption, and the LED display is working. More heat will be generated in the process.