LED screen current drive design principle
Tags: led, screen
Published: 2023-09-08 03:28:35

As the largest outdoor application product, [LED electronic display ](https://sostron.com/product?category=2)is an indispensable product for large-scale entertainment, sports events, large square screens and other places. From single and double-color simple text display to today's high-definition full color, display technology has always been Progress, 80% of the world's LED electronic displays are produced in China. The quality assurance of the display screen is inseparable from the stable current design. 

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/ful532jro92j3wj983xf.png)
The design principle of LED (light emitting diode) screen current drive involves the basic working principle of LED and how to control the current of LED to realize brightness adjustment. LED screens typically contain thousands of LEDs, so their current must be efficiently controlled to achieve the desired brightness and color.

The following are the basic principles of LED screen current drive design:

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/rdoriivwd34ni0m1fak5.png)
LED basic principle:

LEDs are semiconductor devices that emit light when electricity passes through them. The color of the emission is determined by the material and doping.
The current-brightness relationship of LEDs is usually approximately linear, but it should be noted that there is a certain nonlinear relationship between the brightness of LEDs and the current. This means that when changing the brightness, the current has to be adjusted somehow. [Here's what to know about nit brightness. ](https://www.sostron.com/service/faq/4780)

Constant current drive:

Most LED screens are driven with a constant current. This means that the current to the LED is kept constant, while the brightness is achieved by controlling the on and off times of the LED.
Commonly used current values may be 20mA, 30mA, etc. The driver circuit keeps the current constant but changes the brightness by changing the LED on and off.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/8oapsmmhnxx78d86zno7.png)
PWM dimming:

PWM (Pulse Width Modulation) is one of the common LED brightness adjustment methods. It controls the brightness by switching the current of the LED at a high frequency.
In PWM, the LED flashes at a very fast speed (usually a few hundred hertz to a few thousand hertz), but it is imperceptible to the human eye. By adjusting the time the LED is on (duty cycle), the brightness can be controlled.

Current source drive:

In order to realize constant current driving, a current source circuit is required. This can be a linear regulator or switching regulator based design.
A linear regulator steps the voltage down to match the voltage requirements of the LED, and then controls the current through a current limiter. This method is less efficient because it wastes the voltage difference.
Switching regulators (such as Buck, Boost, or Buck-Boost) are more efficient and can adjust the voltage between the input and output to provide a stable current. This saves energy.

Temperature compensation:

Temperature has an impact on the performance of LEDs, so some LED screen current drive designs include temperature compensation loops to ensure that the brightness of the LED remains consistent at different temperatures.

![Image description](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/748zzb2crmoywx6rjw2c.png)
Color Control:

For color LED screens, RGB (red, green, blue) LED combinations are usually used. Each color channel requires separate current control. Mixing the brightness of different colors can achieve the desired color effect.
LED screen current drive design needs to comprehensively consider multiple factors such as LED characteristics, power supply design, PWM control, temperature compensation and color control. It is usually done by specialized electronic engineers and hardware designers to ensure that the screen works properly under different brightness and color conditions.

Thank you for watching. I hope we can solve your problems. Sostron is a professional LED display manufacturer. We provide all kinds of displays, display leasing and display solutions around the world. If you want to know: [LED display safety brightness parameter setting method and protection.](https://dev.to/sostrondylan/led-display-safety-brightness-parameter-setting-method-and-protection-264j) Please click read.

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