LED is a semiconductor device similar to ordinary diode, the LED V-I curve.  
 
Within a certain range, the brightness of the LED is basically proportional to the current, but when the current exceeds the rated value, as the current increases, the brightness is almost no longer strengthened. After exceeding the extreme current, the luminous pipe may burn out.  
 
LEDs can be driven by DC or AC drive. Most of the PWM (pulse modulation) driver can be used in LCD color TVs.  
 
The CCFL backlight driver belongs to the high voltage driver of AC, its initial lighting voltage is as high as 1000V, and the stable working voltage is also about 700V; LED is a semiconductor device. When the positive voltage is applied, the PN is guided, the LED devices are glowing, different colors (single) The positive voltage (VF) of the LED is as follows: red LED is 2V, green LED is 3.5V, and blue/white LED is 3.5-4V. If the V-I curve voltage of the positive LED on the LED increases, the current will rise sharply, and the brightness will rise until it is burned. It can be seen that LED is a current -type device, which is proportional to the current and brightness, which will cause the device to burn. Therefore, the brightness of the white light LED can be controlled by the current of the tube, and the brightness is proportional to the current. Generally speaking, the driver current of ordinary LEDs is less than 50mA, the driver current of large current LED is 50-150mA, and the driver current of high-power LED can reach 150-1000mA.