LED backlight
Due to the inherent deficiencies of CCFL (cold cathode fluorescent lamp) backlight technology and products on traditional LCD display devices, such as narrow color gamut, low energy utilization, high power consumption, and short life, people are always looking for With its alternative technologies and products, in this process, LED backlight technology products have been included in the selection of people.
Application area
Using LED as the backlight of the LCD TV, the main purpose is to improve the picture quality, especially the color saturation, the LED backlight technology display screen can obtain a wide enough color gamut, make up for the lack of display color of liquid crystal display devices, so that The ability to meet or even exceed Adobe RGB and NTSC color standard requirements, can reach NTSC raTIo more than 100%, of which Sony has introduced LED-backlit LCD TV panels, with special emphasis on the performance of bright red and dark green, can show more realistic than the previous way s color. At the same time, because of the planar light source characteristics of LED, the LED backlight can also realize the color and color adjustment functions of sub-regions that cannot be compared with CCFLs, thereby achieving more accurate color reproduction to meet the needs of the plane publishing and graphic design work. The dynamic adjustment can make the brightness and contrast can be dynamically modified to achieve better picture quality when displaying different pictures.
The following describes the five LED circuit design for readers to enjoy:
Driver for 60 white LEDs
The following figure shows an example. The LT3598 is used to drive 6 channels of 60 LEDs. The current of each LED string is set to 20mA. The CTRL pin and the PWM pin are responsible for the emulation dimming and digital dimming functions, respectively.
Driver for 36 white LEDs
The LT3598 is used to drive 4 channels of 36 LEDs. The current of each LED is set to 25mA. The LT3598 is designed to drive up to six strings of LEDs with an output voltage of up to 44V.
Driver for 20 white LEDs
The LT3598 is used to drive 4 channels of 20 LEDs. The current of each string of LEDs is set to 20mA. The LED dimming function can be implemented using an analog dimming circuit on the CTRL pin and a pulse width modulation dimming circuit on the PWM pin.
Automotive battery-powered driver for 20 LEDs
The LT3598 is used to drive 2 channels of 20 LEDs. The current of each string of LEDs is set to 90mA. The LT3598 can accurately regulate the LED current even when the input voltage is higher than the LED output voltage.
LED driver for 30 white LEDs
The LT3598 is used to drive 3 channels of 30 LEDs and the current of each LED is set to 60mA. The switching frequency can be set using an external resistor with an adjustable range of 200kHz to 2.5MHz.
The LT3598 is a general-purpose LED driver with a built-in power switch suitable for driving multiple strings of LEDs. With its robust fault detection capability, even high PWM dimming ratios can be provided. In addition, a voltage loop will regulate the output voltage when all LED strings are open. In addition, the advantage of LEDs as a backlight is that they can replace the use of color filters. The three-color RGB LED adopts the color sequential (alternal TIal) technology and utilizes the characteristics of human vision persistence to achieve full-color effects, and thus can replace color filters. Of course, this must be matched with the reaction speed of the liquid crystal. However, to achieve this realm, there are still many difficulties that must be overcome. The distinctive features of LED are high photoelectric conversion rate, high color saturation, small size, resistance to vibration, no toxic substances, low voltage power supply, safety to the human body, and long lifespan.
220W Medical Adapter,220W Medical Outlet Adapter,220W Medical Ivd Adapter,220W Breast Pump Adapter
Shenzhen Longxc Power Supply Co., Ltd , https://www.longxcpower.com