LED TFT Display Module

According to different display sizes, LED number may range from 10 inches monitor 30, the large flat-screen TV over 1000. Because these LED light output depends on the current, so strictly meet all the LED current demand is very important, although as with all other electronic components, the characteristics of each LED are not the same.Graphic LCD Display
If you do not minimize these differences, then the display will be a significant unevenness in brightness. Driver IC for current control, the current changes in the current matching specification to maintain a small specified range. For notebooks and monitors, the ideal goal is ± 2% or less; right TV is ± 1%.
Because many of the properties of LED with the LED current will change, so the brightness adjustment function should use the pulse-width modulation (PWM) control to achieve and maintain on-state with a constant current. While some systems use an external PWM signal (for example, some laptops use direct PWM control), but with onboard PWM generator driver chip is usually a better choice. Such devices do not require an external PWM generator can simplify system design. Some driver IC supports both ways.
Many existing backlighting applications used are lower than the PWM frequency 1kHz, in some cases, if a low-cost ceramic capacitors, may produce the human ear can hear noise. PWM frequency by choosing to support a wide range (including those that the human ear can not hear frequencies) of the device, to avoid this problem.128x32 oled