Adjustable LED driver chip TFT Display Module

Driver chip LED brightness adjustment can be achieved when the granularity or accuracy depends on the chip digits. The higher the number, PWM signal can be divided into smaller increments, it can provide better brightness control.

The specification of the driver chip, PWM high / low transition time should be as short as possible, so as to ensure that even in case of a small duty cycle of the output square wave pulse is accurate. This is essential to ensure tighter current matching and linearity better dimming range is essential.
In the high PWM rates, such as 25kHz, can provide low a least significant bit (LSB) of the linear brightness adjustment of the driver IC to provide the best performance. However, the conversion rate is not too fast, because of the higher frequencies may cause oscillation and other forms of electromagnetic interference (EMI). A rate of about 50ns to meet this demand, while the efficiency is maximized.I2C Lcd Module
While some LED driver IC without a communication interface, but in many backlighting applications which device is best with this feature, but this kind of interface for devices with onboard PWM generator is particularly important. This interface simplifies programming, fault monitoring, and other functions in the Inter-Integrated Circuit (I2C) type is the most common. For those who need to update the system in terms of speed, low-voltage differential signaling (LVDS) interface, such as becoming more common.
Boost converter with an on-board driver chip is no longer the need for external circuitry to achieve this functionality. In addition, it is best to use an integrated switch, because it eliminates electromagnetic interference caused by the onboard interconnection possibilities to simplify the bill of materials (BOM), saving PCB area, and no longer require the designer to specify the driver chips can be a good match transistors. The use of the boost frequency variation range is very wide, and sometimes is programmable.
Higher frequency (such as 1.2MHz) have the advantage of a smaller inductor and capacitor. Dynamic Headroom Control (DHC) mode is another important function. It is connected to the boost converter to measure all of the LED strings, and automatically adjust the output voltage to drive these LED string the minimum required voltage value. Doing so makes the current mirror of the linear drive the voltage drop decreases the chip, the drive power reduced, so that the overall efficiency increased.
Optical loop control with driver chip allows designers to use the LED light sensor to compensate for changes in temperature and lifetime. Thermal sensors can also be used to compensate for thermal effects. Optical sensors can also be used to adjust the brightness of the backlight as a response to changes in the surrounding environment, in a dark environment to adjust the display brightness.
 Ideal LED driver IC chips should contain many of the drive and the LED for protection. In an LED or LED string when a failure occurs, LED short / open circuit protection allows the backlight to continue working. In addition, over-voltage, over-current and thermal protection for the driver chips and LED provide the necessary protection. Undervoltage lockout chip is used to ensure that the drive will not work outside the specified range, because that may cause the device unable to work properly.3.5 TFT display module
With a lot of features on-chip driver circuit chip can reduce the required PCB area and bill of materials. They also reduce the design complexity, since the designer is no longer necessary to design an external circuit, or to whom to select the best components. Of course, in different applications of the importance of each feature will be different, and was selected by the driver IC is based on its price compared with the performance of the system and elected.