New white LED driver to achieve digital pulse dimming

Taiwan Li (Jin Qi) technology (RichTek Technology) recently launched a series of white LED driver -RT9285 innovative design, RT9285 provides a simple pulse dimming technology, the system only needs to provide a wide and narrow different digital pulse, easy to realize the output brightness adjustment. It also integrates the Schottky diode (Diode) in the circuit, so that the number of components of the system, radio frequency interference smaller. While simplifying the circuit and software design of the whole system, it also provides the excellent performance of the electromagnetic interference. White LED backlight driver and OLED power supply for portable electronic products

The backlit LCD screen of the portable electronic products are mainly white LED, white LED brightness with the current is proportional to the RT-9285 series of LED architecture, the highest 5 white LED series can provide the required voltage, and can be connected in series with a resistor to set the maximum LED current, can cover all the small size LCD screen backlight required, and ensure the uniformity of the brightness of LED. In order to meet the needs of backlight with different brightness, RT-9285 provides pulse dimming technology, simplifies the design of the circuit, and provides the characteristics of the electromagnetic interference.

In addition to the supply of white LED drive current, RT-9285 can also be used as an organic light emitting diode (OLED) power supply, by setting the resistance divider, RT-9285 can provide constant voltage output as the OLED power supply.

The conversion efficiency of RT-9285 is up to 85%, which can reduce the current consumption and prolong the battery life, and the built-in Schottky diode can reduce the required components and the complexity of the system. Built in soft start (Soft start) function can reduce the inrush current (Inrush current), over voltage protection (OVP) and over current protection (OCP) can determine the system working in normal condition.

RT9285 using WDFN2x2-8L and TSOT-23-6 minimal packaging, has now begun to provide samples. For further information, please refer to Li (Jin Qi) science and technology website: www.richtek.com.