Simple-to-Use White LED Drivers Speed Backlight Designs
Now Available in Tiny (SC-70 and 2x2 MLP) Packages

As the trend in portable device displays moves from monochrome to full-color, the demand for compact, easy-to-use LED backlight solutions also grows dramatically. How can a designer get uniform brightness and brightness controls all in a small, easy-to-use, package that requires minimal external parts? The answer lies in Fairchild Semiconductor’s unique white LED driver family.

Illuminating Solutions for Handhelds
Fairchild, a leader in power management solutions, recently added seven white LED drivers to its product portfolio for handhelds. These low-dropout drivers provide a complete backlighting solution that covers all possible needs for cell phones, PDAs, pagers, and other portable devices.

Fairchild’s LED drivers’ built-in actively-matched current sources improve brightness matching with LED forward voltage compensation, without requiring external resistors. These integrated actively-matched current sources also enable the LED driver ICs to reach up to 97.5% efficiency. Since these new LED drivers use either minimal or no external components and come in small (SC-70, MLP, and TSOT) packages, they fulfill even the smallest PCB area requirements.

White LED Drivers Save Space, Reduce Part Count, and Provide Uniform Brightness
Fairchild’s extensive state-of-the-art LED driver family provides designers with a multitude of LED driver choices—including the most popular options and features for various lighting applications.

FAN5606
The FAN5606 LED driver allows designers to serially connect LEDs, using only one channel. A constant-current LED driver, the FAN5606 gives designers the flexibility of LED brightness control and features digital, analog, and PWM controls. The FAN5606 has a built-in Schottky diode, and requires no external ballast resistor—which minimizes external part count.

FAN5607
Fairchild’s FAN5607 LED driver provides precise current matching between LEDs, regardless of their forward voltage—perfect for applications that require precise current matching, such as a color LCD display. An adaptive charge pump allows the FAN5607 to generate a regulated output current from a battery with an input voltage between 2.7V to 5.5V, while achieving high efficiency over the entire input voltage range. The driver’s built-in auto-sense circuitry ensures the same high efficiency regardless of the number of LEDs. In addition, an external resistor can be used with the FAN5607 for the ultimate in design flexibility.

FAN5608
The powerhouse of white LED drivers, the FAN5608, gives designers the flexibility to connect a series of LEDs in two parallel channels. This flexibility, combined with an adaptive inductor-based DC/DC boost converter, makes the FAN5608 one of the most versatile LED drivers on the market. The FAN5608 also features all three brightness controls—digital, analog, and PWM. To improve efficiency, a Fairchild-proprietary control scheme automatically adjusts the drive voltage to the lowest possible level regardless of LED forward voltage mismatches.

FAN5609 and FAN5610
The FAN5609 and the FAN5610 drive up to four parallel LEDs, and feature proprietary current matching across the LEDs for brightness consistency. No external parts are needed for current matching. Unlike competitors’ products, these drivers feature a built-in forward voltage ( V_F) compensation circuit. This eliminates the need for V_F matching the LEDs, and gives designers the flexibility of using V_F-matched or V_F-unmatched LEDs. A built-in digital/analog converter provides digital and PWM brightness control. The FAN5609 also features a built-in switched capacitor boost converter to dynamically regulate output voltage.

FAN5611, FAN5612, FAN5613 and FAN6514
Simple to use and low in cost, the FAN5611, FAN5612, FAN5613, and FAN5614 are designed to drive V_F-matched LEDs, and feature both analog and PWM brightness controls. This family of drivers is also available in space-saving SC-70, MLP, and TSOT packages. The first driver in this family, the FAN5611, can drive up to four parallel-connected LEDS—in addition to supporting both analog and PWM brightness controls on the same control input for maximum ease-of-use. The FAN5612 can drive up to three LEDS, and has separate control inputs for analog and PWM brightness controls for the utmost in flexibility and performance. Similar to the FAN5612, the FAN5613 has separate control inputs for analog and PWM brightness controls, but it can drive up to four LEDs. Rounding out this group, the FAN5614 can drive two high-current LEDs—making it ideal for applications which require a higher current. Additionally, the FAN5612, FAN5613, and FAN5614 feature enable/shutdown control to further minimize power consumption.