Fairchild Semiconductor has introduced new, sophisticated light-emitting diode (LED) drivers called the FAN5701 and the FAN5702 for MP3 players, gaming devices, mobile handsets and other display applications. The FAN5701 and the FAN5702 LED drivers offer 92% peak efficiency, which help extend the life of batteries.
The LED drivers are 1-1.5x charge, 6-channel, 180 mA devices that backlight thin film transistor liquid crystal display (TFT LCD) displays in portable electronic products. The low-transition voltage of the LED drivers i.e. from 1x to 1.5x mode enables them to function in 1x mode for an extended period of time, which helps achieve optimum efficiency. The FAN5701 and the FAN5702 can be configured to support clamshell form factor cellular phones that feature main and secondary displays.
The FAN5702 LED driver features an I2C interface, which enables designers to control the LED outputs depending upon the design specifications. The FAN5702 offers ultimate design flexibility, which means that in addition to the backlight LCD displays, the FAN5702 can also be utilized in varied lighting applications such as Red-Green-Blue (RGB) fun/indicator/lighting products.
The FAN5702 allows advanced brightness control through individual LED output that supports 64 logarithmic-dimming steps. The LED driver also removes distortion at reduced brightness levels. The FAN5702 features a pin that enables the base-band chipset to turn it on and off. A pulse-width modulation (PWM) signal input supports backlight control (DBC), which automatically adjusts the LED brightness depending upon the content of the image. This feature reduces energy usage. An ambient light sensor and a DBC offer ambient and backlight control, which save about 50% of energy usage.
The FAN5701 LED driver utilizes two pulse-width modulation inputs, which control the brightness of LED outputs. The FAN5701 can be used in LCD displays and low-power camera flash in cellular phones.
The FAN5702 and the FAN5701 are available in 16-lead UMLP packages as well as in compact 16-bump WL-CSP housing in order to fit in the small form factor of current mobile designs. In the WL-CSP form factor, the FAN5702 and the FAN5701 occupy 2.56mm2, which help conserve PCB space.
The FAN5702 and the FAN5701 in WL-CSP form factor are under production and the UMLP package version of the LED drivers will be introduced in June 2010.
Source: http://www.fairchildsemi.com