New Industry Products

Fairchild LED Drivers Enable Design Flexibility and Extend Battery Life in Mobile Handsets

June 07, 2010 by Jeff Shepard

Fairchild Semiconductor states that it is bringing designers of mobile handsets, gaming devices, MP3 players and other small display applications LED drivers that deliver 92% peak efficiency, extending battery life. The FAN5701 and FAN5702 are 1x to 1.5x charge pump-based 180mA, 6-channel LED drivers that backlight TFT LCD displays in mobile electronics. Their low transition voltage from 1x to 1.5x mode allows them to operate in 1x mode for a longer time period, achieving higher efficiency. Both LED driver products can be configured to support clamshell form factor mobile handsets that have both main and secondary displays.

The FAN5702 is a configurable, 180mA, 6-channel LED driver with I²C interface and provides the following features: design flexibility, enabling it to be used in different lighting applications beyond backlight LCD displays such as Red-Green-Blue (RGB) indicator/fun lights; an I²C interface, allowing the designer to control the LED outputs individually (2,1,1,1,1 format) and group them together or separately depending upon the design requirements; greater brightness control by having each LED output supporting 64 logarithmic-dimming steps and eliminating distortion especially at lower brightness levels; an enable pin, providing the baseband chipset direct control to turn it on or off; a PWM signal input to support dynamic backlight control (DBC). DBC is a feature that automatically adjusts the brightness of the LEDs depending upon the image content, which, in turn, helps reduce power consumption; a DBC feature with an ambient light sensor providing both dynamic backlight and ambient light control, saving up to 50% in power consumption.

The FAN5701 is a cost-effective LED driver that uses two PWM inputs to control the brightness of a grouping of four and two LED outputs. It is well suited for applications where there is a requirement to backlight two LCD displays or to drive a high brightness LED for low power camera flash in mobile handsets.

The FAN5701 and FAN5702 are housed in compact 16-bump WL-CSP and 16-lead UMLP packages to accommodate the slimmer and smaller form factor of today’s portable designs. In WL-CSP form factor the FAN5701 and FAN5702 occupy 2.56mm2, which is one of the smallest lighting solutions available in the market today and are instrumental in conserving PCB space.

The units are price (each 1,000pcs) as follows: FAN5701 = US$0.72, and FAN5702 = US$0.95, with a delivery of 12 weeks ARO.