Leadis Technology Introduces A Six-Channel LED Driver With I2C Interface
Targeted at mobile backlighting applications, the latest LED driver device supports up to six LEDs with a maximum current of 32mA per channel. The industry-standard I2C serial interface product joins the previously announced six-channel PWM and 1-wire interface products to give mobile phone design engineers more flexibility with a new set of performance/interface choices.
"Mobile phone design houses everywhere are adding content-rich multimedia applications. This creates the need for larger displays, requiring six LEDs instead of four for illuminating the display's backlight," said Adolfo Garcia, Senior Director of LED Drivers at Leadis Technology. "These multimedia applications also create a need for more efficient LED drivers in order to conserve battery power. Whether mobile cell phone designers prefer a PWM, 1-wire, or now an I2C serial interface, Leadis is well positioned to support this new six-channel market. Moreover, Leadis' LED drivers will continue to address and improve on the most important requirement in these mobile appliances: longer battery life."
Leadis' ultra low voltage dropout PowerLite Current Regulator provides a typical transition threshold of only 50mV, allowing the device to stay in a charge-pump driver's highest-efficiency mode longer than competing devices. Additionally, this patent-pending technique also solves one of the most significant problems associated with charge-pump based LED drivers, namely the transition between the high-efficiency state (1x-mode) and the lower efficiency states. By lowering the dropout voltage of the driver to only 50mV, battery life can be extended by up to 10%.
About the LDS8860
The LDS8860 is a high-efficiency 1x/1.5x/2x fractional charge pump with programmable current in six LED channels. The addition of an ultra low dropout PowerLite(TM) Current Regulator increases the LDS8860's efficiency up to 91%. Low noise and input ripple performance is achieved by operating the charge pump at a constant switching frequency of 1 MHz, which allows the use of small external ceramic capacitors.
The LED channels are configured into three independent banks, each containing 2 matched channels. Each pair can be separately programmed from zero to 32mA, in 0.5mA increments, using the I2C serial interface. Any individual channel can be disabled, while others remain active. The device is available in a 16-lead TQFN 4mm x 4mm or a 3mm x 3mm package with a maximum height of 0.8mm.
SOURCE: Leadis Technology, Inc.