Mobile phones have evolved from voice-centric devices to multi-media platforms. Whereas five years ago users would use their mobile phones primarily for voice communication, today users exchange text messages, read and write emails, share photos, connect to the Internet, record videos and activate integrated GPS-Navigation systems from their mobile phones. These applications all center around the mobile phone's display. Consequently, the user expectations in terms of display-performance have increased. For example, users now expect excellent outdoor display readability, which is a challenge given the current required to drive the backlight unit to satisfactory display contrast and color saturation. One solution to this problem is to utilize RGB diodes in the backlight unit. These diodes require temperature compensation in order to keep their white color coordinates constant, a problem that the LDS8160 is designed to solve.
The LDS8160 offers superior temperature control through its proprietary LED-Sense Temperature Compensation engine. Existing solutions either place a sensor in the proximity of the LEDs, which increases cost and reduces the available footprint of the phone, or rely on measuring temperature only inside the LED driver chip, which can result in inaccurate current readings. The LDS8160, however, measures the temperature of each LED at the diode itself. This in-situ measurement doubles the accuracy and does not require extra sensor components on the board. Every few seconds, the measured temperature is fed into Leadis' proprietary compensation engine that adjusts the current on each LED channel in order to optimize luminosity, color saturation and to prevent system overheating. Sixteen I2C-programmable registers for each of 3 channel banks let users define the compensation curve as a function of the specific LED Diode used in the design.
The LDS8160 offers multiple advantages for designers of portable applications. For longer battery life, efficiency is increased up to 98% by the inclusion of the PowerLite Current Regulator and the exclusion of boosting circuits that are not needed with most of today LEDs. The ultra low dropout PowerLite Current Regulator provides a transition threshold of 25mV, allowing customers to adopt any LED with a Vf lower than 3.4V. For improved dynamic brightness control, three 12-bit logarithmic PWM generators are integrated on chip. These generators allow customers to send a dimming command through the I2C interface without having to keep "pulsing" a PWM bus. This innovation dramatically improves the power consumption of the system, especially if frequent dimming is required. The LDS8160 is offered in a tiny 3mm x 3mm 16-pin TQFN package and in an ultra small WCSP 3x4 ball grid package with 0.4mm pitch.
"We are pleased to bring to the market our first LED Driver featuring our proprietary Temperature Sensing and Compensation Engine," said Donato Montanari, Vice President and General Manager at Leadis Technology. "Whereas the LDS8160 is tailored specifically for the mobile market, our Temperature Sensing and Compensation Engine is an extremely accurate and flexible IP block that can be ported across different application markets. We are expecting to introduce temperature compensated devices for the notebooks market soon. With increasing customer demand for improved outdoor readability, the ability to control backlight unit temperature in a dynamic, accurate and fast manner gives mobile phone designers more flexibility in tackling this challenging problem."
About the LDS8160
The LDS8160 is a dual-output RGB or 6-channel white LED driver with three integrated temperature compensation circuits for each bank of two LED drivers. It can support both RGB LED and WLED backlighting, keypad, and other lighting functions in portable applications. Three programmable, 8-bit DACs set the current level for each LED bank (A, B, & C) from 0 to 25mA in 0.125mA steps. Each channel contains a linear LDO current regulator (driver) in a common cathode (i.e., current source) topology. The LDO drivers have a typical dropout voltage of 25mV at maximum rated current. This provides a low power/low EMI solution in Li-ion battery applications without voltage boosting and associated external capacitors and components. Three 12-bit PWM generators with "smooth" logarithmic control support Temperature vs. LED Luminosity adjustments, as well as RGB color correction and dimming. These PWM generators are programmable via an I2C serial interface. User programmed 8-bit codes are converted to 12-bit resolution logarithmic steps of ~0.17 dB per step. The PWM frequency is ~280 Hz to minimize noise generation.
For more information, visit www.leadis.com.
About Leadis Technology, Inc.
Leadis Technology, Inc., headquartered in Sunnyvale, California, designs, develops and markets analog and mixed-signal semiconductors that enable and enhance the features and capabilities of portable and consumer electronics devices. Leadis' product offerings include color display drivers, which are critical components of displays used in mobile consumer electronic devices; LED drivers, which provide controlled levels of current required to drive light emitting diodes in diverse applications including mobile backlight units; power management ICs including LDOs, LDO controllers, shunt references, thermal switches, current regulators, and battery charger controllers; and touch controller ICs, which enable highly reliable touch-based input controls and attractive industrial design options for both mobile and non-mobile applications.
Certain statements in this press release including, but not limited to, the features and benefits of Leadis' new LDS8160 LED driver, including its LED-Sense Temperature Compensation engine and PowerLite Current Regulator are forward-looking statements that are subject to risks and uncertainties that could cause results to be materially different than expectations. Such risks and uncertainties include, but are not limited to, lack of market adoption of the LDS8160, delays associated with ramping new products into production, lack of market acceptance of the LDS8160 or the LED-Sense Temperature Compensation engine and PowerLite Current Regulator technologies, that pending patent applications will not result in issued patents or that any issued patents may not be sufficiently broad to protect our proprietary technologies, delays in the integration of our products into consumer electronic devices, our reliance on third-party manufacturers, general mobile handset and semiconductor industry trends, and other risks detailed from time to time in Leadis' reports filed with the Securities and Exchange Commission including its Form 10-K for the year ended December 31, 2007 and Form 10-Q for the quarter ended September 30, 2008. Leadis disclaims any obligation to update these forward-looking statements.
Contact Information: Julie Pestka-Schardt Leadis Technology, Inc. Tel: 408.331.8603 Or Paul Schneider George Cohen Communications, Inc. Email: Email Contact Tel: 215.702.9784