Recently, Leadis Technology, Inc., announced sample availability of the LDS8160, a new LED driver featuring its proprietary LED-Sense Temperature Compensation engine and its patent-pending PowerLite Current Regulator.

The former monitors the in-situ temperature on each LED and independently optimizes the LED current for best luminosity vs. temperature performance. The latter ensures a low drop out voltage on each LED channel of typically 25mV across the full operating current range. To minimize standby current, the LDS8160 also features an additional low-power standby mode, where the supply voltage of the device is switched to 1.8V. The LDS8160 is controlled through a high-speed I2C interface. Targeted at mobile backlighting applications, the LDS8160 supports up to six white LEDs or up to two RGB LEDs, with a maximum current of 25mA per channel.

Mobile phones have evolved from voice-centric devices to multi-media platforms. 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.