LED Controller Features In-Situ Temperature Compensation

Two new LED controllers—the LDS9001 and LDS9003—feature a patent pending LED-Sense temperature-compensation engine. This innovative feature allows for direct in-situ monitoring of the LED junction temperature without the need for an external temperature sensor, thereby optimizing LED brightness and reliability throughout the LED's full operating temperature range. Targeted at high-power lighting applications, the LDS9001 and 9003 can independently monitor one and three LEDs, respectively. With LED-Sense, every few seconds the LED junction temperature is measured in-situ and the current is adjusted on each LED channel using a programmable current-versus-temperature de-rating profile. This optimizes luminosity while ensuring reliable LED operation. System designers are therefore able to reduce guardbands they typically employ, while safely biasing the LEDs at higher currents over the LED's operating temperature range. As the temperature of the system increases above a pre-set point, the LD9001/9003 intelligently reduces the LED drive current, thereby ensuring that the LEDs operate in a specified safe temperature zone. Both products can support WLED lighting, automotive, and signage applications. Since the LDS9003 supports multi-point thermal monitoring, it can also be used for multi-color LED applications, such as RGB. Eight I²C-programmable registers let users define the temperature de-rating profile as a function of the specific LED used in the design. The LDS9001 and LDS9003 are offered in 3-mm x 3-mm 8-pin DFN and 16-pin TQFN packages, respectively. LEADIS TECHNOLOGY INC., Sunnyvale, CA. (408) 331-8600.