Backlight Controllers for Notebook Computer LCD Displays
Microsemi added two backlight controllers for notebook computers, additions to its portfolio of devices that power CCFLs in LCD displays. Designated the LX1693 and LX1697, the backlight controllers are optimized for the wide input voltage range found in notebook display applications and support Intel's Display Power Saving Technology that adjusts brightness as a function of video content. The advanced architecture of the LX1693 includes all the support components needed to integrate the growing consumer demand for notebook computers having "Automatic Brightness Control." This system level power saving technique designed into the LX1693 uses available Microsemi ambient light sensors with a spectral response that closely emulates the human eye. Both controllers feature the company’s advanced resonant full bridge topography in designs that extend the life of CCFL lamps, control EMI emissions and maximize efficiency. On-chip regulators allow direct operation from the notebook's battery, without the need of an external 5V supply from its system. Input voltage for the two controllers can range from 7V to 25V. Dimming can be analog, digital, or a combination of the two. Extensive fault detection features include open lamp, over-voltage, short circuit, over-current and over-temperature protection. Both controllers are RoHS Compliant and Pb-free.