Sep 30 2010
Provider of power management technology solutions, National Semiconductor has launched the new LM3492 LED driver with headroom control that efficiently and accurately drives the current to two LED dimmable strings. The LM3492 LED driver reduces the expense, decreases system complexity, and maximizes system efficiency in automotive LCD backlighting applications.
The dynamic headroom control (DHC) feature of the LED driver adjusts the LED supply voltage via the boost converter feedback, to offer highest possible system efficiency. The DHC also enables one bill of materials for various LEDs present in a string. This is needed for backlight panels of various sizes. Thus the DHC decreases the overall cost and development time. The three embedded MOSFETs decrease cost and system complexity.
The LM3492 combines a two-channel current regulator and a boost converter, to cost-effectively drive two dimmable LED strings with power of up to 15 W, and a maximum output voltage of 65 V. The integrated current regulators enable high frequency and thin pulse width dimming signals to attain 1000:1 contrast ratio. The LM3492 incorporates a COMM pin that acts as a bi-directional input/output pin interface featuring an external MCU for diagnostic and command functions.