LED Driver Handles Higher Voltage Off-line Illumination
Wed, 02/09/2011 - 9:07am
Provided in standard SO-8 and high power dissipation exposed pad SO-8 packages, the AL9910 high brightness LED driver from Diodes Incorporated will support universal AC input voltages from 85 V to as high as 265 V. For interior and exterior off-line lighting products, the exposed pad SO-8 variant in particular helps raise reliability by minimizing temperature rise and, through its rugged high voltage process technology, by withstanding input voltage surges of up to 500V. System reliability is further improved by the devices’ in-built over-temperature protection. Driving LED arrays with a constant current to better control LED brightness, lighting spectrum and lifetime expectancy, the AL9910 will deliver an output of between a few milliamps and 1 A via an external MOSFET operating at a resistor programmable switching frequency up to 300 kHz. Removing the need for a start-up resistor, a built-in voltage regulator delivers a gate drive to match and protect the switching MOSFET; 7.5 V for the AL9910 and 10 V for the companion AL9910A. The AL9910 offers two separate dimming inputs for LED brightness control, a linear dimming input controlled by the application of a DC control voltage and a low frequency PWM dimming input accepting an external TTL compatible control signal with a duty ratio of 0-100 percent and at a frequency of up to a few kilohertz.