To serve the steady migration from cold cathode florescent (CCFL) backlighting of LCD displays to LED backlights, TDK-Lambda has launched its new ALD Series of multi-output dc-dc backlight LED drivers. These drivers are specifically designed for LED backlighting of LCD displays that are now used in industrial and consumer applications. The series includes models for backlight LEDs arranged in 2, 3 and 4 string configurations. The drivers feature wide-range dimming controls with resistive, analog or PWM inputs that provide smooth LED brightness control. Each ALD output provides up to 140mA of constant-current drive to backlighting LEDs that can be connected in series and parallel configurations.
The ALD drivers are designed to operate with an input voltage of from 10.8 to 13.2VDC and have a maximum open-circuit output voltage of 42 to 44VDC. The series are ultra thin (5.0 to 5.5mm) to facilitate easy mounting behind LCD screens with a minimum of space. The 2 and 3 string models measure only 21.5mm high by 85mm long and the 4 string drivers are 50mm high by 100mm long.
Other features include a Remote On/Off input and an Overvoltage Alarm output. The Overvoltage Alarm serves as a LED open detector. These drivers are convection cooled and designed to operate in ambient temperatures from ranging from -30°C to +85°C without deratings. Typical operating efficiencies are 90%, which substantially reduces power consumption and unwanted heat.
The ALD Series are ideal for backlighting of LCD panels used in vending machines, industrial touch screens, POS terminals and programmable controllers, to name a few. This series is available now and priced at $18.75 in 1000 piece quantities.