Products, Materials + Tools | Apr 27, 2011

Mean Well Announces New Series of DC/DC Constant Current LED Drivers - the LDD Buck Converters

MEAN WELL announced two kinds of encapsulated module type DC-DC Buck converter for LED driving purpose ~ LDD-L and LDD-H series. With constant current mode output, LDD-L features with 9~36VDC input and 2~32VDC output while LDD-H possesses wide range of 9~56VDC input and 2~52VDC output. Both series provide multiple output current options of 300mA/350mA/500mA/600mA/700mA/1A (LDD-H only) for LED system designers to choose from.

Main Features:
• Constant current (C.C.) mode output
• Wide input / Output range
• 97% high efficiency
• Built-in PWM dimming function
• Cooling by free air convection
• Protections : Short circuit /Over temperature
• UL94-V0 level plastic case
• Approval : FCC / CE
• Dimension(LxWxH) :
  LDD-L - 22.6x 9.9x 8.4mm
  LDD-H - 31.8x 20.3x 10.2mm
• 2 years warranty

LDD series are designed to be mounted on the system PCB of lighting fixture. Their typical deployment is to connect to the output of CV (constant voltage) mode AC-DC LED power supply for providing a constant current to drive LEDs. Take a typical LED lighting fixture with multiple LED strings internally as an example, using LDD series not only can maintain good current balance for each LED string and hence ensure the long life of LEDs, but also can save the effort of sorting the Vf value of LEDs. Besides, because of the independent constant current nature, failure in any LED string driven by the LDD series won’t affect the others, and each string can be connected for different number of LEDs according to system design requirements.

With non-isolated Buck topology design, LDD series possess up to 97% of extremely high efficiency and can operate between -40~+85℃of ambient temperature by only free air convection (up to 71℃ for 600mA~1A models). Built-in EMI filter, these LED drivers comply with EMI requirements per EN55015 lighting regulation without connecting any external EMI restraint components and are very convenient for PCB installations. The compact size also offers system designers great flexibility in PCB layout for power stage design. Other standard functions include PWM dimming, protections of short circuit and over temperature, wide range of input/output voltage. Besides, fully encapsulated packaging can help them withstand the influence of dust and moisture comes from all kinds of harsh environment. Suitable applications include street lighting, landscape lighting, tunnel lighting, household lighting, and all kinds of indoor/outdoor LED lighting.
 

page_peel