Date
12/05/2012
Power Integrations has announced two new reference designs describing high-efficiency, non-isolated, high-power-factor drivers for LED-based T8 tube replacements. The designs feature low component count and leverage simple magnetics and single-sided boards yielding power densities of 14.2 W/in3. The DER-337 (high-line) and DER-345 (low-line) reference designs use the LNK460KG LED driver from the company's LinkSwitch-PL IC family. The circuits use single-stage non-isolated topologies, which result in a profile of only 8 mmsmall enough to mount behind the LEDs in the T8 tube. The buck-boost (DER-337) or buck (DER-345) configurations deliver power factors greater than 0.9 and low THD, meeting EN61000-3-2 C limits. The designs are EMI compliant, easily meeting the EN55015 class B specification. The integrated single-stage driver IC controls both PFC and constant-current output resulting in an application circuit that uses fewer than 30 components. Both drivers deliver 20 W (85 V at 240 mA) at an efficiency as high as 92 % (DER-337) and 89 % (DER-345). The reference-design documentation sets include the LED driver specification, schematic, PCB details, bill of materials, transformer documentation, and detailed performance characteristics. Comments Andrew Smith, product marketing manager at Power Integrations, "The LED tube market is moving to non-isolated drivers, which boost system efficiency and reduce the temperature of the driver board and components. These boards use approximately half the number of components of isolated designs and are typically 3 to 4% more efficient. With a high PF and low THD they perfectly suit commercial and industrial lighting applications anywhere in the world." Power Integrations DER-337 reference-design deeplink DER-345 reference-design deeplink