Power Integrations' (www.powerint.com) DER-305 describes a non-isolated, high-efficiency, high power factor (PF) LED driver that drives a nominal LED string voltage of 50 V at 200 mA from an input voltage range of 185 VAC to 265 VAC.

DER-306 achieves similar performance, operating from low-line input - 90 VAC to 135 VAC. Both LED drivers utilize the LNK460VG from the LinkSwitch-PL family of ICs.

Key features and benefits include:
• Single-stage power factor correction combined with constant current (CC) output
• Low-cost, low component count, small size and single-sided PCB
• Highly energy efficient
o DER-305: >91% at 230 VAC input for 50 V LED Load
o DER-306: >89% at 115 VAC input for 36 V LED Load
• Integrated protection and reliability features
o Single shot no-load protection / output short-circuit protected with auto-recovery
o Auto-recovering thermal shutdown with large hysteresis protects both components and PCB
o No damage during brown-out conditions

The topology used is a single-stage non-isolated buck that meets the stringent space and efficiency requirements for this design. LinkSwitch-PL based designs provide a high power factor (>0.9).