POWER INTEGRATIONS LNK305PN Off-Line Switcher IC, DIP-8

The POWER INTEGRATIONS LNK305PN is a LinkSwitch-TN series, energy-efficient off-line switcher IC designed as a high-performance, low component count replacement for linear and capacitor-fed (cap dropper) power supplies in applications requiring up to 360mA output current. It integrates a 700V power MOSFET, control circuitry, and protection features into a single monolithic IC, simplifying design and reducing overall system cost while significantly improving efficiency.

This device derives its start-up and operating power directly from the voltage on the DRAIN pin, eliminating the need for a separate bias supply in buck or flyback converter topologies. Its fully integrated auto-restart circuit provides robust protection against output short-circuits and open control loop faults, enhancing system reliability and safety while minimising external component requirements.

Key Features & Performance

• Universal Input: Operates from a wide 85V to 265V AC input range, making it suitable for global applications.
• High Integration: Combines a 700V MOSFET, oscillator, on/off controller, and thermal shutdown into one IC for a compact solution.
• Enhanced Efficiency & Power Factor: Delivers significantly higher efficiency and power factor compared to traditional passive solutions.
• Reduced EMI: Integrated frequency jittering dramatically reduces electromagnetic interference (EMI) by approximately 10dB.
• Comprehensive Protection: Features built-in cycle-by-cycle current limiting, hysteretic thermal protection, and system-level safeguards against overloads.
• EcoSmart™ Technology: Consumes minimal standby power—typically 50mW at 115VAC and 80mW at 230VAC in a self-powered buck configuration with no load—helping designs meet stringent international energy standards including CEC, Energy Star, and EU requirements.

Design Advantages

The LNK305PN supports