The LNK305DN is a lowest component count energy-efficient offline Switcher IC specifically designed to replace all linear and capacitor-fed (cap dropper) non-isolated power supplies in the under 360mA output current range at equal system cost while offering much higher performance and energy efficiency. It integrates a 700V power MOSFET, oscillator, simple ON/OFF control scheme, a high-voltage switched current source, frequency jittering, cycle-by-cycle current limit and thermal shutdown circuitry onto a monolithic IC. The fully integrated auto-restart circuit in the LNK305 safely limits output power during fault conditions such as short-circuit or open loop, reducing component count and system-level load protection. A local supply provided by the IC allows use of a non-safety graded optocoupler acting as a level shifter to further enhance line and load regulation performance in buck and buck-boost converters, if required.
Feature
- Tight tolerances and negligible temperature variation
- High breakdown voltage of 700V provides excellent input surge withstand
- Frequency jittering dramatically reduces EMI
- High thermal shutdown temperature
- System level thermal overload, output short-circuit and open control loop protection
- Excellent line and load regulation even with typical configuration
- High bandwidth provides fast turn-ON with no overshoot
- Current limit operation rejects line ripple
- Universal input voltage range
- Built-in current limit and hysteretic thermal protection
- Higher efficiency than passive solutions
- Higher power factor than capacitor-fed solutions
- Entirely manufacturable in SMD
- Consumes typically 7/12mW in fly-back topology with external bias at 115/230VAC input with no-load
