Description
LinkSwitch-TN is specifically designed to replace all linear and capacitor-fed (cap dropper) non-isolated power supplies in the under 360 mA output current range at equal system cost while offering much higher performance and energy efficiency.
LinkSwitch-TN devices integrate a 700 V 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 start up and operating power are derived directly from the voltage on the DRAIN pin, eliminating the need for a bias supply and associated circuitry in buck or flyback converters. The fully integrated auto-restart circuit in the LNK304-306 safely limits output power during fault conditions such as short-circuit or open loop, reducing component count and system-level load protection cost. 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.
Product Highlights
Cost Effective Linear/Cap Dropper Replacement
⢠Lowest cost and component count buck converter solution
⢠Fully integrated auto-restart for short-circuit and open loop fault protection â saves external component costs
⢠LNK302 uses a simplified controller without auto-restart for very low system cost
⢠66 kHz operation with accurate current limit â allows low cost off-the-shelf 1 mH inductor for up to 120 mA output current
⢠Tight tolerances and negligible temperature variation
⢠High breakdown voltage of 700 V provides excellent input surge withstand
⢠Frequency jittering dramatically reduces EMI (~10 dB)
â minimizes EMI filter cost
⢠High thermal shutdown temperature (+135 °C minimum)
Much Higher Performance over Discrete Buck and Passive Solutions
⢠Supports buck, buck-boost and flyback topologies
⢠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 (85 VAC to 265 VAC)
⢠Built-in current limit and hysteretic thermal protection
⢠Higher efficiency than passive solutions
⢠Higher power factor than capacitor-fed solutions
⢠Entirely manufacturable in SMD
EcoSmart娉 Extremely Energy Efficient
⢠Consumes typically only 50/80 mW in self-powered buck topology at 115/230 VAC input with no load (opto feedback)
⢠Consumes typically only 7/12 mW in flyback topology with external bias at 115/230 VAC input with no load
⢠Meets California Energy Commission (CEC), Energy Star, and EU requirements
Applications
⢠Appliances and timers
⢠LED drivers and industrial controls
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