AC/DC offline switch, 85-265 VAC, 120mA, SO-8C-7

LNK302/304-306 LinkSwitch-TN Family
Lowest Component Count, Energy-Efficient Off-Line Switcher IC

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 - save external component costs
- LNK302 uses a simplified controller without auto-restart for very low system cost
- 66 kHz operation with accurate current limit - 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)
- 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™- 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

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 nonsafety graded optocoupler acting as a level shifter to further enhance line and load regulation performance in buck and buck-boost converters, if required.

Applications
- Appliances and timers
- LED drivers and industrial controls