LinkSwitch-TN is specifically designed to replace all linear andcapacitor-fed (cap dropper) non-isolated power supplies in theunder 360 mA output current range at equal system cost whileoffering much higher performance and energy efficiency.LinkSwitch-TN devices integrate a 700 V power MOSFET,oscillator, simple On/Off control scheme, a high-voltage switchedcurrent source, frequency jittering, cycle-by-cycle current limit and thermal shutdown circuitry onto a monolithic IC. The start-upand operating power are derived directly from the voltage on theDRAIN pin, eliminating the need for a bias supply and associatedcircuitry in buck or flyback converters. The fully integratedauto-restart circuit in the LNK304-306 safely limits output powerduring fault conditions such as short-circuit or open loop,reducing component count and system-level load protectioncost. A local supply provided by the IC allows use of a nonsafetygraded optocoupler acting as a level shifter to furtherenhance line and load regulation performance in buck andbuck-boost converters, if required.