LNK304PN IC - Power Integrations - AC-DC Off Line Switcher IC

The LNK304PN 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 Figure 1. Typical Buck Converter Application (See Application Examples Section for Other Circuit Configurations).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 fly back converters. The fully integrated auto-restart circuit in the LNK304 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. Features:- • Lowest cost and component count buck converter solution • Fully integrated auto-restart for short-circuit and open loop fault protection – saves external component costs • 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) Specification:- Symbol Parameter Min Type Max Units VBP BYPASS Pin Voltage 5.55 5.8 6.10 V VBPH BYPASS Pin Voltage Hysteresis 0.8 0.95 1.2 V tON(MIN) Minimum On Time 280 360 475 ns tLEB Leading Edge Blanking Time 170 215 ns TSD Thermal Shutdown Temperature 135 142 150 °C TSHD Thermal Shutdown Hysteresis 75 °C Related Document:- LNK304PN IC Data Sheet