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 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 flyback converters.
Feature
- Lowest cost and component count buck converter solution
- Fully integrated auto-restart for short-circuit and open loop fault protection - saves external component costs
- 66kHz operation with accurate current limit - allows low cost off-the-shelf 1 mH inductor for up to 120 mA output current
- High breakdown voltage of 700 V provides excellent input surge withstand
- 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 (85VAC to 265VAC)
- Built-in current limit and hysteretic thermal protection
