LT3825 Datasheet | Linear Technology

Features n LT3825 Isolated No-Opto Synchronous Flyback Controller with Wide Input Supply Range DESCRIPTION The LT®3825 is an isolated switching regulator controller designed for medium power flyback topologies. A typical application is 10W to 60W with input voltage limited only by external power path ponents. A third transformer winding provides output voltage feedback. The LT3825 is a current mode controller that regulates output voltage based on sensing secondary voltage via a transformer winding during flyback. This allows for tight output regulation without the use of an optoisolator, improving dynamic response and reliability. Synchronous rectification increases converter efficiency and improves output cross regulation in multiple output converters. The LT3825 operates in forced continuous conduction mode which improves cross regulation in multiple winding applications. Switching frequency is user programmable and can be externally synchronized. The part also has load pensation, undervoltage lockout and soft-start circuity. L, LTC and LT are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 6948466, 5841643. Senses Output Voltage Directly from Primary Side Winding- No Optoisolator Required n Synchronous Driver for High Efficiency n Input Voltage Limited Only by External Power ponents n Accurate Output Regulation Without User Trims .. n Switching Frequency from 50k Hz to 250k Hz n Synchronizable n Load pensation n Programmable Undervoltage Lockout n Available in a Thermally Enhanced 16-Lead TSSOP Package APPLICATIONS n n n n Isolated Medium Power (10W to 60W) Supplies Isolated Tele, Medical Converters Instrumentation Power Supplies Isolated Power over Ethernet Supplies TYPICAL APPLICATION EFFICIENCY (%) Efficiency 92 90 36VIN 88 48VIN 72VIN 48V to 3.3V at 12V Isolated Supply VIN+ 36V TO 72V 100p F 28.7k T1 3.01k 402k 2.2μF...