The LT1725IS#PBF is a monolithic Switching Regulator Controller specifically designed for the isolated flyback topology. It drives the gate of an external MOSFET and is generally powered from a third transformer winding. These features allow for an application input voltage limited only by external power path components. The third transformer winding also provides output voltage feedback information, such that an optoisolator is not required. Its gate drive capability coupled with a suitable external MOSFET can deliver load power up to tens of watts. The LT1725 has a number of features not found on most other switching regulator ICs. By utilizing current-mode switching techniques, it provides excellent AC and DC line regulation. Its unique control circuitry can maintain regulation well into discontinuous mode in most applications. Optional load compensation circuitry allows for improved load regulation.
Drives external power MOSFET with external ISENSE resistor
Application input voltage limited only by external power components
Senses output voltage directly from primary side winding - no optoisolator required
Accurate regulation without user trims
Regulation maintained well into discontinuous mode
(EN)
