DESCRIPTION
The LT ®1425 is a monolithic high power switching regulator specifically designed for the isolated flyback topology. No “third winding” or optoisolator is required; the integrated circuit senses the isolated output voltage directly from the primary side flyback waveform. A high current, high efficiency switch is included on the die along with all oscillator, control and protection circuitry.

FEATURES
■ No Transformer “Third Winding” or Optoisolator Required
■ ±5% Accurate Output Voltage Without User Trims (See Circuit Below)
■ Resistor Programmable Output Voltage
■ Regulation Maintained Well Into Discontinuous Mode (Light Load)
■ Optional Load Compensation
■ Operating Frequency: 285kHz
■ Easily Synchronized to External Clock
■ Available in 16-Pin Narrow SO Package

APPLICATIOUNS
■ Isolated Flyback Switching Regulators
■ Ethernet Isolated 5V to –9V Converters
■ Medical Instruments
■ Isolated Telecom Supplies