Demonstration circuit 1557A is an Non-Opto Isolated Flyback Converter featuring LT3748EMS. It is designed for 12V output from a 30V to 75V DC input. The output current is up to 1A. The part senses the isolated output voltage directly from the primary side flyback waveform during the off time of the power switch. No third winding, opto-coupler or signal transformer is required for regulation. A minimum load of approximately 2% of maximum load is required on the output.
The LT3748EMS is a high input voltage isolated flyback controller operating with input supply voltages from 5V to 100V. The LT3748EMS utilizes boundary mode operation to provide a high efficiency, small size solution with improved load regulation of ±5% over the full line, load and temperature ranges.