DC1557A

DC1557A demonstration circuit is a non-opto isolated flyback converter featuring LT3748EMS. 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 demo circuit can be easily modified for applications of different input, and output voltages/currents. 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. The LT3748EMS is well suited for a wide variety of industrial, automotive, medical, telecom, data-com applications, where regulated isolated output is required.

• 30V minimum input voltage
• 75V maximum input voltage
• 12.0V ±5% output voltage (VIN=30V to 75V IOUT=20mA to 1A)
• 1.0A output current (VIN=30V to 75V)