No-Opto Isolated Flyback Converters

The no-opto isolated flyback parts from Linear need no opto-coupler or LT1431 shunt regulator for regulation. They sense the isolated output voltage directly from the primary-side waveform. This simplifies the design, allows for a smaller solution size and only requires one component crossing the isolation barrier. The load, line and temp drift is less than ±5%. Several off-the-shelf transformers are shown in the data sheets making it easy to complete the design.

No-Opto Isolated Flyback Converters
No-Opto Monolithic Parts (Internal Switch)
Part VIN Range Power Switch Max. POUT (W) Package
LT8300 6V-100V 0.23A/150V 2W SOT-23-5
LT8303 5.5V-100V 0.5A/150V 5W SOT-23-5
LT8301 2.7V-42V 1.2A/65V 6W SOT-23-5
LT8302 2.8V-42V 3.6A/65V 18W SO-8E
LT8304/-1 3V-100V 2A/150V 24W SO-8E
LT8315 18V-560V 300mA/630V 15W TSSOP-20 (16)
No-Opto Controller Parts (External Switch)
Part VIN Range Max. POUT (W) Description Package
LT3748 5V-100VDC 80-100 No-Opto Flyback Controller MSOP-16 (12)
LT8309 4.5V-40VDC 80-100 Flyback Synchronous Rectifier Driver SOT-23
LT3798 20V-400VDC/90V-400VAC 80-100 No-Opto Flyback Controller with PFC MSOP-16