Linear Technology's LT3748 is a switching regulator controller specifically designed for the isolated flyback topology and capable of high power. It drives a low side external N-channel power MOSFET from an internally regulated 7V supply. No third winding or opto-isolator is required for regulation, as the part senses the isolated output voltage directly from the primary-side flyback waveform.
The LT3748 utilizes boundary mode to provide a small magnetic solution without compromising load regulation. Operating frequency is set by load current and transformer magnetizing inductance. The gate drive of the LT3748, combined with a suitable external MOSFET, allow it to deliver load power up to several tens of watts from input voltages as high as 100V.
- 5V to 100V input voltage range
- 1.9A average gate drive source and sink current
- Boundary mode operation
- No transformer third winding or opto-isolator required for regulation
- Primary-side winding feedback load regulation
- VOUT set with two external resistors
- INTVCC pin for control of gate driver voltage
- Programmable soft start
- Programmable undervoltage lockout
- Isolated telecom converters
- High power automotive supplies
- Isolated industrial power supplies