LT3748IMS#PBF

Overview

The LT3748IMS#PBF is a switching regulator controller designed for isolated flyback topologies, operating within an input voltage range of 5 V to 100 V. It features a maximum output current capability of 1.9 A and supports adjustable output configurations. The device operates with a static current of 1.3 mA and utilizes boundary mode control. It functions at a switch frequency of 42 kHz and is rated for operation between -40°C and +125°C. Packaged in a 16-lead MSOP, it drives external N-channel MOSFETs without requiring opto-isolators.

Feature Summary

• Enables regulation by sensing isolated output voltage directly from the primary-side flyback waveform, eliminating the need for opto-isolators or third windings.
• Utilizes boundary mode operation to facilitate compact magnetic solutions while maintaining load regulation performance.
• Drives low-side external N-channel power MOSFETs using an internally regulated 7V supply for high-power delivery.

Applications

• Isolated flyback power supply designs
• High-voltage DC-DC conversion systems up to 100V input
• Applications requiring simplified isolation feedback loops

Procurement Notes

Verify that the specific suffix #PBF corresponds to the tube packaging variant rather than the tape-and-reel configuration. Confirm RoHS compliance status and ensure the 16-MSOP package dimensions align with the target PCB footprint requirements before finalizing procurement orders.

Selection Notes

Select this component when designing isolated flyback converters that require high input voltage tolerance up to 100V. It is suitable for applications where minimizing component count by removing opto-isolators is a priority. Ensure the external transformer design supports boundary mode operation to achieve the specified efficiency and regulation characteristics.

Part Context

This part belongs to the LT3748 series of switching regulators manufactured by Analog Devices Inc. It is categorized under PMIC power management ICs specifically for DC-DC switching controllers. The device is distinct from non-isolated controllers due to its specialized flyback topology support and primary-side sensing capabilities.

Replacement Considerations

No public confirmed substitute part numbers are available in the provided documentation. Verify compatibility with existing transformer designs if considering alternative controllers, as primary-side regulation requires specific magnetics.

FAQ

Does the LT3748 require an opto-isolator for regulation?

No, the LT3748 senses the isolated output voltage directly from the primary-side flyback waveform, eliminating the need for an opto-isolator or third winding.

What is the maximum input voltage supported by this controller?

The LT3748 supports a maximum input voltage of 100 V.