LT3748HMS#TRPBF

Overview

The LT3748HMS#TRPBF is a switching regulator controller designed for isolated flyback topologies, capable of high-power applications. It operates with an input voltage range of 5V to 100V and utilizes boundary mode control to optimize magnetic component size while maintaining load regulation. The device drives an external low-side N-channel power MOSFET from an internally regulated 7V supply, eliminating the need for opto-isolators or tertiary windings by sensing output voltage directly from the primary-side flyback waveform. Packaged in a 16-lead MSOP, it supports enable and soft-start functions.

Feature Summary

• Primary-side regulation eliminates the requirement for opto-isolators or tertiary transformer windings
• Boundary mode operation enables compact magnetic solutions without compromising load regulation
• Integrated 7V internal supply drives external low-side N-channel power MOSFETs
• Supports step-up/step-down conversion with positive, isolation-capable outputs

Applications

• High-power isolated flyback power supplies
• Industrial power systems requiring 100V input capability
• Applications demanding reduced bill of materials through primary-side regulation
• Compact DC-DC converters where magnetic footprint optimization is critical

Procurement Notes

Verify that the specific suffix #TRPBF corresponds to tape and reel packaging rather than tube packaging when reviewing distributor listings. Confirm RoHS compliance status and lead-free designation as indicated by the PBF suffix in related part numbers. Ensure the ordering information matches the required package type for your assembly process, as availability may vary between tube and reel formats across different suppliers.

Selection Notes

Select this controller when designing flyback converters that require primary-side regulation to reduce cost and complexity. It is suitable for designs needing input voltages up to 100V and benefits from the simplified feedback loop architecture. Consider the thermal performance of the 16-MSOP package and ensure adequate PCB layout for the gate drive signals. Verify that the external MOSFET selection aligns with the internal 7V drive capability and the target power level.

Part Context

The LT3748 belongs to Analog Devices' family of switching regulator controllers specialized for isolated topologies. The HMS variant denotes the 16-lead MSOP package form factor. This component represents a solution for high-power flyback designs where traditional secondary-side regulation with opto-isolators is undesirable due to space or cost constraints. It complements other PMIC offerings by providing a dedicated control mechanism for boundary-mode flyback applications.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.