LT3748IMS#TRPBF

Overview

The LT3748IMS#TRPBF is a switching regulator controller designed for isolated flyback topologies, operating within an input voltage range of 5 V to 100 V. It utilizes boundary mode control and primary-side regulation, eliminating the need for opto-isolators or tertiary windings by sensing output voltage directly from the flyback waveform. The device drives an external low-side N-channel MOSFET using an internally regulated 7 V supply. Key electrical parameters include a quiescent current of 1.3 mA, a switching frequency of 42 kHz, and an adjustable output configuration. It supports load currents up to 1.9 A and functions across an extended temperature range from -40°C to +125°C.

Feature Summary

• Enables primary-side regulation by sensing isolated output voltage directly from the primary flyback waveform, removing the requirement for opto-isolators or auxiliary windings.
• Operates in boundary mode to optimize magnetic component size while maintaining effective load regulation capabilities.
• Integrates an internally regulated 7 V supply to drive external low-side N-channel power MOSFETs.
• Supports high-power applications with input voltages up to 100 V and adjustable output configurations.

Applications

• Isolated DC-DC converter designs requiring simplified transformer structures
• High-voltage input power supplies up to 100 V
• Applications prioritizing reduced bill-of-materials by eliminating opto-isolation components

Procurement Notes

Verify the specific suffix #TRPBF confirms tape-and-reel packaging when required for automated assembly processes. Confirm that the IMS designation corresponds to the MSOP-16 package variant suitable for surface-mount installation. Ensure compatibility with the intended thermal management strategy, as the device operates within a specified industrial temperature range. Cross-reference the manufacturer's latest documentation for any updates regarding lead-free compliance and environmental declarations prior to final procurement authorization.

Selection Notes

Select this controller for flyback applications where primary-side regulation simplifies the design by removing opto-isolators. It is suitable for systems requiring input voltages up to 100 V and benefits from boundary mode operation for efficient magnetic design. Consider the MSOP-16 package constraints for thermal dissipation and board space. Verify that the external MOSFET selection aligns with the internal 7 V gate drive capability and the target power levels.

Part Context

The LT3748 is part of Analog Devices' portfolio of switching regulator controllers specialized for isolated flyback topologies. This series focuses on reducing component count and complexity through primary-side regulation techniques. The IMS#TRPBF variant specifically denotes the industrial temperature grade version packaged in a 16-lead MSOP format and supplied in tape-and-reel form for manufacturing efficiency.

Replacement Considerations

Direct substitutes within the same family include LT3748EMS#TRPBF and LT3748HMS#TRPBF, which share identical functional specifications but differ in temperature grades and packaging formats. Verify that alternative packages match the PCB footprint requirements before substitution.