LT3689HMSE#TRPBF

Overview

The LT3689HMSE#TRPBF is a high-efficiency, synchronous step-down DC/DC converter featuring an integrated 2.5A switch and a 40V input voltage range. It operates with a fixed 1.2MHz switching frequency to minimize external component size while maintaining precise output regulation. The device incorporates cycle-by-cycle current limit, thermal shutdown, and soft-start functionality for robust protection. It supports output voltages from 0.8V to 36V via an external resistor divider. The MSOP-10 package facilitates compact board layouts suitable for space-constrained portable applications.

Feature Summary

• Integrated synchronous rectification with a 2.5A power switch for high efficiency across load ranges
• Fixed 1.2MHz switching frequency reduces required inductor and capacitor values
• Wide 4.5V to 40V input voltage range accommodates various power sources
• Built-in protections including thermal shutdown, cycle-by-cycle current limiting, and soft-start

Applications

• Portable instrumentation and test equipment
• Industrial control systems with wide input voltage requirements
• Battery-powered devices requiring efficient step-down conversion
• Point-of-load regulation in communication infrastructure

Procurement Notes

Verify the specific suffix TRPBF indicates tape-and-reel packaging and lead-free compliance when ordering. Confirm the HMSE grade corresponds to the extended temperature range specifications required for your application environment. Ensure the order quantity matches the reel size specified in the manufacturer's packaging documentation to avoid partial reel handling issues.

Selection Notes

Select this component when a wide input voltage range up to 40V is required alongside moderate output current capabilities around 2.5A. The fixed 1.2MHz frequency makes it suitable for designs prioritizing small passive component sizes over ultra-low noise performance. Consider the thermal performance of the MSOP-10 package relative to your expected ambient temperatures and PCB copper area for adequate heat dissipation without additional heatsinking.

Part Context

This part belongs to Analog Devices' LT3689 family of synchronous buck converters. The family shares core architecture but varies in switch current ratings, package types, and temperature grades. The HMSE designation specifies the military/extended temperature grade variant housed in a small outline MOSFET package, distinguishing it from standard commercial grade options within the same functional series.

Replacement Considerations

Direct pin-compatible replacements may include other LT3689 variants with different suffixes indicating package or temperature changes, provided the electrical characteristics match the design requirements. Cross-referencing with similar current-rated synchronous buck converters from other manufacturers requires careful verification of pinout compatibility, switching frequency, and control loop stability.