LT3645HMSE#TRPBF

Overview

The LT3645HMSE#TRPBF is a dual-output power management IC from Analog Devices, combining a high-efficiency synchronous buck converter with a low-noise LDO. It operates within an input voltage range of 3.6 V to 36 V and features a switching frequency of 750 kHz. The primary buck output delivers up to 500 mA at voltages from 0.8 V to 16 V, while the secondary LDO provides up to 200 mA at voltages from 0.8 V to 8 V. Packaged in a thermally enhanced 16-lead QFN (3x3 mm) for surface mount installation, it supports operation temperatures from -40°C to +125°C.

Feature Summary

• Integrates a synchronous step-down regulator and a linear regulator in a single compact package
• Provides independent control over two distinct output rails for flexible power distribution
• Features a fixed 750 kHz switching frequency to optimize external component size

Applications

• Industrial automation systems requiring isolated or non-isolated dual-rail power
• Embedded controllers needing simultaneous digital logic and analog supply generation
• Portable instrumentation powered by battery or wide-range DC sources

Procurement Notes

Verify the specific suffix TRPBF indicates tape-and-reel packaging when ordering. Confirm that the HMSE variant meets the required extended temperature specifications for your application environment. Cross-reference the datasheet pinout against your PCB layout to ensure correct thermal pad connection. Check current availability status as supply constraints may affect lead times.

Selection Notes

Select this component when space-constrained designs require both switched and linear regulation capabilities. Ensure the total load current does not exceed the combined thermal limits of the QFN package. Consider the 750 kHz frequency trade-off between efficiency and EMI if operating near sensitive RF circuits. Validate that the input voltage remains within the 3.6 V to 36 V window during all transient conditions.

Part Context

This part belongs to the LT3645 family of mixed-mode PMICs designed for high-density applications. It differs from single-output regulators by offering integrated LDO functionality alongside the main buck converter. The MSOP-16 variants in similar families offer different pinouts and thermal characteristics compared to this QFN configuration.

Replacement Considerations

LT3645EUD#PBF offers identical electrical performance but utilizes a tube-packaged QFN-16 format instead of the tape-and-reel option.