LT3991IDD#TRPBF

Overview

The LT3991IDD#TRPBF is a high voltage, step-down switching regulator manufactured by Analog Devices Inc. It operates from an input voltage range of 4.3V to 55V and delivers up to 1.2A of output current. The device features an adjustable output voltage ranging from 1.19V to 30V with a single positive output configuration. Switching frequency is programmable between 200kHz and 2MHz using an external resistor. The IC is housed in a compact 10-WFDFN package with exposed pad for surface mount installation. It supports operation over a junction temperature range of -40°C to 125°C.

Feature Summary

• Supports wide input voltage range up to 55V for flexible power supply integration
• Programmable switching frequency allows optimization for efficiency or component size
• Adjustable output voltage provides versatile regulation capabilities
• Compact 10-lead DFN package facilitates space-constrained board designs

Applications

• Industrial control systems requiring isolated or non-isolated power conversion
• Automotive electronics operating within standard vehicle electrical architectures
• Distributed power supplies in telecommunications infrastructure
• Battery-powered equipment requiring efficient step-down regulation

Procurement Notes

Verify the specific suffix TRPBF indicates tape and reel packaging when ordering. Confirm the IDD variant corresponds to the required temperature grade and package type. Ensure compatibility with existing PCB footprints for the 10-WFDFN package. Cross-reference the manufacturer part number with official Analog Devices documentation to avoid counterfeit components. Validate that the requested quantity matches the specified reel packaging requirements.

Selection Notes

Select this component when input voltages exceed typical 36V limits but remain below 55V. Consider the adjustable output feature if fixed voltage regulators do not meet system requirements. Evaluate the 1.2A current capability against peak load demands including transient conditions. Assess thermal performance needs based on the 10-WFDFN package's heat dissipation characteristics. Verify that the external resistor programming for frequency does not conflict with EMI constraints.

Part Context

The LT3991 belongs to Analog Devices' family of high voltage buck converters designed for demanding applications. It complements lower voltage regulators by handling higher input rails without additional pre-regulation stages. The device integrates protection features common to modern switching regulators. Its design targets industrial and automotive sectors where reliability and wide operating ranges are critical. The IDD suffix denotes a specific temperature and package variation within the broader LT3991 product line.

Replacement Considerations

LT3991IMSE-5#PBF offers similar functionality in MSOP-10 packaging with fixed 5V output.