LT3971IDD-3.3

Overview

The LT3971IDD-3.3#PBF is a synchronous step-down switching regulator manufactured by Analog Devices Inc., housed in a 10-lead DFN package. It accepts an input voltage range of 4.3V to 38V and provides a fixed 3.3V output at up to 1.2A. The device features a programmable switching frequency adjustable from 200kHz to 2MHz, enabling optimization for efficiency or transient response. Quiescent current is specified at 2.8µA during operation and drops to 1.7µA in shutdown mode. It operates within a temperature range of -40°C to +125°C.

Feature Summary

• Synchronous buck topology with integrated high-side and low-side power switches
• Programmable switching frequency allows design flexibility between efficiency and component size
• Ultra-low quiescent current supports extended battery life in portable applications
• Integrated soft-start minimizes inrush current during startup

Applications

• Battery-powered portable equipment requiring efficient voltage regulation
• Industrial control systems operating from wide input voltage rails
• Automotive electronics compatible with 12V or 24V nominal systems
• Embedded computing platforms needing stable 3.3V logic supply

Procurement Notes

Verify the complete part number including suffixes such as #PBF for lead-free compliance and package type when ordering. Confirm availability status directly with authorized distributors as supply levels may vary. Ensure the selected variant matches the required thermal performance and pinout configuration for your specific PCB layout requirements.

Selection Notes

Select this component when a fixed 3.3V output is required from inputs up to 38V. Choose based on the need for high efficiency at light loads due to low quiescent current. Consider the DFN package for space-constrained designs. Verify that the external inductor and capacitor values support the chosen switching frequency and load current specifications.

Part Context

This device belongs to the LT3971 family of monolithic buck regulators designed for high-efficiency power conversion. It shares architectural similarities with other members like the LT3970 and LT3973 but offers distinct output current capabilities and input voltage ranges tailored for specific application needs within the broader power management portfolio.

Replacement Considerations

LT3971EMSE-3.3#PBF serves as a functional alternative in MSOP-10 packaging. LT3971IMSE-3.3#PBF offers similar electrical characteristics in a different surface-mount variant. Cross-reference datasheets to confirm pin compatibility and thermal dissipation requirements before substitution.