LT1939IDD#PBF

Overview

The LT1939IDD#PBF is a monolithic step-down switching regulator and linear controller manufactured by Analog Devices Inc. It integrates a high-efficiency buck converter with an adjustable output voltage range from 800 mV to 24.25 V, capable of delivering up to 2 A of output current. The device operates with an input voltage range of 3 V to 25 V and features a switchable frequency between 250 kHz and 2.2 MHz. It includes a secondary linear regulator output and supports shutdown functionality. Packaged in a DFN-12 surface-mount format, it functions within a temperature range of -40°C to +125°C.

Feature Summary

• Integrates a synchronous buck switching regulator with a dedicated linear regulator and control circuitry on a single chip
• Provides dual output capability combining high-current switching regulation with precision linear regulation
• Features adjustable switching frequency allowing optimization for efficiency or external component size
• Includes integrated shutdown control for power management and system standby applications

Applications

• Portable battery-powered equipment requiring efficient voltage conversion
• Systems needing combined switching and linear regulation outputs
• Industrial control modules operating across wide temperature ranges
• Embedded power distribution networks requiring compact footprint solutions

Procurement Notes

Verify the specific suffix designation against official Analog Devices documentation to confirm package type and temperature grade. Ensure compatibility with required input voltage levels and thermal dissipation requirements for the DFN-12 package. Cross-reference pinout configurations with target PCB layout specifications to prevent interface mismatches during integration.

Selection Notes

Evaluate the trade-off between switching frequency selection and passive component sizing based on application constraints. Consider the total output current capability when designing for peak load conditions. Assess thermal performance requirements given the power dissipation characteristics inherent to the buck topology. Verify that the input voltage range aligns with the available supply rails in the target system architecture.

Part Context

This component belongs to the LT1939 series of mixed-signal power management ICs designed for high-efficiency applications. It combines traditional switching regulator technology with linear regulation capabilities to serve complex power distribution needs. The series targets designers seeking compact solutions for multi-rail systems without sacrificing efficiency or regulation accuracy.

Replacement Considerations

Consult official Analog Devices substitution guides for verified alternative part numbers. Confirm electrical parameter equivalence and pinout compatibility before transitioning designs.