LT3973HDD-3.3#TRPBF

Overview

The LT3973HDD-3.3#TRPBF is a monolithic buck switching regulator manufactured by Analog Devices Inc., designed for high-efficiency DC-to-DC conversion in space-constrained applications. This specific variant provides a fixed 3.3V output voltage with a maximum continuous output current of 0.75A. It operates within an input voltage range of 4.2V to 42V, accommodating wide supply variations typical in automotive and industrial environments. The device features an adjustable switching frequency ranging from 195kHz to 2.15MHz, allowing optimization for size or noise performance. It incorporates a low quiescent current of 2.5µA to minimize standby power consumption. The component is housed in a 10-lead WDFN package with an exposed pad, rated for junction temperatures up to 150°C, ensuring reliability under demanding thermal conditions.

Feature Summary

• Wide input voltage capability supporting operation from 4.2V to 42V
• Adjustable switching frequency for flexible design trade-offs
• Ultra-low quiescent current for efficient power management
• Integrated synchronous rectification for high efficiency

Applications

• Automotive electronics requiring robust voltage regulation
• Industrial control systems with wide input ranges
• Battery-powered devices needing low standby current
• General-purpose step-down power supplies

Procurement Notes

Verify the suffix #TRPBF indicates tape-and-reel packaging when ordering. Confirm the fixed 3.3V output version matches system requirements, as other output voltages are available. Ensure compatibility with the 10-WDFN package footprint during PCB layout. Check manufacturer documentation for latest lead time and availability status, as supply chain conditions may vary. Validate that the operating temperature range meets the specific application environment constraints.

Selection Notes

Choose this part when a fixed 3.3V output is required without external feedback resistors. Select based on the need for a compact solution with integrated synchronous rectifiers. Consider the adjustable frequency feature if electromagnetic interference (EMI) filtering needs optimization. Evaluate the 0.75A current limit against peak load demands. Ensure the 42V maximum input rating aligns with the highest expected line voltage transients in the target application.

Part Context

The LT3973 series represents Analog Devices' lineup of high-voltage buck regulators. The LT3973HDD-3.3#TRPBF is a specific fixed-output variant within this family. It shares core architecture with adjustable versions but simplifies design by fixing the output voltage. The HDD suffix denotes the 10-lead WDFN package type. The TRPBF suffix specifies the reel packaging format for automated assembly processes.

Replacement Considerations

Direct replacements must match the 3.3V fixed output, 0.75A current rating, and 42V input range. Verify pinout compatibility for the 10-WDFN package to avoid PCB redesign. Check if alternative parts offer similar quiescent current and switching frequency ranges. Ensure thermal performance characteristics are comparable for the same enclosure.