LT8640HUDCF#PBF

Overview

The LT8640HUDCF#PBF is a synchronous step-down Silent Switcher® 2 regulator from Analog Devices, designed for high-efficiency power conversion. It accepts an input voltage range of 3.4V to 42V and delivers up to 5A of continuous output current with a peak capability of 7A. The device features a fixed 2MHz switching frequency and supports adjustable output voltages starting from 970mV. Packaged in an 18-lead QFN with exposed pad, it operates within a junction temperature range of -40°C to +150°C.

Feature Summary

• Silent Switcher 2 architecture utilizes internal input capacitors and copper pillars to minimize thermal loop area and significantly reduce EMI/EMC radiation without external shielding.
• Fixed 2MHz switching frequency enables the use of compact external components while maintaining high efficiency across the load range.
• Burst Mode operation provides ultra-low quiescent current of 2.5µA, extending battery life in always-on automotive systems.
• Integrated high-side and low-side power switches eliminate the need for external boost diodes and simplify circuit design.

Applications

• Automotive infotainment and body control modules requiring CISPR25 Class 5 compliance
• Industrial point-of-load regulation for distributed power architectures
• Battery-powered equipment utilizing always-on system topologies
• General-purpose DC/DC conversion for 12V or 24V bus systems

Procurement Notes

Verify the specific suffix 'HUDCF' against the manufacturer's official datasheet to confirm package type, temperature grade, and tape/reel specifications. Ensure compatibility with PCB footprint dimensions for the 18-lead QFN package. Cross-reference AEC-Q100 qualification status if automotive reliability is required. Confirm lead-free and RoHS compliance through the latest factory documentation.

Selection Notes

Select this component when a fixed 2MHz frequency is preferred over programmable options to optimize passive component size. Choose the HUDCF variant specifically for its extended junction temperature rating up to 150°C compared to standard industrial grades. Consider the 5A current limit for applications where peak loads do not exceed 7A. Evaluate thermal performance requirements given the dense power density of the QFN package.

Part Context

This part belongs to the LT8640 family of Silent Switcher regulators, which are engineered to address electromagnetic interference challenges in compact designs. The series integrates advanced layout techniques directly into the silicon package. The LT8640HUDCF#PBF represents the 5A current variant within this lineup, offering a balance between power density and thermal management for space-constrained environments.

Replacement Considerations

LT8640JUDCF#WTRPBF: Similar 5A Silent Switcher but may differ in packaging format (tray vs. tape) or specific thermal characteristics; verify pinout and electrical parameters.

FAQ

Does the LT8640HUDCF#PBF support frequency synchronization?

No, the LT8640H variant operates at a fixed 2MHz switching frequency and does not include pins for external synchronization, unlike other members of the LT8640 family.

What is the minimum dropout voltage of this regulator?

The device maintains a typical dropout voltage of 100mV at 1A load, allowing efficient operation even when the input voltage approaches the output voltage level.