LT8643S-2

RECOMMENDED FOR NEW DESIGNS

42V, 6A Synchronous Step-Down Silent Switcher with 2.5µA Quiescent Current with External Compensation

Data Sheet (Rev. D) Product Selection Table

Part Models: 10
1ku List Price: Starting From $5.48

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Overview

Silent Switcher^®Architecture
- Ultralow EMI Emissions
- Optional Spread Spectrum Modulation
High Efficiency at High Frequency
- Up to 96% Efficiency at 1MHz, 12V_IN to 5V_OUT
- Up to 95% Efficiency at 2MHz, 12V_IN to 5V_OUT
Wide Input Voltage Range: 3.4V to 42V
6A Maximum Continuous, 7A Peak Output
External Compensation: Fast Transient Response and Current Sharing (LT8643S-2)
Fast Minimum Switch On-Time: 30ns

Ultralow Quiescent Current Burst Mode^® Operation
- 2.5μA I_Q Regulating 12V_IN to 3.3V_OUT (LT8640S-2)
- Output Ripple < 10mV_P-P
Low Dropout Under All Conditions: 100mV at 1A
Forced Continuous Mode
Adjustable and Synchronizable: 200kHz to 3MHz
Output Soft-Start and Tracking
Small 24-Lead 4mm × 4mm LQFN Package
AEC-Q100 Qualified for Automotive Applications

The LT8640S-2/LT8643S-2 synchronous step-down regulator features Silent Switcher architecture designed to minimize EMI emissions while delivering high efficiency at high switching frequencies. Peak current mode control with a 30ns minimum on-time allows high step-down ratios even at high switching frequencies. The LT8643S-2 has external compensation to enable current sharing and fast transient response at high switching frequencies.

Burst Mode operation enables ultralow standby current consumption, forced continuous mode can control frequency harmonics across the entire output load range, or spread spectrum operation can further reduce EMI emissions.

APPLICATIONS

Automotive and Industrial Supplies
General Purpose Step-Down

Part Models: 10
1ku List Price: Starting From $5.48

Documentation

Data Sheet 1

LT8640S-2/LT8643S-2: 42V, 6A Synchronous Step-Down Silent Switcher with 2.5μA Quiescent Current Data Sheet (Rev.D) 09/06/2023

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal. View our quality and reliability program and certifications for more information.

Part Model	Pin/Package Drawing	Documentation	CAD Symbols, Footprints, and 3D Models
LT8643SEV-2#PBF	24-Lead LQFN (4mm x 4mm x 0.94mm w/ EP)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT8643SEV-2#TRPBF	24-Lead LQFN (4mm x 4mm x 0.94mm w/ EP)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT8643SHV-2#PBF	24-Lead LQFN (4mm x 4mm x 0.94mm w/ EP)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT8643SHV-2#TRPBF	24-Lead LQFN (4mm x 4mm x 0.94mm w/ EP)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT8643SHV-2#WPBF	24-Lead LQFN (4mm x 4mm x 0.94mm w/ EP)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT8643SHV-2#WTRPBF	24-Lead LQFN (4mm x 4mm x 0.94mm w/ EP)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT8643SIV-2#PBF	24-Lead LQFN (4mm x 4mm x 0.94mm w/ EP)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT8643SIV-2#TRPBF	24-Lead LQFN (4mm x 4mm x 0.94mm w/ EP)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT8643SIV-2#WPBF	24-Lead LQFN (4mm x 4mm x 0.94mm w/ EP)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys
LT8643SIV-2#WTRPBF	24-Lead LQFN (4mm x 4mm x 0.94mm w/ EP)	Material Declaration Reliablity Data Package Resources	Ultra Librarian SamacSys

Part Models	Product Lifecycle	PCN

Sep 15, 2023 - 23_0182 Notification of Qualification of Pillar Size Update for LT3977, LT3978, LT8636, LT8637, LT8640S, LT8640S-2, LT8643S, LT8643S-2
		PCN23_0182_Form Material_Report Qualification Results Summary Delta Qualification Matrix
LT8643SEV-2#PBF	PRODUCTION
LT8643SEV-2#TRPBF	PRODUCTION
LT8643SHV-2#PBF	PRODUCTION
LT8643SHV-2#TRPBF	PRODUCTION
LT8643SHV-2#WPBF	PRODUCTION
LT8643SHV-2#WTRPBF	PRODUCTION
LT8643SIV-2#PBF	PRODUCTION
LT8643SIV-2#TRPBF	PRODUCTION
LT8643SIV-2#WPBF	PRODUCTION
LT8643SIV-2#WTRPBF	PRODUCTION
Apr 11, 2019 - 19_0067 Notification of Wafer Fab Location Change for 0.35 BCD Process
		PCN19_0067_Form Material_Report Delta Qualification Matrix Qualification Results Summary Detailed Parts List Other
LT8643SEV-2#PBF	PRODUCTION
LT8643SHV-2#PBF	PRODUCTION
LT8643SIV-2#PBF	PRODUCTION

This is the most up-to-date revision of the Data Sheet.

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Tools & Simulations

LTpowerCAD

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LT8643SA

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