LTC3309B

RECOMMENDED FOR NEW DESIGNS

5V, 6A, 10 MHz Synchronous Step-Down Silent Switcher in 2mm × 2mm LQFN

Data Sheet (Rev. 0) Product Selection Table

Part Models: 18
1ku List Price: Starting From $2.24

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Part Details

Pin Compatible with LTC3307(3A) and LTC3308(4A)
High Efficiency: 8mΩ NMOS, 31mΩ PMOS
Programmable Frequency 3MHz-10MHz

Tiny Inductor and Capacitors

Peak Current Mode Control

22ns Minimum On-Time
Wide Bandwidth, Fast Transient Response

Silent Switcher^™ Architecture

Ultralow EMI Emissions

Low Ripple Burst Mode^® Operation with IQ of 40μA

Safely Tolerates Inductor Saturation in Overload

V_IN Range: 2.25V to 5.5V

V_OUT Range: 0.5V to V_IN

V_OUT Accuracy: ±1% Over Temperature Range

Precision 400mV Enable Threshold, 1μA in Shutdown

Power Good, Internal Compensation and Soft Start

Thermally Enhanced 2mm × 2mm LQFN Package

AEC-Q100 Qualified for Automotive Applications

Part Models: 18
1ku List Price: Starting From $2.24

Documentation

Data Sheet 1

LTC3309B: 5V, 6A Synchronous Step-Down Silent Switcher in 2mm × 2mm LQFN Data Sheet (Rev.0) 10/27/2020

Reliability Data 1

R523 Reliability Data 03/24/2021

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
LTC3309BEV#TRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3309BEV#TRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3309BEV#WTRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3309BEV#WTRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3309BHV#TRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3309BHV#TRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3309BHV#WTRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3309BHV#WTRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3309BIV#TRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3309BIV#TRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3309BIV#WTRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3309BIV#WTRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3309BJV#TRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3309BJV#TRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3309BJV#WTRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3309BJV#WTRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3309BMPV#TRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	Material Declaration Reliablity Data	Ultra Librarian SamacSys
LTC3309BMPV#TRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	Material Declaration Reliablity Data	Ultra Librarian SamacSys

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

Tools & Simulations

LTspice 1

LTC3309B - Step-Down (Buck) Regulators

Models for the following parts are available in LTspice:

LTC3309A
LTC3309B

LTpowerCAD 1

LTC3309B Project - DC3054A-C 3.3Vin to 1.8Vout, 6A, 6.6MHz

LTspice® is a powerful, fast and free simulation software, schematic capture and waveform viewer with enhancements and models for improving the simulation of analog circuits.

LTpowerCAD^® is a power supply design program which selects power stage components, provides detailed power efficiency, shows quick loop Bode plot stability and load transient analysis, and can export to LTspice for simulation.

Evaluation Kits

LTC3309B | 3.3V to 1.8V at 6A, 6.6MHz Low EMI Buck Regulator in a 0.47cm2 Solution

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Features and Benefits

Demonstration circuit 3054A-C features the LTC3309B 5V, 6A synchronous step-down Silent Switcher^® operating as a 6.6MHz, 3.3V to 1.8V 6A buck regulator. The LTC3309B supports adjustable output voltages from 0.5V to V_IN, and operating frequencies from 3MHz up to 10MHz. The LTC3309B is a compact, ultralow emission, high efficiency, and high speed synchronous monolithic step-down switching regulator. A minimum on-time of 22ns enables high V_IN to low V_OUT conversion ratios at high switching frequencies.

The DC3054A-C operating mode may be selected as Burst Mode^® operation, skip or forced continuous (FC) mode. Setting JP1 to the FC/SYNC position will allow the LTC3309B to sync to a clock frequency from 3MHz to 10MHz. The LTC3309B operates in forced continuous mode when syncing to an external clock. The DC3054A-C is set to a fixed 6.6MHz.

The DC3054A-C is set to a fixed 6.6MHz frequency by connecting RT to V_IN through a 0Ω resistor, R9. The frequency can be easily changed by removing R9 and setting an appropriate resistor in the R4 location to obtain the desired frequency. Refer to the LTC3309B data sheet for the proper R_T value for a desired switching frequency.

The LTC3309B data sheet gives a complete description of the device, operation and application information. The data sheet must be read in conjunction with this demo manual. The LTC3309B is assembled in a 2mm × 2mm LQFN package with exposed pads for low thermal resistance. The layout recommendations for low EMI operation and maximum thermal performance are available in the data sheet section Low EMI PCB Layout.