LTC3309A

RECOMMENDED FOR NEW DESIGNS

LTC3309A

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

RECOMMENDED FOR NEW DESIGNS

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Part Models 22

1ku List Price Starting From $2.24

Features

Pin Compatible with LTC3307(3A) and LTC3308(4A)
High Efficiency: 8mΩ NMOS, 31mΩ PMOS
Programmable Frequency 1MHz to 3MHz
- 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 I_Q 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

Additional Details

The LTC3309A is a very small, high efficiency, low noise, monolithic synchronous 6A step-down DC/DC converter operating from a 2.25V to 5.5V input supply. Using constant frequency, peak current mode control at switching frequencies 1MHz to 3MHz and minimum on-time as low as 22ns, this regulator achieves fast transient response with small external components. Silent Switcher architecture minimizes EMI emissions.

The LTC3309A operates in forced continuous or pulse skip mode for low noise, or the low-ripple Burst Mode operation for high efficiency at light loads, ideal for battery-powered systems. The IC regulates output voltages as low as 500mV. Other features include output overvoltage protection, short-circuit protection, thermal shutdown, clock synchronization, and up to 100% duty cycle operation for low dropout. The device is available in a low profile 12-lead 2mm × 2mm × 0.74mm LQFN package with exposed pad for low thermal resistance.

For applications that require a faster power on, the LTC3309A-7 has a reduced power on and soft-start time.

APPLICATIONS

Optical Networking, Servers, Telecom
Automotive, Industrial, Communications
Distributed DC Power Systems (POL)
FPGA, ASIC, µP Core Supplies
Battery Operated Systems

View All Documentation

Ask a Question

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Support

Analog Devices Support Portal is a one-stop shop to answer all your ADI questions.

Visit the ADI Support Page

Ask the ADI community for help.

Ask the EngineerZone Community

FAQs

Sales & Ordering FAQs

Part Models 22

1ku List Price Starting From $2.24

Documentation

Technical Documents 2

LTC3309A: 5V, 6A Synchronous Step-Down Silent Switcher in 2mm x 2mm LQFN Data Sheet (Rev.B) 04/19/2019

R523 Reliability Data 03/24/2021

Reference Materials 4

Understanding Silent Switcher Technology: High Efficiency, Low EMI eBook 07/14/2023

Silent Switcher Technology 08/15/2023

High Power Density in a Small Form Factor 10/01/2019

Improving Switch-Mode Power Supplies Using Noise Cancelling Technology 03/17/2023

Design Resources 22

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
LTC3309AEV#TRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AEV#TRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AEV#WTRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AEV#WTRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AHV#TRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AHV#TRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AHV#WTRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AHV#WTRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AIV#TRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AIV#TRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AIV#WTRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AIV#WTRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AJV#TRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AJV#TRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AJV#WTRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AJV#WTRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AJV-7#TRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AJV-7#TRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AJV-7#WTRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AJV-7#WTRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AMPV#TRMPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys
LTC3309AMPV#TRPBF	12-Lead LQFN (2mm x 2mm x 0.74mm)	HTML Material Declaration HTML Reliablity Data	Ultra Librarian SamacSys

LTC3309AEV#TRMPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AEV#TRPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AEV#WTRMPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AEV#WTRPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AHV#TRMPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AHV#TRPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AHV#WTRMPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AHV#WTRPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AIV#TRMPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AIV#TRPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AIV#WTRMPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AIV#WTRPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AJV#TRMPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AJV#TRPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AJV#WTRMPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AJV#WTRPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AJV-7#TRMPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AJV-7#TRPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AJV-7#WTRMPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AJV-7#WTRPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AMPV#TRMPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

LTC3309AMPV#TRPBF
Pin/Package Drawing
12-Lead LQFN (2mm x 2mm x 0.74mm)
Documentation

HTML Material Declaration

HTML Reliablity Data

CAD Symbols, Footprints, and 3D Models
Ultra Librarian
SamacSys

Software & Part Ecosystem

Evaluation Kit

DC2745A

LTC3309A | 5V, 6A Synchronous Step-Down Silent Switcher in 2mm × 2mm LQFN

DC2745A

LTC3309A | 5V, 6A Synchronous Step-Down Silent Switcher in 2mm × 2mm LQFN

Buy Now View Details

Product Detail

Demonstration Circuit 2745A features the LTC3309A 5V, 6A synchronous step-down silent switcher operating as a 2MHz 3.3V to 1.2V 6A buck regulator. The LTC3309A supports adjustable output voltages from 0.5V to V_IN, operating frequencies from 1MHz up to 3MHz. The LTC3309A is a compact, ultralow emission, high efficiency, and high speed synchronous monolithic step-down switching regulator. Fast minimum on-time of 22ns enables high V_IN to low V_OUT conversion at high frequency.

DC2745A 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 LTC3309A to sync to a clock frequency from 1MHz to 3MHz. The LTC3309A operates in forced continuous mode when syncing to an external clock. RT is connected to VIN through a 0Ω resistor, R9, which sets the operating frequency to 2MHz. 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 LTC3309A data sheet for the proper RT value.

The DC2745A also has an EMI filter to reduce conducted EMI. This EMI filter can be included by applying the input voltage at the VIN EMI terminal. The EMI performance of the board is shown in the EMI Test Results section. The red lines in the EMI performance graphs illustrate the CISPR25 Class 5 peak limits for the conducted and radiated emission tests.

The LTC3309A data sheet gives a complete description of the part, operation and application information. The data sheet must be read in conjunction with this demo. The LTC3309A is assembled in a 3mm × 3mm 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.

The Efficiency vs Load graph shows the efficiency and the power loss of the circuit with a 3.3V input in Burst Mode operation. The LTC3309A is available in a 12-lead 2mm × 2mm LGA package.

Resources

PDF

DC2745A - Schematic

111.46 K

ZIP

DC2745A - Design Files

3.55 M

PDF

DC2745A - Demo Manual (Rev.0)

1.47 M

DC2745A

LTC3309A | 5V, 6A Synchronous Step-Down Silent Switcher in 2mm × 2mm LQFN

Tools & Simulations

LTspice 1

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.

To launch ready-to-run LTspice demonstration circuits for this part:

Step 1: Download and install LTspice on your computer.

Step 2: Click on the link in the section below to download a demonstration circuit.

Step 3: If LTspice does not automatically open after clicking the link below, you can instead run the simulation by right clicking on the link and selecting “Save Target As.” After saving the file to your computer, start LTspice and open the demonstration circuit by selecting ‘Open’ from the ‘File’ menu.

Lt Spice

LTC3309A - Switching Regulators

1.87 K

LTpowerCAD 1

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.

To open the project file for this circuit:

Step 1: Download and install LTpowerCAD on your computer.

Step 2: Click on the link(s) in the section below to download part-specific project files.

Step 3: If the project file doesn't run, right-click the link and select "Save Target As." Then start the LTpowerCAD tool and open the project file by selecing "Open Project" from the "File" menu.

LTpowerCAD download and documentation

Simulation Model

LTpowerCAD

LTC3309A Project - DC2745A 3-5Vin to 1.2V/6A, 2MHz

Reference Designs

Artix US+ Rail Consolidation – Minimum Rails (AU10P/15P) Power Tree

artix-ultrascale

Minimum Rails for AU10/15P and AU20/25P - Non-Hardware Verified Design

Artix US+ Rail Consolidation - Minimum Rails (AU20P/25P) Power Tree

Minimum Rails for AU10/15P and AU20/25P - Non-Hardware Verified Design

Download

artix-ultrascale

Circuits from the lab

Minimum Rails for AU10/15P and AU20/25P - Non-Hardware Verified Design

Features and Benefits

Xilinx Artix^® UltraScale+^™ devices are the industry’s only cost-optimized FPGAs based on an advanced, production-proven 16nm architecture for best-in-class performance/watt.

Analog Devices, Inc. supports power delivery solutions for the Artix Ultrascale+ low-cost designs. Monolithic solutions are used to power Xilinx FPGA and/or SoC rails as well as other system rails. These regulators are highly integrated discrete solutions optimized for cost, efficiency and footprint.

ADI provides supporting documentation including power schematics, layout, LTpowerPlanner^® and applicable LTpowerPlay^® configuration files to enable you to validate the power solution for your application seamlessly.