LTC3614 - 4A, 4MHz Monolithic Synchronous Step-Down DC/DC Converter

Features

  • 4A Output Current
  • 2.25V to 5.5V Input Voltage Range
  • Low Output Ripple Burst Mode® Operation: IQ = 75μA
  • ±1% Output Voltage Accuracy
  • Output Voltage Down to 0.6V
  • High Efficiency: Up to 95%
  • Low Dropout Operation: 100% Duty Cycle
  • Programmable Slew Rate on SW Node Reduces Noise and EMI
  • Adjustable Switching Frequency: Up to 4MHz
  • Optional Active Voltage Positioning (AVP) with Internal Compensation
  • Selectable Pulse-Skipping/Forced Continuous/Burst Mode Operation with Adjustable Burst Clamp
  • Programmable Soft-Start
  • Inputs for Start-Up Tracking or External Reference
  • DDR Memory Mode, IOUT = ±3A
  • Available in a 24-Pin 3mm × 5mm QFN Thermally Enhanced Package

Typical Application

LTC3614 Typical Application
LTC3614 Typical Application

Description

The LTC®3614 is a low quiescent current monolithic synchronous buck regulator using a current mode, constant frequency architecture. The no-load DC supply current in sleep mode is only 75μA while maintaining the output voltage (Burst Mode operation) at no load, dropping to zero current in shutdown. The 2.25V to 5.5V input supply voltage range makes the LTC3614 ideally suited for single Li-Ion as well as fixed low voltage input applications. 100% duty cycle capability provides low dropout operation, extending the operating time in battery-powered systems.

The operating frequency is externally programmable up to 4MHz, allowing the use of small surface mount inductors. For switching-noise-sensitive applications, the LTC3614 can be synchronized to an external clock at up to 4MHz.

Forced continuous mode operation in the LTC3614 reduces noise and RF interference. Adjustable compensation allows the transient response to be optimized over a wide range of loads and output capacitors.

The internal synchronous switch increases efficiency and eliminates the need for an external catch diode, saving external components and board space. The LTC3614 is offered in a leadless 24-pin 3mm × 5mm thermally enhanced QFN package.

Packaging

CAD Symbols and Footprints: The downloadable Zip file below contains the schematic symbol and PCB footprints.

For complete and up to date package information and drawings, please refer to our packaging page

Part Number Package Code Temp Package
Drawing
RoHS
LTC3614EUDD#PBF 3x5 QFN-24 UDD E 05-08-1833 Yes
LTC3614EUDD#TRPBF 3x5 QFN-24 UDD E 05-08-1833 Yes
LTC3614HUDD#PBF 3x5 QFN-24 UDD H 05-08-1833 Yes
LTC3614HUDD#TRPBF 3x5 QFN-24 UDD H 05-08-1833 Yes
LTC3614IUDD#PBF 3x5 QFN-24 UDD I 05-08-1833 Yes
LTC3614IUDD#TRPBF 3x5 QFN-24 UDD I 05-08-1833 Yes
LTC3614MPUDD#PBF 3x5 QFN-24 UDD MP 05-08-1833 Yes
LTC3614MPUDD#TRPBF 3x5 QFN-24 UDD MP 05-08-1833 Yes


LTC3614 Package Drawing

Order Info

  • Part numbers ending in PBF are lead free. Solder plated terminal finish (SnPb) versions are non-standard and special terms and conditions and pricing applies if available. Please contact LTC marketing for information.
  • Part numbers containing TR or TRM are shipped in tape and reel or 500 unit mini tape and reel, respectively
  • Please refer to our general ordering information or the product datasheet for more details

Package Variations and Pricing

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC3614EUDD#PBF 3x5 QFN-24 E $4.93 $3.45 Yes
LTC3614EUDD#TRPBF 3x5 QFN-24 E $3.51 Yes
LTC3614HUDD#PBF 3x5 QFN-24 H $6.43 $4.50 Yes
LTC3614HUDD#TRPBF 3x5 QFN-24 H $4.56 Yes
LTC3614IUDD#PBF 3x5 QFN-24 I $5.80 $4.06 Yes
LTC3614IUDD#TRPBF 3x5 QFN-24 I $4.12 Yes
LTC3614MPUDD#PBF 3x5 QFN-24 MP $13.30 $9.31 Yes
LTC3614MPUDD#TRPBF 3x5 QFN-24 MP $9.37 Yes
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* The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Linear Technology sales office or authorized distributor.

Demo Boards

Linear Technology offers many demo boards free of charge to qualified customers. Contact your local sales office or distributor to inquire about a demo board. Certain demo boards are also available for sale via credit card on this website. Demo boards are for evaluation purposes only. It remains the customer’s responsibility to verify proper and reliable operation in the actual end application.

Part Number Description Price Documentation
DC1467A LTC3614EUDD Demo Board | 4A, 4MHz Monolithic Synchronous Step-Down DC/DC Converter $125.00
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Click here to view our complete list of demo boards

Applications

  • Point-of-Load Supplies
  • Distributed Power Supplies
  • Portable Computer Systems
  • DDR Memory Termination
  • Handheld Devices

Product Notifications

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Design Tools

LTspice

LTspice® software is a powerful, fast and free simulation tool, schematic capture and waveform viewer with enhancements and models for improving the simulation of switching regulators. Click here to download LTspice

To launch a ready to run LTspice demonstration circuit for this part:

  • Step 1: If you have not installed LTspice on this computer, download and install LTspice
  • Step 2: Once LTspice is installed, click on the link(s) below to launch the simulation
  • Step 3: If LTspice does not automatically open after clicking the link above, 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

To explore other ready to run LTspice demonstration circuits, please visit our Demo Circuits Collection.

Models for the following parts are available in LTspice:
LTC3614

LTpowerCAD

The LTpowerCAD design tool is a complete power supply design tool program that can significantly ease the tasks of power supply design. It guides users to a solution, selects power stage components, provides detailed power efficiency, shows quick loop bode plot stability and load transient analysis, and can export a final design to LTspice for simulation. Click here to download LTpowerCAD

To open the project file for this circuit:

  • Step 1: If you have not installed LTpowerCAD on this computer, download and install LTpowerCAD
  • Step 2: Once LTpowerCAD is installed, click on the link(s) below to open the project file
  • Step 3: If LTpowerCAD does not automatically open after clicking the link above, you can open the project file by right clicking on the link and selecting "Save Target As." After saving the file to your computer, start LTpowerCAD and open the project file by selecting 'Open Project' from the 'File' menu

Design tools for the following parts are available in LTpowerCAD:
LTC3614

Technical Support