LTC3609 - 32V, 6A Monolithic Synchronous Step-Down DC/DC Converter

Features

  • 6A Output Current
  • Wide VIN Range = 4V to 32V (36V Maximum)
  • Internal N-Channel MOSFETs
  • True Current Mode Control
  • Optimized for High Step-Down Ratios
  • tON(MIN) ≤ 100ns
  • Extremely Fast Transient Response
  • Stable with Ceramic COUT
  • ±1% 0.6V Voltage Reference
  • Power Good Output Voltage Monitor
  • Adjustable On-Time/Switching Frequency
  • Adjustable Current Limit
  • Programmable Soft-Start
  • Output Overvoltage Protection
  • Optional Short-Circuit Shutdown Timer
  • Low Shutdown IQ: 15μA
  • Available in a 7mm × 8mm 52-Pin QFN Package

Typical Application

LTC3609 Typical Application
LTC3609 Typical Application

Description

The LTC3609 is a high efficiency, monolithic synchronous step-down DC/DC converter that can deliver up to 6A output current from a 4V to 32V (36V maximum) input supply. It uses a valley current control architecture to deliver very low duty cycle operation at high frequency with excellent transient response. The operating frequency is selected by an external resistor and is compensated for variations in VIN and VOUT.

The LTC3609 can be configured for discontinuous or forced continuous operation at light load. Forced continuous operation reduces noise and RF interference while discontinuous mode provides high efficiency by reducing switching losses at light loads.

Fault protection is provided by internal foldback current limiting, an output overvoltage comparator and an optional short-circuit shutdown timer. Soft-start capability for supply sequencing is accomplished using an external timing capacitor. The regulator current limit is user programmable. A power good output voltage monitor indicates when the output is in regulation. The LTC3609 is available in a compact 7mm × 8mm 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
LTC3609EWKG#PBF 7x8 QFN-52 WKG E 05-08-1768 Yes
LTC3609EWKG#TRPBF 7x8 QFN-52 WKG E 05-08-1768 Yes
LTC3609IWKG#PBF 7x8 QFN-52 WKG I 05-08-1768 Yes
LTC3609IWKG#TRPBF 7x8 QFN-52 WKG I 05-08-1768 Yes


LTC3609 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
LTC3609EWKG#PBF 7x8 QFN-52 E $11.07 $7.75 Yes
LTC3609EWKG#TRPBF 7x8 QFN-52 E $7.85 Yes
LTC3609IWKG#PBF 7x8 QFN-52 I $13.03 $9.12 Yes
LTC3609IWKG#TRPBF 7x8 QFN-52 I $9.22 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
DC1320A-B LTC3609EWKG Demo Board | Monolithic, 5V ≤ VIN ≤ 28V, Vout = 1.5V/1.8V/2.5V/3.3V @ 6A $125.00
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Click here to view our complete list of demo boards

Applications

  • Point of Load Regulation
  • Distributed Power Systems

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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:
LTC3609

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

Design tools for the following parts are available in LTpowerCAD:
LTC3609

Technical Support