LTC3409 - 600mA Low VIN Buck Regulator in 3mm × 3mm DFN

Features

  • 1.6V to 5.5V Input Voltage Range
  • Internal Soft-Start
  • Selectable 1.7MHz or 2.6MHz Constant Frequency Operation
  • Internal Oscillator can be Synchronizable to an External Clock, 1MHz to 3MHz Range
  • High Efficiency: Up to 95%
  • Very Low Quiescent Current: Only 65µA During Burst Mode® Operation
  • 600mA Output Current (VIN = 1.8V, VOUT = 1.2V)
  • 750mA Peak Inductor Current
  • No Schottky Diode Required
  • Low Dropout Operation: 100% Duty Cycle
  • 0.613V Reference Voltage
  • Stable with Ceramic Capacitors
  • Shutdown Mode Draws <1µA Supply Current
  • Current Mode Operation for Excellent Line and Load Transient Response
  • Overtemperature Protection
  • Available in a Low Profile (0.75mm) 8-Lead
    (3mm × 3mm) DFN Package
Designed for Automotive and Transportation Applications
AEC-Q100 generic family data available for specific packages


Typical Application

LTC3409 Typical Application
LTC3409 Typical Application

Description

The LTC3409 is a high efficiency, monolithic synchronous buck regulator using a constant frequency, current mode architecture. The output voltage is adjusted via an external resistor divider.

Fixed switching frequencies of 1.7MHz and 2.6MHz are supported. Alternatively, an internal PLL will synchronize to an external clock in the frequency range of 1MHz to 3MHz. This range of switching frequencies allows the use of small surface mount inductors and capacitors, including ceramics.

Supply current during Burst Mode operation is only 65µA dropping to <1µA in shutdown. The 1.6V to 5.5V input voltage range makes the LTC3409 ideally suited for single cell Li-Ion, Li-Metal and 2-cell alkaline, NiCd or NiMH battery-powered applications. 100% duty cycle capability provides low dropout operation, extending battery life in portable systems. Burst Mode operation can be user enabled, increasing efficiency at light loads, further extending battery life.

The internal synchronous switch increases efficiency and eliminates the need for an external Schottky diode. Internal soft-start offers controlled output voltage rise time at start-up without the need for external components.

Protected by U.S. Patents, including 5481178, 6580258, 6304066, 6127815, 6498466, 6611131.

  Vref Tolerance
LTC3409 +/-5%
LTC3409A +/-3%

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
LTC3409EDD#PBF 3x3 DFN-8 DD E 05-08-1698 Yes
LTC3409EDD#TRPBF 3x3 DFN-8 DD E 05-08-1698 Yes
LTC3409IDD#PBF 3x3 DFN-8 DD I 05-08-1698 Yes
LTC3409IDD#TRPBF 3x3 DFN-8 DD I 05-08-1698 Yes


LTC3409 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
LTC3409EDD#PBF 3x3 DFN-8 E $3.07 $2.15 Yes
LTC3409EDD#TRPBF 3x3 DFN-8 E $2.25 Yes
LTC3409IDD#PBF 3x3 DFN-8 I $3.53 $2.47 Yes
LTC3409IDD#TRPBF 3x3 DFN-8 I $2.53 Yes
Buy NowRequest Samples
* 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
DC828A LTC3409EDD Demo Board | 1.6V ≤ VIN ≤ 5.5V, Vout = 1.2V/1.5V/1.8V @ 600mA $75.00
Buy Now
Click here to view our complete list of demo boards

Designed for Automotive and Transportation Applications

Please contact your local sales representative for more information regarding reliability reports and AEC-Q100 data or to inquire about parts that are not included. For more information, view our Automotive and Transportation page

Part Number Package Temp Price
(1-99)
Price
(1k)*
RoHS
LTC3409IDD#PBF 3x3 DFN-8 I $3.53 $2.47 Yes
LTC3409IDD#TRPBF 3x3 DFN-8 I $2.53 Yes
Buy NowRequest Samples
* 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.

Applications

  • Cellular Phones
  • Digital Cameras
  • MP3 Players

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:
LTC3409

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:
LTC3409
LTC3409A

Technical Support