LT8613 - 42V, 6A Synchronous Step-Down Regulator with Current Sense and 3μA Quiescent Current

Features

  • Rail-to-Rail Current Sense Amplifier with Monitor
  • Wide Input Voltage Range: 3.4V to 42V
  • Ultralow Quiescent Current Burst Mode® Operation:
    3μA IQ Regulating 12VIN to 3.3VOUT
    Output Ripple <10mVP-P
  • High Efficiency Synchronous Operation:
    95% Efficiency at 3A, 5VOUT from 12VIN
    94% Efficiency at 3A, 3.3VOUT from 12VIN
  • Fast Minimum Switch-On Time: 40ns
  • Low Dropout Under All Conditions: 250mV at 3A
  • Allows Use Of Small Inductors
  • Low EMI
  • Adjustable and Synchronizable: 200kHz to 2.2MHz
  • Current Mode Operation
  • Accurate 1V Enable Pin Threshold
  • Internal Compensation
  • Output Soft-Start and Tracking
  • Small Thermally Enhanced 3mm × 6mm 28-Lead QFN Package
Designed for Automotive and Transportation Applications
AEC-Q100 generic family data available for specific packages


Typical Application

LT8613 Typical Application
LT8613 Typical Application

Description

The LT®8613 is a compact, high efficiency, high speed synchronous monolithic step-down switching regulator that consumes only 3μA of quiescent current. Top and bottom power switches are included with all necessary circuitry to minimize the need for external components. The built-in current sense amplifier with monitor and control pins allows accurate input or output current regulation and limiting. Low ripple Burst Mode operation enables high efficiency down to very low output currents while keeping the output ripple below 10mVP-P. A SYNC pin allows synchronization to an external clock. Internal compensation with peak current mode topology allows the use of small inductors and results in fast transient response and good loop stability. The EN/UV pin has an accurate 1V threshold and can be used to program VIN undervoltage lockout or to shut down the LT8613 reducing the input supply current to 1μA. A capacitor on the TR/SS pin programs the output voltage ramp rate during start-up. The PG flag signals when VOUT is within ±9% of the programmed output voltage as well as fault conditions. The LT8613 is available in a small 28-lead 3mm × 6mm QFN package with exposed pad for low thermal resistance.

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
LT8613EUDE#PBF 3x6 QFN-28 UDE E 05-08-1926 Yes
LT8613EUDE#TRPBF 3x6 QFN-28 UDE E 05-08-1926 Yes
LT8613IUDE#PBF 3x6 QFN-28 UDE I 05-08-1926 Yes
LT8613IUDE#TRPBF 3x6 QFN-28 UDE I 05-08-1926 Yes


LT8613 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
LT8613EUDE#PBF 3x6 QFN-28 E $7.43 $5.20 Yes
LT8613EUDE#TRPBF 3x6 QFN-28 E $5.26 Yes
LT8613IUDE#PBF 3x6 QFN-28 I $8.17 $5.72 Yes
LT8613IUDE#TRPBF 3x6 QFN-28 I $5.78 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
DC2011A LT8613EUDE Demo Board | Sync Buck, 5.8V ≤ VIN ≤ 42V, Vout = 5V @ 6A $175.00
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
LT8613IUDE#PBF 3x6 QFN-28 I $8.17 $5.72 Yes
LT8613IUDE#TRPBF 3x6 QFN-28 I $5.78 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

  • Automotive and Industrial Supplies
  • General Purpose Step-Down
  • CCCV Power Supplies

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:
LT8613

Technical Support