LTC4449 - High Speed Synchronous N-Channel MOSFET Driver


  • 4V to 6.5V VCC Operating Voltage
  • 38V Maximum Input Supply Voltage
  • Adaptive Shoot-Through Protection
  • Rail-to-Rail Output Drivers
  • 3.2A Peak Pull-Up Current
  • 4.5A Peak Pull-Down Current
  • 8ns TG Rise Time Driving 3000pF Load
  • 7ns TG Fall Time Driving 3000pF Load
  • Separate Supply to Match PWM Controller
  • Drives Dual N-Channel MOSFETs
  • Undervoltage Lockout
  • Low Profile (0.75mm) 2mm × 3mm DFN Package

Typical Application

LTC4449 Typical Application
LTC4449 Typical Application


The LTC4449 is a high frequency gate driver that is designed to drive two N-Channel MOSFETs in a synchronous DC/DC converter. The powerful rail-to-rail driver capability reduces switching losses in MOSFETs with high gate capacitance.

The LTC4449 features a separate supply for the input logic to match the signal swing of the controller IC. If the input signal is not being driven, the LTC4449 activates a shutdown mode that turns off both external MOSFETs. The input logic signal is internally level-shifted to the bootstrapped supply, which functions at up to 42V above ground.

The LTC4449 contains undervoltage lockout circuits on both the driver and logic supplies that turn off the external MOSFETs when an undervoltage condition is present. An adaptive shoot-through protection feature is also built-in to prevent the power loss resulting from MOSFET cross conduction current.

The LTC4449 is available in the 2mm × 3mm DFN package.


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
LTC4449EDCB#PBF 2x3 DFN-8 DCB E 05-08-1718 Yes
LTC4449EDCB#TRMPBF 2x3 DFN-8 DCB E 05-08-1718 Yes
LTC4449EDCB#TRPBF 2x3 DFN-8 DCB E 05-08-1718 Yes
LTC4449IDCB#PBF 2x3 DFN-8 DCB I 05-08-1718 Yes
LTC4449IDCB#TRMPBF 2x3 DFN-8 DCB I 05-08-1718 Yes
LTC4449IDCB#TRPBF 2x3 DFN-8 DCB I 05-08-1718 Yes

LTC4449 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
LTC4449EDCB#PBF 2x3 DFN-8 E $1.79 Yes
LTC4449EDCB#TRMPBF 2x3 DFN-8 E $1.79 $1.30 Yes
LTC4449EDCB#TRPBF 2x3 DFN-8 E $1.79 $1.25 Yes
LTC4449IDCB#PBF 2x3 DFN-8 I $1.99 Yes
LTC4449IDCB#TRMPBF 2x3 DFN-8 I $1.99 $1.44 Yes
LTC4449IDCB#TRPBF 2x3 DFN-8 I $1.99 $1.39 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.

Click here to view our complete list of demo boards


  • Distributed Power Architectures
  • High Density Power Modules

Product Notifications

Please login to your MyLinear account for notifications of datasheet updates, new document releases and LTspice model announcements for your favorite products. If you do not have a MyLinear account you may Sign Up Now.

Forgot your password? Click here.
Need help? Email with questions and comments.

Design Tools


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:

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

Models for the following parts are available in LTspice:


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:

Technical Support