LTC3626 - 20V, 2.5A Synchronous Monolithic Step-Down Regulator with Current and Temperature Monitoring


  • 3.6V to 20V Input Voltage Range
  • Wide Output Voltage Range of 0.6V to 97% VIN Optimized for 0.6V to 6V
  • Low RDS(ON) Integrated Switches Provide Up to 95% Efficiency
  • Up to 2.5A of Output Current
  • Average Input and Output Current Monitoring
  • Programmable Average Input/Output Current Limit
  • Die Temperature Monitor and Programmable Limit
  • Adjustable Switching Frequency: 500kHz to 3MHz
  • External Frequency Synchronization
  • Current Mode Operation for Excellent Line and Load Transient Response
  • 0.6V Reference with 1% Accuracy Over Temperature
  • User Selectable Burst Mode® or Forced Continuous Operation
  • Short-Circuit Protected
  • Output Voltage Tracking Capability
  • Power Good Status Output
  • Available in Small, Thermally Enhanced, 20-Lead (3mm × 4mm) QFN Package

Typical Application

LTC3626 Typical Application
LTC3626 Typical Application


The LTC®3626 is a high efficiency, monolithic synchronous buck regulator using a phase-lockable controlled on-time, current mode architecture capable of supplying up to 2.5A of output current. The operating supply voltage range is 3.6V to 20V, making it suitable for a wide range of power supply applications.

The operating frequency is programmable from 500kHz to 3MHz with an external resistor allowing the use of small surface mount inductors. For applications sensitive to switching noise, the LTC3626 can be externally synchronized over the same frequency range. An internal phaselocked loop aligns the on-time of the top power MOSFET to the internal or external clock. This unique controlled on-time architecture is ideal for high step-down ratio applications that demand high switching frequencies and fast transient response. An internal phase lock loop servos the on-time of the internal one-shot timer to match the frequency of the internal clock or an applied external clock.

The LTC3626 offers two operational modes: Burst Mode and forced continuous mode to allow the user to optimize output voltage ripple, noise and light load efficiency for a given application.


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
LTC3626EUDC#PBF 3x4 QFN-20 UDC E 05-08-1742 Yes
LTC3626EUDC#TRPBF 3x4 QFN-20 UDC E 05-08-1742 Yes
LTC3626IUDC#PBF 3x4 QFN-20 UDC I 05-08-1742 Yes
LTC3626IUDC#TRPBF 3x4 QFN-20 UDC I 05-08-1742 Yes

LTC3626 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
LTC3626EUDC#PBF 3x4 QFN-20 E $4.93 $3.45 Yes
LTC3626EUDC#TRPBF 3x4 QFN-20 E $3.51 Yes
LTC3626IUDC#PBF 3x4 QFN-20 I $5.67 $3.97 Yes
LTC3626IUDC#TRPBF 3x4 QFN-20 I $4.03 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
DC1768A LTC3626EUDC Demo Board I 3.6V ≤ VIN ≤20V, VOUT = 0.6V to 6V @ 2.5A, Current & Temp Monitoring $150.00
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  • Distributed Power Systems
  • Battery-Powered Instruments
  • Point-of-Load Power Supply

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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:

  • 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

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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:

  • 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:

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