LTC3111 - 15V, 1.5A Synchronous Buck-Boost DC/DC Converter


  • Regulated Output with VIN Above, Below or Equal to VOUT
  • 2.5V to 15V Input and Output Voltage Range
  • 1.5A Continuous Output Current: VIN ≥ 5V, VOUT = 5V, PWM Mode
  • Single Inductor
  • Accurate RUN Threshold
  • Up to 95% Efficiency
  • 800kHz Switching Frequency, Synchronizable Between 600kHz and 1.5MHz
  • 49μA No-Load Quiescent Current in Burst Mode® Operation
  • Output Disconnect in Shutdown
  • Shutdown Current < 1μA
  • Internal Soft-Start
  • Small, Thermally Enhanced 14-Lead (3mm × 4mm × 0.75mm) DFN and 16-Lead MSOP Packages

Typical Application

LTC3111 Typical Application
LTC3111 Typical Application


The LTC®3111 is a fixed frequency, synchronous buckboost DC/DC converter with an extended input and output range. The unique 4-switch, single inductor architecture provides low noise and seamless operation from input voltages above, below or equal to the output voltage.

With an input and output range of 2.5V to 15V, the LTC3111 is well suited for a wide variety of single or multiple-cell batteries, back-up capacitor or wall adapter source applications. Low RDS(ON) internal N-channel MOSFET switches and selectable PWM or Burst Mode operation produce high efficiency over a wide range of operating conditions. An accurate RUN pin allows the user to program the turn-on threshold voltage of the converter. Other features include: short-circuit protection, internal soft-start and thermal shutdown.

The LTC3111 is offered in both thermally enhanced 14-lead (3mm × 4mm × 0.75mm) DFN and 16-lead MSOP packages.


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
LTC3111EDE#PBF 4x3 DFN-14 DE E 05-08-1708 Yes
LTC3111EDE#TRPBF 4x3 DFN-14 DE E 05-08-1708 Yes
LTC3111EMSE#PBF MS-16E MSE E 05-08-1667 Yes
LTC3111EMSE#TRPBF MS-16E MSE E 05-08-1667 Yes
LTC3111HDE#PBF 4x3 DFN-14 DE H 05-08-1708 Yes
LTC3111HDE#TRPBF 4x3 DFN-14 DE H 05-08-1708 Yes
LTC3111HMSE#PBF MS-16E MSE H 05-08-1667 Yes
LTC3111HMSE#TRPBF MS-16E MSE H 05-08-1667 Yes
LTC3111IDE#PBF 4x3 DFN-14 DE I 05-08-1708 Yes
LTC3111IDE#TRPBF 4x3 DFN-14 DE I 05-08-1708 Yes
LTC3111IMSE#PBF MS-16E MSE I 05-08-1667 Yes
LTC3111IMSE#TRPBF MS-16E MSE I 05-08-1667 Yes
LTC3111MPDE#PBF 4x3 DFN-14 DE MP 05-08-1708 Yes
LTC3111MPDE#TRPBF 4x3 DFN-14 DE MP 05-08-1708 Yes
LTC3111MPMSE#PBF MS-16E MSE MP 05-08-1667 Yes
LTC3111MPMSE#TRPBF MS-16E MSE MP 05-08-1667 Yes

LTC3111 Package Drawing
LTC3111 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
LTC3111EDE#PBF 4x3 DFN-14 E $5.00 $3.50 Yes
LTC3111EDE#TRPBF 4x3 DFN-14 E $3.56 Yes
LTC3111EMSE#PBF MS-16E E $5.14 $3.60 Yes
LTC3111EMSE#TRPBF MS-16E E $3.66 Yes
LTC3111HDE#PBF 4x3 DFN-14 H $5.86 $4.10 Yes
LTC3111HDE#TRPBF 4x3 DFN-14 H $4.16 Yes
LTC3111HMSE#PBF MS-16E H $6.02 $4.21 Yes
LTC3111HMSE#TRPBF MS-16E H $4.27 Yes
LTC3111IDE#PBF 4x3 DFN-14 I $5.50 $3.85 Yes
LTC3111IDE#TRPBF 4x3 DFN-14 I $3.91 Yes
LTC3111IMSE#PBF MS-16E I $5.66 $3.96 Yes
LTC3111IMSE#TRPBF MS-16E I $4.02 Yes
LTC3111MPDE#PBF 4x3 DFN-14 MP $14.86 $10.40 Yes
LTC3111MPDE#TRPBF 4x3 DFN-14 MP $10.46 Yes
LTC3111MPMSE#PBF MS-16E MP $15.27 $10.69 Yes
LTC3111MPMSE#TRPBF MS-16E MP $10.75 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
DC1999A LTC3111 Demo Board | Buck-Boost Converter, 2.5V ≤ VIN ≤ 15V, Vout = 5V @ 1.5A $150.00
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Click here to view our complete list of demo boards


  • 3.3V or 5V from 1, 2 or 3 Li-Ion, Multiple-Cell Alkaline/NiMH Batteries
  • RF Transmitters
  • Military, Industrial Power Systems

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