LTC3612 - 3A, 4MHz Monolithic Synchronous Step-Down DC/DC Converter


  • 3A Output Current
  • 2.25V to 5.5V Input Voltage Range
  • Low Output Ripple Burst Mode® Operation: IQ = 70μA
  • ±1% Output Voltage Accuracy
  • Output Voltage Down to 0.6V
  • High Efficiency: Up to 95%
  • Low Dropout Operation: 100% Duty Cycle
  • Shutdown Current: ≤1μA
  • Adjustable Switching Frequency: Up to 4MHz
  • Optional Active Voltage Positioning (AVP) with Internal Compensation
  • Selectable Pulse-Skipping/Forced Continuous/Burst Mode Operation with Adjustable Burst Clamp
  • Programmable Soft-Start
  • Inputs for Start-Up Tracking or External Reference
  • DDR Memory Mode, IOUT = ±1.5A
  • Available in Thermally Enhanced 20-Pin (3mm × 4mm) QFN and TSSOP Packages

Typical Application

LTC3612 Typical Application
LTC3612 Typical Application


The LTC®3612 is a low quiescent current monolithic synchronous buck regulator using a current mode, constant frequency architecture. The no-load DC supply current in sleep mode is only 70μA while maintaining the output voltage (Burst Mode operation) at no load, dropping to zero current in shutdown. The 2.25V to 5.5V input supply voltage range makes the LTC3612 ideally suited for single Li-Ion as well as fixed low voltage input applications. 100% duty cycle capability provides low dropout operation, extending the operating time in battery-powered systems.

The operating frequency is externally programmable up to 4MHz, allowing the use of small surface mount inductors. For switching noise-sensitive applications, the LTC3612 can be synchronized to an external clock at up to 4MHz.

Forced continuous mode operation in the LTC3612 reduces noise and RF interference. Adjustable compensation allows the transient response to be optimized over a wide range of loads and output capacitors.

The internal synchronous switch increases efficiency and eliminates the need for an external catch diode, saving external components and board space. The LTC3612 is offered in a leadless 20-pin 3mm × 4mm QFN or a thermally enhanced 20-pin TSSOP 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
LTC3612EFE#PBF TSSOP-20 FE E 05-08-1663 (CB) Yes
LTC3612EFE#TRPBF TSSOP-20 FE E 05-08-1663 (CB) Yes
LTC3612EUDC#PBF 3x4 QFN-20 UDC E 05-08-1742 Yes
LTC3612EUDC#TRPBF 3x4 QFN-20 UDC E 05-08-1742 Yes
LTC3612HFE#PBF TSSOP-20 FE H 05-08-1663 (CB) Yes
LTC3612HFE#TRPBF TSSOP-20 FE H 05-08-1663 (CB) Yes
LTC3612HUDC#PBF 3x4 QFN-20 UDC H 05-08-1742 Yes
LTC3612HUDC#TRPBF 3x4 QFN-20 UDC H 05-08-1742 Yes
LTC3612IFE#PBF TSSOP-20 FE I 05-08-1663 (CB) Yes
LTC3612IFE#TRPBF TSSOP-20 FE I 05-08-1663 (CB) Yes
LTC3612IUDC#PBF 3x4 QFN-20 UDC I 05-08-1742 Yes
LTC3612IUDC#TRPBF 3x4 QFN-20 UDC I 05-08-1742 Yes
LTC3612MPFE#PBF TSSOP-20 FE MP 05-08-1663 (CB) Yes
LTC3612MPFE#TRPBF TSSOP-20 FE MP 05-08-1663 (CB) Yes
LTC3612MPUDC#PBF 3x4 QFN-20 UDC MP 05-08-1742 Yes
LTC3612MPUDC#TRPBF 3x4 QFN-20 UDC MP 05-08-1742 Yes

LTC3612 Package Drawing
LTC3612 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
LTC3612EFE#PBF TSSOP-20 E $4.64 $3.25 Yes
LTC3612EFE#TRPBF TSSOP-20 E $3.31 Yes
LTC3612EUDC#PBF 3x4 QFN-20 E $4.43 $3.10 Yes
LTC3612EUDC#TRPBF 3x4 QFN-20 E $3.16 Yes
LTC3612HFE#PBF TSSOP-20 H $5.93 $4.15 Yes
LTC3612HFE#TRPBF TSSOP-20 H $4.21 Yes
LTC3612HUDC#PBF 3x4 QFN-20 H $5.64 $3.95 Yes
LTC3612HUDC#TRPBF 3x4 QFN-20 H $4.01 Yes
LTC3612IFE#PBF TSSOP-20 I $5.46 $3.82 Yes
LTC3612IFE#TRPBF TSSOP-20 I $3.88 Yes
LTC3612IUDC#PBF 3x4 QFN-20 I $5.22 $3.65 Yes
LTC3612IUDC#TRPBF 3x4 QFN-20 I $3.71 Yes
LTC3612MPFE#PBF TSSOP-20 MP $14.86 $10.40 Yes
LTC3612MPFE#TRPBF TSSOP-20 MP $10.46 Yes
LTC3612MPUDC#PBF 3x4 QFN-20 MP $14.07 $9.85 Yes
LTC3612MPUDC#TRPBF 3x4 QFN-20 MP $9.91 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
DC1310A LTC3612EUDC Demo Board | 3A, 4MHz, Monolithic Synchronous Step-Down Regulator, QFN-20 Pkg $100.00
DC1574A LTC3612EFE Demo Board | 3A, 4MHz, Monolithic Synchronous Step-Down Regulator, TSSOP-16E Pkg $100.00
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Click here to view our complete list of demo boards


  • Point-of-Load Supplies
  • Distributed Power Supplies
  • Portable Computer Systems
  • DDR Memory Termination
  • Handheld Devices

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Design Tools


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