LTC3525D-3.3 - 400mA Micropower Synchronous Step-Up DC/DC Converter with Pass Through Mode


  • VOUT Connected to VIN in Shutdown
  • Up to 95% Efficiency
  • 0.85V Minimum Input Start-Up Voltage
  • Fixed Output Voltage of 3.3V
  • Delivers 60mA at 3.3V from a 1V Input, or 140mA at 3.3V from a 1.8V Input
  • Burst Mode® Operation: IQ = 7μA
  • VIN Range: 0.5V to 4.5V
  • Only Three External Components
  • VIN > VOUT Operation
  • Anti-Ringing Control
  • Short-Circuit and Overtemperature Protection
  • Very Low Profile of 1mm
  • Tiny 6-Lead SC70 Package

Typical Application

LTC3525D-3.3 Typical Application
LTC3525D-3.3 Typical Application


The LTC®3525D-3.3 is a high efficiency synchronous stepup DC/DC converter that can start up with an input as low as 0.85V. It offers a compact, high efficiency alternative to charge pumps in single cell or dual cell alkaline or Li-Ion applications. Only three small external components are required. The LTC3525D features a fixed output voltage of 3.3V. In shutdown, VOUT is connected to VIN through the inductor.

The device includes a 0.5Ω N-channel MOSFET switch and a 0.8Ω P-channel synchronous rectifier. Peak switch current ranges from 150mA to 400mA, depending on load, providing enhanced efficiency. Quiescent current is an ultralow 7μA, maximizing battery life in portable applications.

Other features include anti-ringing control and thermal shutdown. The LTC3525D is available in a tiny 6-Lead SC70 package.

List of LTC3525 Options
LTC3525-3 0.85V 3V Output Disconnect
LTC3525-3.3 0.85V 3.3V Output Disconnect
LTC3525-5 0.85V 5V Output Disconnect
LTC3525D-3.3 0.85V 3.3V Pass Through Mode
LTC3525L-3 0.7V 3V Output Disconnect


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
LTC3525DESC6-3.3#TRMPBF SC-70 SC6 E 05-08-1638 Yes
LTC3525DESC6-3.3#TRPBF SC-70 SC6 E 05-08-1638 Yes
LTC3525DISC6-3.3#PBF SC-70 SC6 I 05-08-1638 Yes
LTC3525DISC6-3.3#TRMPBF SC-70 SC6 I 05-08-1638 Yes
LTC3525DISC6-3.3#TRPBF SC-70 SC6 I 05-08-1638 Yes

LTC3525D-3.3 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
LTC3525DESC6-3.3#TRMPBF SC-70 E $2.57 $1.86 Yes
LTC3525DESC6-3.3#TRPBF SC-70 E $2.57 $1.81 Yes
LTC3525DISC6-3.3#PBF SC-70 I $2.86 Yes
LTC3525DISC6-3.3#TRMPBF SC-70 I $2.86 $2.05 Yes
LTC3525DISC6-3.3#TRPBF SC-70 I $2.86 $2.00 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
DC879A-A LTC3525-3.3 Demo Board | Micropower Synchronous Step-Up, 1V to 3.2VIN, 3.3VOUT @ 140mA $75.00
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Click here to view our complete list of demo boards


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