LTC3553 - Micropower USB Power Manager With Li-Ion Charger, LDO and Buck Regulator


  • 12μA Standby Mode Quiescent Current (All Outputs On)
  • Seamless Transition Between Input Power Sources: Li-Ion/Polymer Battery and USB
  • 240mΩ Internal Ideal Diode Provides Low Loss PowerPath™
  • High Efficiency 200mA Buck Regulator
  • 150mA Low Dropout (LDO) Linear Regulator
  • Pushbutton On/Off Control With System Reset
  • Full Featured Li-Ion/Polymer Battery Charger
  • Programmable Charge Current With Thermal Limiting
  • Instant-On Operation With Discharged Battery
  • 3mm × 3mm × 0.75mm 20-Pin QFN Package

Typical Application

LTC3553 Typical Application
LTC3553 Typical Application


The LTC®3553 is a micropower, highly integrated power management and battery charger IC for single-cell Li-Ion/Polymer battery applications. It includes a PowerPath manager with automatic load prioritization, a battery charger, an ideal diode and numerous internal protection features. Designed specifically for USB applications, the LTC3553 power manager automatically limits input current to a maximum of either 100mA or 500mA. Battery charge current is automatically reduced such that the sum of the load current and the charge current does not exceed the selected input current limit. The LTC3553 also includes a synchronous buck regulator, a low dropout linear regulator (LDO), and a pushbutton controller. With all supplies enabled in standby mode, the quiescent current drawn from the battery is only 12μA. The LTC3553 is available in a 3mm × 3mm × 0.75mm 20-pin QFN package.

OptionsLDOPGOODHard Reset Time
LTC3553 ON/OFF Control No 5 seconds
LTC3553-2 Always On Yes 14 seconds


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
LTC3553EUD#PBF 3x3 QFN-20 UD E 05-08-1720 Yes
LTC3553EUD#TRPBF 3x3 QFN-20 UD E 05-08-1720 Yes

LTC3553 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
LTC3553EUD#PBF 3x3 QFN-20 E $3.22 $2.25 Yes
LTC3553EUD#TRPBF 3x3 QFN-20 E $2.31 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
DC1550A LTC3553EPD Demo Board | Micropower USB Power Manager with Li-Ion Charger, LDO, and Buck Regulator $150.00
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Click here to view our complete list of demo boards


  • USB-Based Handheld Products
  • Portable Li-Ion/Polymer Based Electronic Devices
  • Wearable Electronics
  • Low Power Medical Devices

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Design Tools

Linear Technology provides a variety of custom design simulation tools and device models to allow even novice designers to quickly and easily evaluate circuits using high performance switching regulators, amplifiers, data converters, filters and more. Please visit our Design Tools page to view and download:

  • LTspice - A powerful SPICE simulator, schematic capture and waveform viewer with enhancements and models for easing the simulation of switching regulators
  • LTpowerCAD - A complete power supply selection, synthesis and design tool
  • LTpowerPlay - A development environment supporting Linear Technology's Digital Power System Management (PSM) products
  • PScope & QuikEval - USB-based product demonstration and data acquisition system for use with our ADCs, DACs, and more
  • Linduino - Arduino compatible system for developing and distributing firmware libraries and example code
  • LinearLab Tools - A collection of Matlab and Python programs that provide direct access to Linear Technology’s data converter evaluation boards
  • And More!

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