LTC3566 - High Efficiency USB Power Manager Plus 1A Buck-Boost Converter


  •  High Efficiency Switching PowerPath™ Controller with Bat-Track™ Adaptive Output Control
  •  Programmable USB or Wall Input Current Limit (100mA/500mA/1A)
  •  Full Featured Li-Ion/Polymer Battery Charger
  •  “Instant-On” Operation with Discharged Battery
  •  1.5A Maximum Charge Current
  •  Internal 180mΩ Ideal Diode Plus External Ideal Diode Controller Powers Load in Battery Mode
  •  Low No-Load IQ when Powered from BAT (<30μA)
  • High Efficiency (1A IOUT)
  • 2.25MHz Constant Frequency Operation
  • Low No-Load Quiescent Current (~13μA)
  • Zero Shutdown Current
  • Pin Control of All Functions

Typical Application

LTC3566 Typical Application
LTC3566 Typical Application


The LTC3566 family are highly integrated power management and battery charger ICs for Li-Ion/Polymer battery applications. They include a high efficiency current limited switching PowerPath manager with automatic load prioritization, a battery charger, an ideal diode, and a high efficiency synchronous buck-boost switching regulator. Designed specifically for USB applications, the LTC3566 family’s switching power manager automatically limits input current to a maximum of either 100mA or 500mA for USB applications or 1A for adapter-powered applications.

The LTC3566 family’s switching input stage transmits nearly all of the 2.5W available from the USB port to the system load with minimal power wasted as heat. This feature allows the LTC3566 family to provide more power to the application and eases the constraint of thermal budgeting in small spaces. The LTC3566-2 automatically reduces charge current to maintain a regulated 3.6V VOUT during low battery conditions; the LTC3566 does not. The synchronous buck-boost DC/DC can provide up to 1A.

The LTC3566 family is available in a low profile 24-lead 4mm × 4mm QFN surface mount 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
LTC3566EUF-2#PBF 4x4 QFN-24 UF E 05-08-1697 Yes
LTC3566EUF-2#TRPBF 4x4 QFN-24 UF E 05-08-1697 Yes
LTC3566EUF#PBF 4x4 QFN-24 UF E 05-08-1697 Yes
LTC3566EUF#TRPBF 4x4 QFN-24 UF E 05-08-1697 Yes

LTC3566 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
LTC3566EUF-2#PBF 4x4 QFN-24 E $5.50 $3.85 Yes
LTC3566EUF-2#TRPBF 4x4 QFN-24 E $3.91 Yes
LTC3566EUF#PBF 4x4 QFN-24 E $5.50 $3.85 Yes
LTC3566EUF#TRPBF 4x4 QFN-24 E $3.91 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
DC1132A LTC3566 | High Effiency USB Pwr Mgr+ 1A Buck/Boost $150.00
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Click here to view our complete list of demo boards


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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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