LTC3577-3 and -4 - Highly Integrated Portable Product PMIC


  • Full Featured Li-Ion/Polymer Charger/PowerPath™ Controller with Instant-On Operation
  • Triple Adjustable High Efficiency Step-Down Switching Regulators (800mA, 500mA, 500mA IOUT)
  • I2C Adjustable SW Slew Rates for EMI Reduction
  • High Temperature Battery Voltage Reduction Improves Safety and Reliability
  • Overvoltage Protection Controller for USB (VBUS)/Wall Inputs Provide Protection to 30V
  • Integrated 40V Series LED Back Light Driver with 60dB Brightness Control and Gradation via I2C
  • 1.5A Maximum Charge Current with Thermal Limiting
  • Battery Float Voltage:
    4.2V (LTC3577-3)
    4.1V (LTC3577-4)
  • Pushbutton ON/OFF Control with System Reset
  • Dual 150mA Current Limited LDOs
  • Start-Up Timing Compatible with SiRF Atlas IV Processor
  • Small 4mm × 7mm 44-Pin QFN Package

Typical Application

LTC3577-3 Typical Application
LTC3577-3 Typical Application


The LTC®3577-3/LTC3577-4 are highly integrated power management ICs for single cell Li-Ion/Polymer battery applications. It includes a PowerPath manager with automatic load prioritization, a battery charger, an ideal diode, input overvoltage protection and numerous other internal protection features. The LTC3577-3/LTC3577-4 are designed to accurately charge from current limited supplies such as USB by automatically reducing charge current such that the sum of the load current and the charge current does not exceed the programmed input current limit (100mA or 500mA modes). The LTC3577-3/LTC3577-4 reduce the battery voltage at elevated temperatures to improve safety and reliability. The three step-down switching regulators and two LDOs provide a wide range of available supplies. The LTC3577-3/LTC3577-4 also include a pushbutton input to control power sequencing and system reset. The onboard LED backlight boost circuitry can drive up to 10 series LEDs and includes versatile digital dimming via the I2C input. The LTC3577-3/LTC3577-4 are designed to support the SiRF Atlas IV processor and has pushbutton timing and sequencing different from other LTC3577 versions. The LTC3577-3/LTC3577-4 are available in a low profile 4mm × 7mm × 0.75mm 44-pin QFN 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
LTC3577EUFF-3#PBF 4x7 QFN-44 UFF E 05-08-1762 Yes
LTC3577EUFF-3#TRPBF 4x7 QFN-44 UFF E 05-08-1762 Yes
LTC3577EUFF-4#PBF 4x7 QFN-44 UFF E 05-08-1762 Yes
LTC3577EUFF-4#TRPBF 4x7 QFN-44 UFF E 05-08-1762 Yes

LTC3577-3 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
LTC3577EUFF-3#PBF 4x7 QFN-44 E $7.07 $4.95 Yes
LTC3577EUFF-3#TRPBF 4x7 QFN-44 E $5.01 Yes
LTC3577EUFF-4#PBF 4x7 QFN-44 E $7.07 $4.95 Yes
LTC3577EUFF-4#TRPBF 4x7 QFN-44 E $5.01 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
DC1592A-A LTC3577EUFF-3 Demo Board | Highly Integrated Portable Navigation PMIC $175.00
DC1592A-B LTC3577EUFF-4 Demo Board | Highly Integrated Portable Navigation PMIC $175.00
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Companion Boards

Part Number Description Price Documentation
DC590B Isolated USB Serial Controller for Linear Technology QuikEval-Compatible Demo Boards $50.00
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Click here to view our complete list of demo boards


  • PNDs, DMB/DVB-H, Digital/Satellite Radio, Media Players
  • Portable Industrial/Medical Products
  • Other USB-Based Handheld Products

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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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