LTC3557/LTC3557-1 - USB Power Manager with Li-Ion Charger and Three Step-Down Regulators

Features

• Click Here for LT3557 Evaluation Kit
• Seamless Transition Between Input Power Sources: Li-Ion Battery, USB, 5V Wall Adapter or High Voltage Buck Regulator with Bat-Track
• 200mΩ Internal Ideal Diode Plus Optional External Ideal Diode Controller Provides Low Loss Power Path When Input Current is Limited or Unavailable
• Triple Adjustable High Efficiency Step-Down Switching Regulators (600mA, 400mA, 400mA I_OUT)
• Pin Selectable Burst Mode Operation
• Full Featured Li-Ion/Polymer Battery Charger
• 1.5A Maximum Charge Current with Thermal Limiting
• Battery Float Voltage:
  4.2V (LTC3557)
  4.1V (LTC3557-1)
• Low Profile 4mm x 4mm 28-Pin QFN Package

Typical Application

Description

The LTC®3557/LTC3557-1 is a 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 LTC3557/LTC3557-1 power manager automatically limits input current to a maximum of either 100mA or 500mA for USB applications or 1A for wall adapter powered applications. Battery charge current is automatically reduced such that the sum of the load current and the charge current does not exceed the programmed input current limit. The LTC3557/LTC3557-1 also includes three adjustable synchronous step-down switching regulators and a high voltage buck regulator output controller with Bat-Track that allows efficient charging from supplies as high as 38V. The LTC3557/LTC3557-1 is available in a low profile 4mm × 4mm × 0.75mm 28-pin QFN package.

Packaging

QFN-28

Order Info

• Part numbers ending in PBF are lead free. Please contact LTC marketing for information on lead based finish parts.
• 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	Pins	Temp	Price (1-99)	Price (1k)*	RoHS Data
LTC3557EUF#PBF	QFN	28	E	$5.64	$3.95	View
LTC3557EUF#TRPBF	QFN	28	E		$4.01	View
LTC3557EUF-1#PBF	QFN	28	E	$5.64	$3.95	View
LTC3557EUF-1#TRPBF	QFN	28	E		$4.01	View
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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.

Evaluation Kits

Part Number	Description	Price
DC1138A-A	LT3557EUF/-1 | USB Pwr Manager w/ Li-Ion/Polymer Charger & Three Buck Regulator	$150.00
DC1138A-B	LT3557EUF/-1 | USB Pwr Manager w/ Li-Ion/Polymer Charger & Three Buck Regulator	$150.00
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Applications

• HDD-Based MP3 Players
• PDA, PMP, PND/GPS
• USB-Based Handheld Products

Simulate

To simulate selected Linear Technology products, please download LTSpice / SwitcherCAD III. This powerful schematic capture and simulation tool includes macro models for 80% of Linear Technology's switching regulators, over 200 op amp models, as well as resistors, transistors and MOSFET models.

For other simulation tools, visit our Design Simulation and Device Models page.