
Linear Technology
DESCRIPTION
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).
FEATURES
■ Full Featured Li-Ion/Polymer Charger/PowerPath™
Controller with Instant-On Operation
■ Triple Adjustable High Effi ciency 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
APPLICATIONS
■ PNDs, DMB/DVB-H, Digital/Satellite Radio, Media Players
■ Portable Industrial/Medical Products
■ Other USB-Based Handheld Products