Features

• High Efficiency Charger Capable of 3.5A Charge Current
• Charge Control Algorithm Specifically Designed for LiFePO₄ Batteries (Lithium Iron Phosphate)
• Monolithic Switching Regulator Makes Optimal Use of Limited Power and Thermal Budget
• Dual Input Overvoltage Protection Controller
• Priority Multiplexing for Multiple Inputs
• I²C/SMBus Control and Status Feedback
• NTC Thermistor ADC for Temperature Dependent Charge Algorithms (JEITA)
• Instant-On Operation with Low Battery
• Battery Ideal Diode Controller for Power Management
• USB On-The-Go Power Delivery to the USB Port
• Four Float Voltage Settings (3.45V, 3.55V, 3.6V, 3.8V)
• 28-Lead 4mm × 5mm QFN Package

Typical Application

Description

The LTC®4156 is a 15 watt I2C controlled power manager with PowerPath™ instant-on operation, high efficiency switching battery charging and USB compatibility. The LTC4156 seamlessly manages power distribution from two 5V sources, such as a USB port and a wall adapter, to a single-cell rechargeable lithium iron phosphate battery and a system load.

The LTC4156’s switching battery charger automatically limits its input current for USB compatibility, or may draw up to 3A from a high power wall adapter. The high efficiency step-down switching charger is designed to provide maximum power to the application and reduced heat in high power density applications.

I²C adjustability of input current, charge current, battery float voltage, charge termination, and many other parameters allows maximum flexibility. I²C status reporting of key system and charge parameters facilitates intelligent control decisions. USB On-The-Go support provides 5V power back to the USB port without any additional components. A dual-input, priority multiplexing, overvoltage protection circuit guards the LTC4156 from high voltage damage on the V_BUS pin.

The LTC4156 is available in the low profile (0.75mm) 28-lead 4mm × 5mm QFN surface mount package.