The LTC4054ES5-4.2TRPBF is a battery-charger IC from Analog Devices. It has an input voltage range of 2.5V to 28V and is capable of providing up to 4.2A of current for charging Li-Ion/Li-Poly cells. It features automatic charging termination, charge status monitoring and protection circuitry for overvoltage, overcurrent and thermal conditions. Additionally, it has an I2C interface for communication with the host system. The part comes in a 4.9mm x 5.5mm x 0.96mm 4-lead DFN package.