onsemi FAN54015UCX

The FAN54015 combines a highly integrated switch-mode charger, to minimize single-cell Lithium-ion (Li-ion) charging time from a USB power source, and a boost regulator to power a USB peripheral from the battery. The charging parameters and operating modes are programmable through an I²C Interface that operates up to 3.4 Mbps. The charger and boost regulator circuits switch at 3 MHz to minimize the size of external passive components. The FAN54015 provides battery charging in three phases: conditioning, constant current and constant voltage. To ensure USB compliance and minimize charging time, the input current limit can be changed through the I²C by the host processor. Charge termination is determined by a programmable minimum current level. A safety timer with reset control provides a safety backup for the I²C host. Charge status is reported to the host through the I²C port. The integrated circuit (IC) automatically restarts the charge cycle when the battery falls below an internal threshold. If the input source is removed, the IC enters a high-impedance mode, preventing leakage from the battery to the input. Charge current is reduced when the die temperature reaches 120°C, protecting the device and PCB from damage. The FAN54015 can operate as a boost regulator on command from the system. The boost regulator includes a soft-start that limits inrush current from the battery and uses the same external components used for charging the battery.

• Fully Integrated, High-Efficiency Charger for Single-Cell Li-Ion and Li-Polymer Battery Packs
• Faster Charging than Linear
• Charge Voltage Accuracy: ±0.5% at 25°C, ±1% from 0 to 125°C
• ±5% Input Current Regulation Accuracy
• ±5% Charge Current Regulation Accuracy
• 20 V Absolute Maximum Input Voltage
• 6 V Maximum Input Operating Voltage
• 1.45 A Maximum Charge Rate
• Programmable through High-Speed I²C Interface (3.4 Mb/s) with Fast Mode Plus Compatibility – Input Current – Fast-Charge / Termination Current – Charger Voltage – Termination Enable
• 3 MHz Synchronous Buck PWM Controller with Wide Duty Cycle Range
• Small Footprint 1 μH External Inductor
• Safety Timer with Reset Control
• 1.8 V Regulated Output from VBUS for Auxiliary Circuits
• Dynamic Input Voltage Control
• Low Reverse Leakage to Prevent Battery Drain to VBUS
• 5 V, 500 mA Boost Mode for USB OTG for 3.0 V to 4.5 V Battery Input
• Available in a 1.96×1.87 mm, 20-bump, 0.4 mm Pitch WLCSP Package

• Cell Phones, Smart Phones, PDAs
• Tablet, Portable Media Players
• Gaming Device, Digital Cameras