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Fairchild Semiconductor FAN5400 USB-Compliant Li-Ion Battery Switching Chargers

The Fairchild Semiconductor FAN5400 family of USB-compliant Li-Ion battery switching chargers address the need for faster charge times for Li-Ion batteries in portable devices and overcome the thermal issues associated with linear chargers. The Fairchild FAN5400 family is a winner in the annual Top-10 DC-DC Power Product Awards hosted by Electronic Products China (EPC). The charging parameters and operating modes of Fairchild FAB540x battery switching chargers are programmable through an I²C interface that operates at up to 3.4Mbps. A maximum charge current of 1.25A ensures fast charging times, and a high charge voltage accuracy (±0.5 percent @25°C) allows for more "topping out" of the battery, resulting in longer battery life. In addition to the standard thermal and short circuit protections, the FAN5400 family can sustain up to 20V DC on the input, in order to protect against unregulated over-voltage conditions on the USB port. These devices provide highly efficient re-charging either through a USB port or a 5V AC/DC adapter and remain cool while re-charging. These Li-Ion battery switching chargers are an ideal solution for recharging single-cell and parallel-cell Li-Ion batteries, outperforming the traditional linear charger while providing a convenient USB On-The-Go (USB-OTG) capability.

Features

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
20V Absolute Maximum Input Voltage
6V Maximum Input Operating Voltage
1.25A Maximum Charge Rate
Programmable through High-Speed I²C Interface (3.4Mb/s) with Fast Mode Plus Compatibility
3MHz Synchronous Buck PWM Controller with Wide Duty Cycle Range
Small Footprint 1µH External Inductor
Safety Timer with Reset Control
1.8V Regulated Output from VBUS for Auxiliary Circuits
5V, 300mA Boost Mode for USB OTG for 2.5 to 4.5V Battery Input