Li-Ion battery switching charger speeds charge times and boost USB OTG power

November 01, 2011 // By Paul Buckley
Fairchild Semiconductor has developed the FAN5401x family of USB-compliant, Li-Ion switching chargers with full USB On-The-Go (USB-OTG) support. Building on the switch-mode topology FAN5400 family, the first device in the family, the FAN54013 offers increased max charge current of 1.45 A and increased USB OTG boost power that can support a full 500 mA at 5 V.

When charging a single-cell or parallel-cell Lithium Ion (Li-Ion) battery through a USB port or AC/DC adaptor, the switch-mode based topology of the FAN54013 provides faster charge times and overcomes the thermal issues associated with linear charger solutions in use today. Typical applications include single-cell or parallel-cell Li-Ion battery charging in devices such as cell phones, smartphones, tablets, wireless broadband hotspots, digital cameras, portable media/game players and other portable products.

In addition to providing up to 94 percent charging efficiency, the FAN54013 delivers a suite of protection features such as integrated 20 V input voltage rating, thermal protection, reverse current blocking, watchdog timers, and ±5 percent accurate input current limiting for USB compliance. USB OTG hosting is supported with an integrated 5 V 500 mA boost that uses the same inductor as the charger thereby reducing external component count.

For flexibility the FAN54013 charging parameters and operating modes are programmable through an I2C interface, which operates up to 3.4 Mbps. Available in a 1.96 x 1.87 mm, 20-bump, 0.4 mm pitch CSP package, the FAN5401x family is the smallest switch-mode solution on the market that provides both charger and full 500 mA USB-OTG 5 V boost functionality.

Fairchild’s USB expertise, combined with its broad portfolio of mobile power solutions, allows designers to innovate and differentiate their mobile offerings. By working with customers, as well as by identifying developing trends in the marketplace, Fairchild continues to develop the right power management solutions that advance mobile designs and enrich the user experience.

More information about the FAN54013 Li-Ion switching chargers at