Universal charging solves the matching problem — Summit Microelectronics

Universal charging solves the matching problem — Summit Microelectronics

The SMB339 is a switch-mode programmable battery charger IC for single-cell Li-ion and Li-polymer powered systems (see Electronic Products , November 2008, p. 111). It is the first battery charger IC to allow USB and integrate compatibility with all relevant industry standards including USB 2.0, USB “On-The-Go” Supplement, USB battery-charging specification 1.0, IEEE1725, and the Chinese USB charging specification.

The battery charger device solves the problem of matching the various USB wall chargers (and their current limits) to the myriad portable systems that have different batteries and charge current requirements. This is the only battery charger IC on the market to automatically optimize the current drawn from a specific adapter, thereby maximizing charge current and ensuring reliable operation. This allows systems to power-up even during USB1 mode (limited to less than 100 mA from a USB port) and also to significantly reduce charging times when current-limited adapters are used (up to 750 mA from 500-mA USB source).

The charger incorporates a 3-MHz switch-mode architecture and uses a proprietary technology for a charging current of 750 mA from a 500-mA USB-source. The automatic power source detection differentiates between a USB 2.0 port and a USB ac/dc adapter. The device features an automatic input current-limit detector that identifies the ac/dc adapter’s maximum current capability from 300 mA for Chinese chargers to more than 1.5 A for USB-type chargers.

Summit Microelectronics
Sunnyvale , CA
Information 408-523-1000
http://www.summitmicro.com