Summit Microelectronics SMB231/SMB232/SMB233 programmable battery charger

Summit Microelectronics has introduced its fourth-generation programmable battery charger integrated circuit family for single-cell Li-Ion, Li-Polymer and Li-FePO4 battery packs.

The SMB231, SMB232 and SMB233 are claimed to integrate the largest feature set in the industry, including compatibility with all relevant industry standards: USB battery charging revision 1.1, USB 2.0/USB3.0, JEITA safety, IEEE1725 and Chinese USB charging. All three products allow automatic matching between the AC/DC adapter’s current capability and the portable device’s charging requirements.

Tiny packages and minimum external components allow for small board space and reduced solution cost.

The family is suitable for a wide range of portable devices such as digital still cameras, mobile phones, digital camcorders, wireless headsets, DECT headsets, portable media/MP3 players (PMP), portable GPS navigation equipment and portable game consoles/controllers.

They simplify system designs by eliminating a number of external components and software requirements.

The devices incorporate Summit’s CurrentPath functionality to allow independent output current paths for the system and the battery, allowing the system to turn on with a missing or deeply discharged battery. This charging configuration reduces the charge and discharge cycles on the battery, extending its operating life.

The functionality also allows accurate charge termination, since the devices can detect the current flowing into the battery vs traditional solutions that can only detect the combined current for battery and system. The devices also include input current limit which allows USB500/100, USB900/150 or AC/DC operation (300 - 1500 mA).

An additional option is also available for not limiting input current, supporting high system current levels directly from the input power source, even when the battery is not present.

The packs incorporate automatic power source detection, adhering to the latest USB battery charging specification 1.1. The SMB231/2/3 devices can also detect non-USB compliant wall adapters. An automatic input current limit capability detects the maximum current capability of the AC/DC adapter and automatically programs the devices’ input current limit accordingly.

All devices adhere to the Japan Electronics and Information Technology Association safety guidelines, by preventing high charging voltage and/or current levels during certain low- and high-temperature ranges.

They operate with an input range from +3.7 to +6.2 V and safely withstand continuous input over-voltage up to +20 V (non-operating), while protecting downstream circuitry.