The MAX8895 battery charger for Bluetooth headsets and portable devices uses automatic adapter detection and USB enumeration for charging without system software or an external microcontroller for stand-alone charging.
The unit’s Smart Power Selector provides seamless distribution of power from the USB power input (VBUS) to the battery and system load for simultaneous charging of the battery while powering the system, as well as operating the portable device with a discharged battery or no battery. The battery supplements VBUS when the system load exceeds the VBUS input current limit.
The charger features a battery-disconnect switch, currentsense circuit, thermal-regulation circuitry, MOSFET pass elements, and overvoltage protection up to 16 V. Flexible programming options include fast-charge current, termination current, and chargetimer duration. The MAX8895 also supports adaptive battery charging, which reduces charge current when necessary to prevent the charge source from collapsing.
Two USB options are available. The MAX8895X (low speed) and the MAX8895Y (full speed) operate from a 4.0 to 6.6-V supply. The MAX8895 is specified for –40 to 85°C.
Maxim Integrated Products, 120 San Gabriel Dr., Sunnyvale, CA 94086, (408) 737-7600, www.maxim-ic.com