The MAX8895_ USB-compliant linear battery chargers operate from either a USB port or dedicated charger with automatic detection of adapter type and USB enumeration capability. The MAX8895X/MAX8895Y integrate the battery disconnect switch, current-sense circuit, MOSFET pass elements, and thermal regulation circuitry, and eliminate the external reverse-blocking Schottky diode to create the simplest and smallest stand-alone charging solutions.
The MAX8895_ include an automated detection of charge adapter type, making it possible to distinguish between USB 2.0 device, USB charger, and dedicated charger devices. Furthermore, the MAX8895X/MAX8895Y include a USB enumeration function that automatically negotiates with a USB host, making it possible to achieve the highest current available from a USB 2.0 device or USB charger without processor intervention. The adapter type detection is compliant with USB 2.0 specification as well as USB charging Revision 1.1.
The MAX8895_ control the charging sequence for single-cell Li+ batteries from initial power-OK indication, through prequalification, fast-charge, top-off, and finally charge termination. Charging is controlled using constant current, constant voltage, and constant die-temperature (CCCVCTj) regulation for safe operation under all conditions. The maximum charging current is adaptively controlled by subtracting the system current from the input current limit, ensuring that the charging current is always maximized for any given operating condition.
The MAX8895_ feature optimized smart power control to make the best use of limited USB or adapter power. Battery charge current is set independently of the SYS_ input current limit. Power not used by the system charges the battery. Automatic input selection switches the system from battery to external power. This allows the application to operate without a battery, discharged battery, or dead battery.
Other features include undervoltage lockout (UVLO), overvoltage protection (OVP), charge status flag, charge fault flag, power-OK monitor, battery thermistor monitor, charge timer, and a 3.3V output.
The MAX8895_ operate from a +4.0V to +6.6V supply and include overvoltage protection up to +16V. The MAX8895_ are specified over the extended temperature range (-40°C to +85°C) and are available in a compact 2.36mm x 2.36mm, 25-bump WLP package (0.4mm pitch).
Applications
- Bluetooth® Headsets
- Charging Cradles
- Portable Devices
