MAX77301 JEITA-Compliant Li-Ion Battery Charger

The MAX77301 is a JEITA-compliant Li-ion linear battery charger that works with a USB interface, a dedicated charger, or a universal adapter. The IC provides automatic adapter type detection and counting with a USB host or hub. The IC integrates an independent battery charging switch, current sensing circuit, MOSFET pass element, thermal regulation circuit, and eliminates the external Schottky diode reverse blocking to create the simplest and smallest USB-compliant charging solution.

The IC includes automatic detection of the charging adapter type, allowing us to distinguish between USB 2.0 devices, USB chargers, proprietary charging devices, and standard input adapters. For a complete data sheet, see Table 2. When enumeration is enabled, the IC automatically negotiates with the USB host to enable the highest possible charge current that can be obtained from a USB 2.0 device or USB charger without processor intervention. Adapter type detection complies with USB 2.0 and Battery Charging Specification Revision 1.1.

The IC controls the charging process of a single-cell Li+ battery from battery voltage detection, prequalification, fast charge, over-charging, and charge termination. The charging process is controlled using constant current, constant voltage, and constant die-temperature (CCCVCTj) regulation to continue safe operation under all conditions. The IC also meets JEITA battery charging requirements.

Intelligent Power Selector feature makes best use of limited USB or adapter power. Battery charging current can be set independently of input current limit. Power not used by the system is used to charge the battery. The battery assists the input source when needed. Maintaining system voltage allows applications to operate with no battery, a discharged battery, or a dead battery. Automatically switches the system between battery and external power.

The I2C interface provides full programmability of the battery charging characteristics, input current limit and protection functions. This provides flexibility in adapter and battery size and wide range of uses.

Other features include undervoltage lockout (UVLO), overvoltage protection (OVP), charge status flag, charge fault flag, input power OK indicator, battery detection, JEITA compliant charging, charge timer, output 3.3V/10mA auxiliary, and an external power switch.

Key Features

Rechargeable from USB port

Automatically detect adapter type

Input current up to 1500mA Charge current up to 900mA

Enumeration without processor intervention

Support USB low speed and full speed

Compliant with USB 2.0 Specification and Battery Charging Specification (Revision 1.1)

Comply with the new generation of low voltage lithium-ion battery introduction

Input overvoltage protection up to 16V

Smart Power Selector™ allows de-energized or no-battery power path operation

with open protection battery detection, including pack

Thermal regulation prevents overheating

Charge complete, pre-charge, LED indicators and time/temperature error

Serial I2C compatible interface (400kHz)

6μA (typ) shutdown current

2.44mm" x 2.44mm, 25-bump WLP package