EVALUATION KIT AVAILABLE Click here to ask about the production status of specific part numbers. MAX77301/MAX77301A JEITA-Compliant, Li+ Charger with Smart Power Selector, Automatic Detection, and USB Enumeration General Description Benefits and Features The MAX77301 is a JEITA-compliant* lithium-ion linear Enables Charging from a USB Port battery charger that operates from a USB port, a dedi- Automatic Detection of Adapter Type cated charger, or universal adapter. The IC integrates in- Input Current Up to 1500mA and Charging Current Up dependent battery charge switch, current sense circuit, to 900mA MOSFET pass elements, thermal regulation circuitry, and Enumeration Without Processor Intervention eliminates the external reverse-blocking Schottky diode to Supports USB Low-Speed and Full-Speed create the simplest and smallest USB-compliant charging Compliant with USB 2.0 Specification and Battery solution. Charging Specification (Revision 1.1) Compliant with Next Generation Low-Voltage Li-Ion The IC includes automated detection of charge adapter Battery Profiles type, making it possible to distinguish USB 2.0 device, Input Overvoltage Protection Up to 16V USB charger, dedicated charger devices as well as stan- Smart Power Selector Allows Power Path Operation dard input adapters. When enumeration is enabled, the IC with Discharged or No Battery automatically negotiates with a USB host, making it possi- Battery Detection Including Packs with Open ble to achieve the highest-charging current available from Protectors a USB 2.0 device or USB charger without processor inter- Thermal Regulation Prevents Overheating vention. The adapter type detection is compliant with USB LED Indicator for Charge Done, Precharge, and Time/ 2.0 as well as battery charging Specification Revision 1.1. Temperature Error The IC controls the charging sequence for single-cell 2 Serial (400kHz) I C-Compatible Interface Li+ batteries from battery detection, prequalification, fast 6A (typ) Shutdown Current charge, top-off, and charge termination. Charging is con- 2.44mm x 2.44mm, 25-Bump WLP Package trolled using constant current, constant voltage and con- stant die-temperature (CCCVCTj) regulation for safe op- Ordering Information appears at end of data sheet. eration under all conditions. The IC is also compliant with JEITA battery charging requirements. Simplified Operating Circuit 4.0V TO 6.6V The Smart Power Selector feature makes the best use of (+16V OVP) limited USB or adapter power. Battery charge current is BUS SYS V BUS set independent of the input current limit. Power not used SYSTEM by the system charges the battery. The battery assists the LOAD 2 input source when needed. System voltage is maintained I C CHARGE AND CONTROL SYS LOAD by allowing the application to operate without a battery, a LOGIC SWITCH discharged battery, or a dead battery. Automatic input se- D+ USB 1-CELL LI-ION BATT lection switches the system from battery to external pow- D- INTERFACE er. 2 OSC The I C interface provides full programmability of battery MAX77301 charge characteristics, input current limit, and protection features. This provides flexibility for use with a wide range of adapter and battery sizes. Smart Power Selector is a trademark of Maxim Integrated Other features include undervoltage lockout (UVLO), over- Products, Inc. voltage protection (OVP), charge status and fault flags, in- put power-OK monitor, charge timer, 3.3V/10mA auxiliary *U.S. Patent 6,507,172 output, and an external power-on switch. Applications Smartphones, Bluetooth Headsets AR/VR Glasses Hearables, Wearables Portable Devices 19-6556 Rev 1 12/20MAX77301/MAX77301A JEITA-Compliant, Li+ Charger with Smart Power Selector, Automatic Detection, and USB Enumeration TABLE OF CONTENTS General Description 1 Applications 1 Benefits and Features 1 Simplified Operating Circuit 1 Absolute Maximum Ratings 6 Package Information . 6 WLP . 6 Electrical Characteristics . 6 Typical Operating Characteristics . 15 Pin Configuration . 19 Pin Description 19 Detailed Description 22 Overview 23 Data Contact Detection . 23 Power-On Reset . 23 Interrupt Request (IRQ) . 23 USB Interface . 24 D+ and D- . 26 Low/Full Speed . 26 Adapter Detection 26 Low-Power Mode 26 USB Suspend . 27 Keyboard Test Mode . 29 Wake-Up and USB Resume 30 USB Enumeration 30 Smart Power Selector 34 System Load Switch 34 Input Limiter 35 Setting Input Current Limit . 35 Minimum V Threshold . 35 SYS Input Current Limit . 35 Power Monitor Output (UOK) . 36 Soft-Start 36 Battery Charger . 37 Charge Enable . 39 Charge Termination (EOC) 40 CHG TYPE 40 IBUS DEF . 40 Charge Status (CHG STAT) . 40 www.maximintegrated.com Maxim Integrated 2