Summary of MAXIM INTEGRATED MAX77301 LITHIUM-ION LINEAR BATTERY CHARGER
Maxim Integrated’s MAX77301 is a JEITA-compliant linear charger for single-cell Li-ion batteries that auto-detects adapter type and supports USB or dedicated adapters. It negotiates USB enumeration without processor intervention, provides CCCVCTj charging with JEITA support, integrates MOSFETs, current sense, thermal regulation, and eliminates an external Schottky diode. Features include Smart Power Selector power-path operation, up to 1500mA input and 900mA charge current, I2C interface, LED indicators, input overvoltage protection to 16V, and a compact 2.44mm x 2.44mm WLP package.
Parts used in the MAX77301 Lithium-ion Linear Battery Charger:
- Maxim MAX77301 IC (2.44mm x 2.44mm, 25-Bump WLP)
- Single-cell Li-ion battery
- USB port or USB host/hub for power and enumeration
- Dedicated charger or universal adapter (optional)
- Input decoupling capacitors (as recommended for USB power stability)
- Battery decoupling/output capacitors
- PCB with appropriate footprint for 25-bump WLP
- LED indicator(s) for charge done, precharge, and error
- I2C-compatible serial interface connections (SDA, SCL)
- Optional external MOSFETs or pass elements (if required by design)
Maxim MAX77301 Lithium-ion Linear Battery Charger is JEITA-compliant and operates from a USB port, a dedicated charger, or a universal adapter. The IC provides automatic adapter-type detection and enumeration with a USB host or hub. The IC integrates an independent battery charge switch, current sense circuit, MOSFET pass elements, thermal regulation circuitry and eliminates the external reverse-blocking Schottky diode. This feature creates the simplest and smallest USB-compliant charging solution.
The Maxim MAX77301 includes automated detection of charge adapter type, making it possible to distinguish USB 2.0 devices, USB chargers, dedicated charger devices, as well as standard input adapters. When enumeration is enabled, the IC automatically negotiates with a USB host, making it possible to achieve the highest charging current available from a USB 2.0 device or USB charger without processor intervention. The adapter type detection is compliant with USB 2.0 as well as battery charging Specification Revision 1.1.
Block Diagram
The IC controls the charging sequence for single-cell Li+ batteries from battery detection, pre-qualification, fast charge, top-off, and charge termination. Charging is controlled using constant current, constant voltage, and constant die-temperature (CCCVCTj) regulation for safe operation under all conditions. The IC is also compliant with JEITA battery charging requirements.
Features
- Enables charging from a USB port
- Automatic detection of adapter type
- Input current up to 1500mA and charging current up to 900mA
- Enumeration without processor intervention
- Supports USB low-speed and full-speed
- Compliant with USB 2.0 specification and battery charging specification (Revision 1.1)
- Compliant with next-generation low-voltage Li-Ion battery profiles
- Input overvoltage protection up to 16V
- Smart Power Selector™ allows power path operation with discharged or no battery
- Battery detection including packs with open protectors
- Thermal regulation prevents overheating
- LED indicator for charge done, precharge, and time/temperature error
- Serial (400kHz) I2C-compatible interface
- 6µA (Typ.) shutdown current
- 2.44mm x 2.44mm, 25-Bump WLP package
The Smart Power Selector feature makes the best use of limited USB or adapter power. The battery charge current is set independent of the input current limit. Power not used by the system charges the battery. The battery assists the input source when needed. System voltage is maintained by allowing the application to operate without a battery, a discharged battery, or a dead battery. Automatic input selection switches the system from battery to external power.
Read more: MAXIM INTEGRATED MAX77301 LITHIUM-ION LINEAR BATTERY CHARGER
- Can the MAX77301 charge from a USB port?
Yes. The MAX77301 enables charging from a USB port and supports USB enumeration. - Does the MAX77301 detect adapter type automatically?
Yes. The IC automatically detects adapter type including USB 2.0 devices, USB chargers, and dedicated chargers. - How does the MAX77301 negotiate charging current with a USB host?
When enumeration is enabled, the IC automatically negotiates with a USB host to achieve the highest available charging current without processor intervention. - What charging regulation methods does the MAX77301 use?
It uses constant current, constant voltage, and constant die-temperature (CCCVCTj) regulation. - Is the MAX77301 compliant with JEITA and USB specifications?
Yes. It is JEITA-compliant and conforms to USB 2.0 and Battery Charging Specification Revision 1.1. - What are the input and charging current limits?
The IC supports input current up to 1500mA and charging current up to 900mA. - Does the MAX77301 provide thermal protection?
Yes. It includes thermal regulation circuitry to prevent overheating. - What is the Smart Power Selector feature?
Smart Power Selector allows power-path operation so the battery and input source share power, with the battery assisting the input when needed and the system able to operate without a battery. - Does the MAX77301 require an external Schottky diode?
No. The IC integrates MOSFET pass elements and eliminates the need for an external reverse-blocking Schottky diode. - What package does the MAX77301 come in?
It is available in a 2.44mm x 2.44mm, 25-Bump WLP package.
