Industry's Smallest 1.55A 1-Cell Li+ DC-DC Charger

The MAX8971 is a compact, high-frequency, high-efficiency switch-mode charger for a one-cell lithium-ion (Li+) battery. It delivers up to 1.55A of current to the battery from inputs up to 7.5V and withstands transient inputs up to 22V. The 4MHz switch-mode charger is ideally suited for small portable devices, such as Bluetooth® headsets, AR/VR glasses, and other lithium-ion powered accessories. It minimizes component size and heat.

Battery-protection features include: low-voltage prequalification, charge fault timer, die temperature monitoring, and battery temperature monitoring. The battery temperature monitoring adjusts the charge current and termination voltage for safe use of secondary lithium-ion batteries.

The IC accepts either a general DC input or USB. It has programmable automatic input-current limiting to protect upstream charging sources such as USB.

Charge parameters are easily adjustable through an I²C interface. Charge is terminated based on user-selectable minimum current level. Charge status is provided to the application processor through an interrupt pin.

The IC is available in a space-saving, 20-bump, 2.18mm x 1.62mm WLP package.

Applications

* AR/VR Glasses * Bluetooth Headsets * Hearables * Portable Devices * Smartphones * USB Charging * Wearables

* Switch-Mode Charger

* High-Efficiency

* Low Heat

* Fast Charge Time

* Small and Simple

* Precise

* Up to ±5% Current Regulation and 0.5% Voltage Regulation

* Safe

* JEITA Battery Temperature Monitor

* Over/Undervoltage Protection, Safety Timers, Temperature Regulation

* USB Friendly

* Flexible

* Programmable Voltage/Current

* Status/Interrupts Through I2C

* Automatic Input Current Limit

* I2C Interface

* Input Current Limit (100mA to 1500mA)

* Fast-Charge/Termination Current (250mA to 1550mA)

* Charge Voltage

* 4.1V, 4.15V, 4.2V, 4.35V (MAX8971EWP+ and MAX8971GEWP+)

* 4.35V, 4.40V, 4.45V, 4.50V (MAX8971BEWP+)

* Termination Enable

* +22V Absolute Maximum Input Voltage Rating

* Up to 7.5V Maximum Operating Input Voltage

* 5V USB/Safeout LDO for USB PHY

* 2.3A GSM RF Test Mode (Factory Testing)

* Charge Current to Voltage Conversion (VICHG) for Baseband ADC

* Reverse Battery Leakage Protection

* Input/Output Overvoltage Protection

* Interrupt Status Output