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.ApplicationsAR/VR GlassesBluetooth HeadsetsHearablesPortable DevicesSmartphonesUSB ChargingWearables