The LTC4126-10 is a low-power wireless single-cell Li-Ion battery charger with an integrated step-down DC/ DC regulator. The step-down regulator is a low-noise multimode charge pump which is powered from the battery and provides a regulated 1.2V at the output. The switching frequency is set to either 50kHz or 75kHz depending on the mode to keep any switching noise out of the audible range.The LTC4126-10 charger is a full-featured constant-current constant-voltage Li-Ion battery charger with automatic recharge, automatic termination by safety timer, and battery temperature monitoring via an NTC pin. Charge current is fixed at 10mA with a 3-hour termination timer. Undervoltage protection disconnects the battery from all loads when the battery voltage is below 3.0V.The tiny 2mm × 2mm LQFN package and minimal external component count make the LTC4126-10 well suited for Li-Ion battery powered hearing aid applications and other low power portable devices where a small solution size is required.ApplicationsHearing AidsLow Power Li-Ion Powered DevicesWireless HeadsetsIoT Wearables