The LTC4126-10 from Analog Devices is a Wireless Single-Cell Li-Ion Charger IC that has been designed for Li-ion battery-powered hearing aid applications and other low-power portable devices where a small-size solution is required. It requires an input voltage of 2.7 - 5.5 V. This charger integrates a step-down DC-DC regulator, which is a low-noise multi-mode charge pump that provides a regulated output voltage of 1.2 V. It allows the switching frequency to be set either at 50 kHz or 75 kHz depending on the mode selected, thereby preventing any switching noise from entering the audible range.

This wireless charger supports automatic recharge, automatic termination by a safety timer, and battery temperature monitoring via a negative temperature coefficient (NTC) pin. It disconnects the battery using the under-voltage protection unit when the battery voltage reaches below 3 V. This charger IC is available in a thermally-enhanced surface-mount package that measures 2 x 2 mm and is ideal for low-power portable applications such as hearing aids, low-power Li-ion-powered devices, wireless headsets, IoT, and wearable applications.