10mA Wireless Li-Ion Charger with 1.2V Step-Down DC/DC Converter

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.

Applications

* Hearing Aids

* Low Power Li-Ion Powered Devices

* Wireless Headsets

* IoT Wearables

* Wireless Li-Ion Battery Charger Plus High Efficiency Multi-Mode Charge Pump DC/DC

* Wideband Rx Frequency: DC to >10MHz

* Integrated Rectifier with Overvoltage Limit

* Pin Selectable Charge Voltage: 4.1V or 4.2V

* Charge Current: 10mA (Fixed)

* Low Battery Disconnect: 3.0V