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Wearable devices require advanced power management to achieve long battery run times with always-on functionality. Additionally, the devices need to use small rechargeable batteries and enable small footprint designs. This application note shows the implementation of a scalable power management solution for wearables that can be tailored for activity monitors, watches, and more. The design provides a wireless charging input, highly configurable battery management solution with Li-Ion battery charger and low quiescent current (Iq) DC/DC buck, boost converter for PMOLED display, boost converter for Heart Rate Monitor (HRM), and low Iq DC/DC buck.
DESCRIPTION | VALUE |
---|---|
Input Voltage (VIN) | 5 V USB input or Qi Wireless Transmitter |
Input Current | Up to 500 mA |
Output Voltage for Li-Ion Battery | 3.6 V to 4.65 V |
Fast Charge Current For Li-Ion Battery | 5 mA to 300 mA |
Termination Current for Li-Ion Battery | 500 µA to 37 mA |
Output Voltage for MCU (SYS rail) | 1.8 V nominal (Adjustable from 1.1 V to 3.3 V) |
Output Current for MCU (SYS rail) | Up to 300 mA |
Output Voltage for Second Buck Rail | 1.8 V |
Output Current for Second Buck Rail | Up to 300 mA |
Output Voltage for PMOLED Display | 12 V |
Output Current for PMOLED Display | Up to 100 mA |
Output Voltage for Heart Rate Monitor | 5 V |
Output Current for Heart Rate Monitor | Up to 300 mA |
Output Voltage for Sensors or Radio (LDO) | 0.8 V to 3.3 V |
Output Current for Sensors or Radio (LDO) | Up to 100 mA |