Smartwatch Battery Management Solution Reference Design


Design files


This reference design is for smartwatch battery management solution (BMS). It is suitable for low-power wearable devices like smartwatch applications. The design includes an ultra-low current 1 cell Li-ion linear charger; a highly integrated Qi-compliant wireless power receiver; a cost-effective voltage and current protection integrated circuit; a system-side with integrated sense resistor battery fuel gauge and a booster with output up to 28 V for LCD display devices.

The design is implemented in a small size (20 mm x 29 mm) PCB; its input power can be either from a micro-USB connector or Qi-compliant wireless power transmitter and the wireless power transmitter will be turned off whenever 5-V power supply from micro-USB connector is detected.

  • Charger with buck and LDO output programmable for system
  • Manual reset timer output for system reset
  • Wireless Receiver with 93% efficiency optimized (only one IC required)
  • Wireless power consortium (WPC) V1.1 compatible in size of 1.9 mm x 3.0 mm
  • Fuel gauge with Impedance Track gas gauging and virtually plug-n-play
  • Battery protection IC is a cost-effective solution for full protection of both voltage and current, charging and discharging.
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A fully assembled board has been developed for testing and performance validation only, and is not available for sale.

Design files & products

Design files

Download ready-to-use system files to speed your design process.

TIDUB09.PDF (1494 K)

Reference design overview and verified performance test data


Detailed schematic diagram for design layout and components


Complete listing of design components, reference designators, and manufacturers/part numbers


Detailed overview of design layout for component placement


Files used for 3D models or 2D drawings of IC components


Design file that contains information on physical board layer of design PCB


PCB layer plot file used for generating PCB design layout


Includes TI products in the design and potential alternatives.

AC/DC & DC/DC converters (integrated FET)

TPS6104628-V Output Voltage Boost Converter in WCSP Package

Data sheet: PDF | HTML
Battery charger ICs

BQ25120A300-mA linear battery charger with Power Path, integrated LDO and buck converter 1.8V default output

Data sheet: PDF | HTML
Battery charger ICs

BQ51003BQ51003 Wireless power Receiver

Data sheet: PDF | HTML
Battery fuel gauges

BQ27421-G1System-side(tm) fuel gauge with integrated Sense Resistor | battery gas gauge

Data sheet: PDF | HTML
Battery protectors

BQ2970Li-Ion/Li Polymer Advanced Single-Cell Battery Protector IC Family

Data sheet: PDF | HTML

CSD75208W1015-20-V, P channel NexFET™ power MOSFET, dual Common Source WLP 1 mm x 1.5 mm, 108 mOhm, gate ESD prot

Data sheet: PDF | HTML

CSD83325L12-V, N channel NexFET™ power MOSFET, dual LGA, 5.9 mOhm, gate ESD protection

Data sheet: PDF | HTML

Technical documentation

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Type Title Date
* Design guide Battery Management for Smartwatch and Wearable Applications Design Guide Nov. 09, 2015

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