SLUA748A December   2015  – April 2016 BQ25120 , BQ51003 , TPS61046 , TPS61240 , TPS62743

 

  1.   Trademarks
  2.   Power Management Reference Design for a Wearable Device with Wireless Charging Using the bq51003 and bq25120
    1. 1 Wearable Power Design
      1. 1.1 Wireless Charging Input
      2. 1.2 Battery Charger, MCU, Radio, and Sensor Power
      3. 1.3 Second Buck Output for MCU, Radio or Sensor
    2. 2 PMOLED Display Power Design
    3. 3 Heart Rate Monitor or e-Ink Power Design
    4. 4 Layout Guidelines for Wearable Design
      1. 4.1 Wireless Receiver (bq51003)
      2. 4.2 Linear Charger (bq25120)
      3. 4.3 Buck Converter (TPS62743/6)
      4. 4.4 Boost Converters (TPS61046 and TPS61240)
      5. 4.5 General Considerations
    5. 5 References
  3. AExperimental Results
    1. A.1 Experimental Results
  4.   Revision History

3 Heart Rate Monitor or e-Ink Power Design

The TPS61240 is a high efficiency boost converter optimized for lithium-ion battery input and fixed 5-V output application. it features 3.5 MHz switching frequency and only needs three small surface-mount external components as shown in Figure 7 with solution size smaller than 13 mm2. The 5-V output can be used to power the heart rate monitor module or e-Ink display in a wearable device

The function, characteristics and external component selection are found in the datasheet

schematic_heart_rate_slua748.gifFigure 7. Schematic of Boost for Heart Rate Monitor Power