SLUAA04A june   2020  – may 2023 BQ25150 , BQ25155 , BQ25618 , BQ25619 , TS5A12301E , TS5A3157 , TS5A3159A , TS5A6542

 

  1.   1
  2.   High-Efficiency Charging for TWS Using a 2-Pin Interface
  3.   Trademarks
  4. 1 Introduction
  5. 2 System Overview
    1. 2.1 Charging Case
      1. 2.1.1 BQ25619
      2. 2.1.2 TLV62568P
      3. 2.1.3 TPS22910A
      4. 2.1.4 TS5A12301E
      5. 2.1.5 MCU
    2. 2.2 Earbuds
      1. 2.2.1 BQ25155
      2. 2.2.2 TPS22910A
      3. 2.2.3 TS5A12301E
      4. 2.2.4 BT/SOC
  6. 3 Charging Case Algorithm Implementation
    1. 3.1 Initialization and Main Code
    2. 3.2 UART Interrupt and Output Voltage Adjustment
  7. 4 Earbud Algorithm Implementation
    1. 4.1 Initialization and Main Code
    2. 4.2 Interrupt and Transmission
  8. 5 Test Procedure
  9. 6 Test Results
    1. 6.1 Dynamic Voltage Adjustment
    2. 6.2 BQ25619 with 4.6-V Output
    3. 6.3 Standard Boost with 5V Output
  10. 7 Summary
  11. 8 Schematics
  12. 9 PCB Layout
  13. 10Software
    1. 10.1 Charging Case main.c
    2. 10.2 Earbuds main.c
  14. 11Revision History

6.2 BQ25619 with 4.6-V Output

The second system shown uses the boost converter of the BQ25619 with an output of 4.6 V. This solution has a higher efficiency than a system with a 5-V intermediate but still struggles with thermal performance.

GUID-20FC06E7-BA91-4992-B4E5-3DC81328A124-low.pngFigure 6-3 Charge Cycle of the BQ25619 with 4.6-V Output Design
GUID-7BA4B9B7-BB32-4756-891C-EED766D7943D-low.pngFigure 6-4 Thermal Performance of the BQ25619 with 4.6-V Output Design