SLUAAG9 September   2021 BQ25170 , BQ25171-Q1 , BQ25175

 

  1.   Trademarks
  2. 1Introduction
  3. 2BQ25171-Q1 Design Decisions
  4. 3700 mA/70 mA Variable Charge Current Li-Ion Fast Charge Design
  5. 4200 mA Time Charge 3S NiMH Design
  6. 545 mA Fast Charge LiFePO4 Design
  7. 6Pin Configuration
  8. 7R-ISET Common Values
  9. 8Common Questions: Tips and Tricks

2 BQ25171-Q1 Design Decisions

The device requires a minimum number of external parts to implement a charging solution. The standard solution only requires the selection of three external resistors to configure the device to given charge specifications.

  1. CHM_TMR – Resistor value to select battery chemistry and charge timer, see table 7-1 in Data sheet.
  2. VSET – Resistor value to program charge voltage and enable optional intermittent charge (for NiMH only), see table 7-2 in Data sheet.
  3. ISET – Resistor value to set fast charge current, see Table 7-1 in this application note.
  4. Other connections:
    1. TS – NTC to monitor battery temperature, typically 10 kΩ.
    2. Cin and Cout – 1 µF effective capacitance connection to ground at both IN and OUT
    3. STAT1 and STAT2 – Open collector status outputs (optional connections)
    4. /CE – Charge enable input (optional connection)