SLUAAT5 December   2023 BQ25756

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1Introduction
  5. 2LiFePO4 Charging Profile
  6. 3BQ25756 Settings For LiFePO4
    1. 3.1 Set Charging Voltages
      1. 3.1.1 Regulation Voltage
      2. 3.1.2 Recharge Voltage
      3. 3.1.3 Battery Low Voltage
    2. 3.2 Set Charging Current
      1. 3.2.1 Charging Current
        1. 3.2.1.1 ICHG Pin Pull Down Resistor
        2. 3.2.1.2 ICHG_REG Register Bits
      2. 3.2.2 Pre-Charge Current
      3. 3.2.3 Termination Current
    3. 3.3 TS Pin Setting
      1. 3.3.1 JEITA Enabled
      2. 3.3.2 JEITA Disabled
      3. 3.3.3 NTC Monitoring Disabled
  7. 4Supercapacitor Charging Profile
  8. 5SBQ25756 Settings For Supercapacitor
    1. 5.1 Charge Current Setting
    2. 5.2 Charge Voltage Setting
    3. 5.3 TS Pin Setting
  9. 6Test Results From EVM
    1. 6.1 Charging LiFePO4 Battery
    2. 6.2 Charging Supercapacitor
  10. 7Summary
  11. 8References

5.1 Charge Current Setting

Supercapacitors does not require trickle charge or pre-charge when their voltage is low. Supercapacitors can be charged with fast charge current even when the voltage is zero. The termination current setting is also not required. For setting EN_PRECHHARGE bit to 0 disables both trickle charge and pre-charge. The charge timer can be disabled as well. To use optimum charge current, the settings in Table 5-1 can be used.

Table 5-1 Supercapacitor Charge Current Settings
Settings Value Register
EN_PRECHG 0 REG0x14
EN_TERM 0 REG0x14
EN_CHG_TMR 0 REG0x15

The desired fast charge current can be set using the method described in Section 3.2.1.