SLUAAI1 December   2021 BQ25798

 

  1.   Trademarks
  2. 1Introduction
  3. 2Solar Battery Charging with the BQ25798
    1. 2.1 Making Use of FOCV
    2. 2.2 BQ25798 Key Features for MPPT
    3. 2.3 BQ25798 Key Registers
    4. 2.4 BQ25798 MPPT Algorithm
    5. 2.5 Using Charge Current for Algorithm Improvement
    6. 2.6 Second Algorithm in Action
  4. 3Summary
  5. 4References

2.2 BQ25798 Key Features for MPPT

To implement these key requirements for a solar charger, we need a charger that:

  1. Can disable its input
  2. Can measure the OCV
  3. Can set the K-factor
  4. Can hold the input voltage at the MPP

The BQ25798 is the perfect candidate and meets all of these requirements. First, it has a Hi-Z mode that allows disabling of the input. Second, it has an ADC that can measure the OCV. Third, it has an I2C register to set the K-factor. Last, it has flexible Input Voltage Dynamic Power Management (VINDPM) to hold the solar panel voltage at the MPP voltage. See Figure 2-1 for BQ25798 features that enable MPPT.

GUID-20211117-SS0I-6R5F-08SH-NQRGVJ7PWFGX-low.gifFigure 2-1 BQ25798 Integration and Features