Tool/software:
Hello,
I’m encountering issues integrating the BQ24650 into my MPPT board. I followed the application circuit from the datasheet and also referred to the bq24650EVM evaluation board as a guide.
For the MPPSET voltage divider, I used 499kΩ and 36kΩ resistors to set the desired voltage of 17.8V.
However, when I measure the input voltage (Vin), I’m not seeing the expected 17.8V. Instead, I'm getting a higher voltage around 20V or 21V from the solar panel.
As for the VSYS, VOUT, VREF, and VREGN voltages, my measurements align with the values provided in the evaluation board datasheet.
Test and Validation made:
- Vref = 3.3V
- VMPPSET ≥ 1.2V
- VCC > SRN
- VREGN = 6V
- VOUT = 16.5V (battery disconnected); VOUT = 14.4V (battery connected)
- D4 → ON → charging
Calculations:
- VMPPSET = 17.8V = 1.2V * (1 + R17/R19)
- Where R17 = 499K and R19 = 36K
- VOUT = VBAT = 16.5V = 2.1V * (1 + R13/R15)
- Where R13 = 820K and R15 = 120K
How can I resolve this issue?
Thanks in advance!
