Hello!
Our company is looking for an ultra-low power solar charging MPPT chip solution. Please recommend some suitable chip models, along with specifications, reference design diagrams, etc.
1. The open-circuit voltage of the solar panel is 6V, and the short-circuit current is 12.9mA.
2. The charging battery in the subsequent stage is a 4.2V cutoff charging voltage.
3. The MPPT needs to supply power to both the battery and the subsequent load. The load voltage is approximately 3V, which means the MPPT must provide a voltage that is adjustable and can be stepped down, and it would be best if it could be separated from the battery charging voltage.
4. When our solar panel charges the battery at 6V, it drops to 4.2V. This direct charging efficiency is relatively low, so we have introduced the MPPT, hoping to improve the charging efficiency.
5. If the MPPT can monitor overvoltage, overcurrent, undervoltage, and undervoltage of the battery, that would be best.
If SPV1050 is used, my questions are as follows.
1. How is the MPPT (Maximum Power Point Tracking) achieved? CVT (Constant Voltage), P&O (Perturbation and Obstruction) Observation method), IncCond(Incremental conductance method).
2. How to set MPPT through R1-R2-R3? For example, if the open-circuit voltage of my photovoltaic panel is 6V, and the tentative MPPT voltage is 6 * 0.8 = 4.8V, then what are the resistance values of these three resistors?
3. The battery charging cut-off voltage is 4.2V, and the under-voltage is 3.6V. How to set the values of R4-R5-R6?
4. How were the R1-R2-R3 in the schematic diagram of the development board STEVAL-ISV020V1 calculated? What is the MPPT setting voltage for it?
5. How were the following parameters of the development board STEVAL-ISV020V1 set?
6.when the inupt current >20mA，what is the efficency?
Thanks.
