Looking for product selection assistance. I will list some parameters, but would like to learn if there is certain ‘search criteria’ for MPS ICs that support solar input. Reason I mention is on the MPS site, there is a page referencing the MP2731 for solar applications, but the data sheet does not elude to much about that.
Design specifications.
Solar input - 5W, Voc 22VDC, max charge current 1A, battery 2S1P LiFePO4. Even if an IC does not support LiFe, if voltage parameters can be changed, we can probably make it work as the charge profile is not really ‘that’ different, just the cell voltages.
We do have this charger paired with an MCU on the following board that is referenced here in this design. I believe that this solution fits your requirements:
So MPS only offers 1 IC for solar panels and it is a 1S chip? As I was asking about a 2S. Since we are looking to purchase 50k of these, shall we stick with TI? Nothing on your site works correctly to sort chips and we don’t have weeks to spend looking at 400 data sheets.
Apologies, though I saw the reference design could support multiple cells but was mistaken. No, the MP2731 is not the only battery charger that can be used in solar applications.
You can technically use any charger in conjunction with an MCU like the MC96F1206USBN that tracks MPPT settings.
For just the battery charger portion for 2S1P, can have a max charge current of 1A, and have a Voc up to 22V, these parts should narrow down the search:
There are definitely many more candidates (as you mentioned on the website, there are hundreds), so let me know if these don’t work out for any reason. You can use the MEZS7-SolarCharger as a reference if you’d like.
I will both narrow the band, and offer a competing IC that we are considering. Keep in mind, only here because your site is not helpful.
I2C chargers only. 2. Solar Voc up to 28V. 3. 1-5A output. 4. 2-series battery compatible, or in any case set batt voltages up to 7.3V. 5. Settings will allow us to profile for LiFePO4 battery. 6. A design that can identify and use either a solar panel or rigid charge adapter on same port (not at same time).
Seems most chargers do have a form of power tracking today, just based on not knowing what charge source is being provided. However, solar presents a different challenge. We are able to create and accept manual setting of different charge profiles if using solar or a rigid source, but 90% of the time would be solar.
Competing charger is a BQ25672. Our issues are both price and very not intuitive/helpful data sheets. We are not looking to devote 5 full time engineers for 6mo just to figure out a charger. Intuitive and fast implementation is ideal, with many failure modes already baked in.
When are you projected to start production here? I would highly recommend filling out a ticket form to be paired with MPS sales in your region to get quotes on the 50k volumes as well: