Dear Texas Instruments,
I ama student in the process of designing an energy harvesting tracking device for the Wild Life Authority, Sri Lanka and I am stuck at one particular point in my design stage.
I wish to harvest Solar energy in a 15cm x 8cm solar panel.
this small unit is to replace the current costly circuit on to an elephant and I plan to use most of the TI chips in my design. this circuit has a yearly production of around 5000 units.
In this regard I had been doing research for over 2 weeks. I used TIs filters on pages and forums etc but I got no satisfactory response so i thought of explaining my problem t TI.
I am using a single cell lithium polimer battery of 5800mAh.
the phase I am stuck with is at the point choosing the right Charging Management/Energy harvesting IC for my Lipo Battery.
- the charging IC gets input voltage directly from the solar(approx6v 300mA). The o/p voltage of the Solar can be decided depending on the TI charging IC but the solar pannel must fit into 15cm x 8cm which I can mange to make a custom made soalr panel. Since the IC gets power directly from Solar , it must intelligently manage the power consumption from the solar. I suppose TIs MPPT type charger can do this.
- I want it to have a maximum efficiency so even if Solar pannels voltage drops below the voltage of the battery it must still somehow charge at low current. I think a boost charger IC can do this. And I do not prefer Linear type mainly due to its losses in power as this application is power specific.
- I would rather prefer if I can give another power input to the Charging IC from my Kinetic energy Harvesting IC.
i.e whenever te kinetic charging IC had enough charge to charge the battery I want that charge too to flow in to this Solar IC and help charge the battery. I wouldn't mind even if I have to connect both Kinetic Charger o/p and the SOlar pannel o/p to the same input of the TI charging IC
additionally
- my system operates at a voltage of 3.3v 1mA most of the time. If TIs charging IC can provide a SEPARATE power path of 3.3v, it would be really good as it then wouldnt try to confuse the charging current monitoring circuitry. If this power path can provide 2A it would be great as per day two times I draw 2A bursts for two seconds to transmit a signal. But I understand if this feature is not available I can of course use a different Chip to extract power from the battery and have a separate chip to manage charging.
Does anyone know a chip that has these features?
I would so much appreciate help from TI and consider it so valuable.
Thank you so much