Energy Harvesting from Single Cell Solar Panel for Li-ion Battery – Reference Design
The TIDA-050039 reference design from Texas Instruments demonstrates how to use a fully-integrated synchronous boost converter TPS61089 in combination with a single-cell solar panel to charge a Li-ion battery for high output power applications.
An additional maximum power point (MPP) sampling network is implemented to dynamically control the input voltage to optimize the transfer of power from solar panel. By using the high current capability, high-efficiency boost converter TPS61089, Li-ion battery maximum charging current is up to 200mA.
Features
- Low working input voltage range: 0.4 - 0.6V
- Fixed Maximum Power Point (MPP)
- Maximum charging current up to 200mA
- Low cost
- Simple and flexible
TIDA-050039 block diagram (click on image to enlarge)
The image above shows the block diagram of TIDA-050039. Since the boost converter TPS61089 input voltage undervoltage lockout (UVLO) rising threshold is 2.7V, Li-ion battery voltage could be used as input voltage of TPS61089 assumed Li-ion battery minimum voltage is higher than 3.0V.
Once it starts up and keeps switching, the discrete charge pump circuit outputs a 2 × Vout voltage to supply Vin pin in order to decrease TPS61089 Rdson, therefore efficiency is increased. Energy is obtained from solar panel and stepped up to charge a Li-ion battery with MPP control.
