In application such as power banks and other devices—where the system needs to run and charge the battery at the same time—power‑path charging is a great solution.
This approach helps optimize battery performance and extend its overall lifecycle by efficiently managing power distribution between the system and the battery.
The system intelligently manages the power input by selecting from three sources:
- an AC‑to‑DC adapter,
- a solar panel, or
- the battery itself.
Normally, the adapter or the solar panel charges the battery.
If both inputs fail—for example, the AC-to-DC adapter fails and the solar panel voltage drops too low —the system automatically switches to the charged backup battery to keep supplying power to the load.
The output from the LTC4416 power‑path controller goes into the LTC4162-L, which supports input voltages up to 35 V and can run even if the battery is empty or missing. It features integrated maxi-mum power point tracking (MPPT) to enhance solar energy conversion efficiency.
Under bright sunlight, a solar panel works in two regions:
- high voltage, low impedance, and
- lower voltage, high impedance.
When the MPPT tries to find the best operating point, the solar panel voltage may drop into the high‑impedance region, which can make the control loop unstable.
In this design, the solar panel input is operating at high impedance (<12 V), so an R‑C network (R4 and C1) is added to stabilize the control loop when sunlight changes.
For low wattage solar panels, a high capacitance (100 µF to 1000 µF) for C1 is recommended to keep the MPPT stable and ensure reliable performance.
Related Article:
How Does the LTC4416 Enable Smart Power Switching in a Single‑Board System?
How Does the Smart Power Bank’s Design Manage Multiple Power Sources?
Why Choose a Single‑Board Smart Power Bank for Your Next Project?
Applicable Part Numbers
| DigiKey Part Number | Manufacturer Part Number |
|---|---|
| 505-LTC3115EDHD-1#PBF-ND | LTC3115EDHD-1#PBF |
| 505-LTC3115EDHD-1#TRPBFTR-ND,505-LTC3115EDHD-1#TRPBFCT-ND,505-LTC3115EDHD-1#TRPBFDKR-ND | LTC3115EDHD-1#TRPBF |
| LTC3115EFE-1#TRPBFTR-ND,LTC3115EFE-1#TRPBFCT-ND,LTC3115EFE-1#TRPBFDKR-ND | LTC3115EFE-1#TRPBF |
| 505-LTC3115EFE-1#PBF-ND | LTC3115EFE-1#PBF |
| 505-LTC3115IDHD-1#TRPBFTR-ND,505-LTC3115IDHD-1#TRPBFCT-ND,505-LTC3115IDHD-1#TRPBFDKR-ND | LTC3115IDHD-1#TRPBF |
| 505-LTC3115IDHD-1#PBF-ND | LTC3115IDHD-1#PBF |
| 505-LTC3115IFE-1#PBF-ND | LTC3115IFE-1#PBF |
| 505-LTC3115EDHD-2#PBF-ND | LTC3115EDHD-2#PBF |
| 505-LTC3115EFE-2#PBF-ND | LTC3115EFE-2#PBF |
| 505-LTC3115IFE-1#TRPBFTR-ND,505-LTC3115IFE-1#TRPBFCT-ND,505-LTC3115IFE-1#TRPBFDKR-ND | LTC3115IFE-1#TRPBF |
| LTC3115IFE-2#PBF-ND | LTC3115IFE-2#PBF |
| 505-LTC3115HFE-1#PBF-ND | LTC3115HFE-1#PBF |
| 505-LTC3115IDHD-2#PBF-ND | LTC3115IDHD-2#PBF |
| 161-LTC3115MPFE-1#PBF-ND | LTC3115MPFE-1#PBF |
| LTC3115MPFE-2#PBF-ND | LTC3115MPFE-2#PBF |
| 505-LTC3115EDHD-2#TRPBFTR-ND | LTC3115EDHD-2#TRPBF |
| 505-LTC3115HFE-2#PBF-ND | LTC3115HFE-2#PBF |
| 161-LTC3115IDHD-1#WPBF-ND | LTC3115IDHD-1#WPBF |
| 505-LTC3115EFE-2#TRPBFTR-ND | LTC3115EFE-2#TRPBF |
| 161-LTC3115IDHD-1#WTRPBFTR-ND | LTC3115IDHD-1#WTRPBF |
| LTC3115IFE-2#TRPBF-ND | LTC3115IFE-2#TRPBF |
| LTC3115HFE-1#TRPBF-ND | LTC3115HFE-1#TRPBF |
| LTC3115HFE-2#TRPBF-ND | LTC3115HFE-2#TRPBF |
| LTC3115IDHD-2#TRPBF-ND | LTC3115IDHD-2#TRPBF |
| LTC3115MPFE-1#TRPBF-ND | LTC3115MPFE-1#TRPBF |
| 505-LTC4162EUFD-LAD#TRPBFTR-ND,505-LTC4162EUFD-LAD#TRPBFCT-ND,505-LTC4162EUFD-LAD#TRPBFDKR-ND | LTC4162EUFD-LAD#TRPBF |
| 505-LTC4162EUFD-FAD#PBF-ND | LTC4162EUFD-FAD#PBF |
| 505-LTC4162EUFD-LAD#PBF-ND | LTC4162EUFD-LAD#PBF |
| 505-LTC4162EUFD-L42#TRPBFTR-ND,505-LTC4162EUFD-L42#TRPBFCT-ND,505-LTC4162EUFD-L42#TRPBFDKR-ND | LTC4162EUFD-L42#TRPBF |
| 505-LTC4162EUFD-SAD#PBF-ND | LTC4162EUFD-SAD#PBF |
| 505-LTC4162EUFD-SADM#PBF-ND | LTC4162EUFD-SADM#PBF |
| 505-LTC4162EUFD-LADM#PBF-ND | LTC4162EUFD-LADM#PBF |
| 505-LTC4162IUFD-FAD#PBF-ND | LTC4162IUFD-FAD#PBF |
| 505-LTC4162IUFD-SADM#PBF-ND | LTC4162IUFD-SADM#PBF |
| 505-LTC4162IUFD-LAD#PBF-ND | LTC4162IUFD-LAD#PBF |
| 505-LTC4162EUFD-L42#PBF-ND | LTC4162EUFD-L42#PBF |
| 505-LTC4162EUFD-L42M#PBF-ND | LTC4162EUFD-L42M#PBF |
| 505-LTC4162EUFD-L41#PBF-ND | LTC4162EUFD-L41#PBF |
| LTC4162EUFD-SSTM#PBF-ND | LTC4162EUFD-SSTM#PBF |
| LTC4162IUFD-FADM#PBF-ND | LTC4162IUFD-FADM#PBF |
| LTC4162IUFD-SSTM#PBF-ND | LTC4162IUFD-SSTM#PBF |
| LTC4162EUFD-L40#PBF-ND | LTC4162EUFD-L40#PBF |
| LTC4162EUFD-L40M#PBF-ND | LTC4162EUFD-L40M#PBF |
| LTC4162EUFD-FFSM#PBF-ND | LTC4162EUFD-FFSM#PBF |
| LTC4162EUFD-L41M#PBF-ND | LTC4162EUFD-L41M#PBF |
| 505-LTC4162EUFD-FSTM#PBF-ND | LTC4162EUFD-FSTM#PBF |
| LTC4162EUFD-FST#PBF-ND | LTC4162EUFD-FST#PBF |
| LTC4162EUFD-FFS#PBF-ND | LTC4162EUFD-FFS#PBF |
| LTC4162IUFD-SST#PBF-ND | LTC4162IUFD-SST#PBF |
| 505-LTC4162IUFD-L42#PBF-ND | LTC4162IUFD-L42#PBF |
| LTC4162IUFD-L40#PBF-ND | LTC4162IUFD-L40#PBF |
| LTC4162IUFD-L40M#PBF-ND | LTC4162IUFD-L40M#PBF |
| LTC4162IUFD-FFSM#PBF-ND | LTC4162IUFD-FFSM#PBF |
| LTC4162IUFD-L41M#PBF-ND | LTC4162IUFD-L41M#PBF |
| 505-LTC4162IUFD-L41#PBF-ND | LTC4162IUFD-L41#PBF |
| LTC4162IUFD-FSTM#PBF-ND | LTC4162IUFD-FSTM#PBF |
| 505-LTC4162IUFD-L42M#PBF-ND | LTC4162IUFD-L42M#PBF |
| LTC4162IUFD-FFS#PBF-ND | LTC4162IUFD-FFS#PBF |
| 505-LTC4162IUFD-LAD#TRPBFTR-ND | LTC4162IUFD-LAD#TRPBF |
| 505-LTC4162EUFD-FADM#TRPBFTR-ND,505-LTC4162EUFD-FADM#TRPBFCT-ND,505-LTC4162EUFD-FADM#TRPBFDKR-ND | LTC4162EUFD-FADM#TRPBF |
| 505-LTC4162IUFD-SAD#PBF-ND | LTC4162IUFD-SAD#PBF |
| 505-LTC4162IUFD-LADM#PBF-ND | LTC4162IUFD-LADM#PBF |
| LTC4162IUFD-FST#PBF-ND | LTC4162IUFD-FST#PBF |
| LTC4162EUFD-FADM#PBF-ND | LTC4162EUFD-FADM#PBF |
| LTC4162EUFD-SST#PBF-ND | LTC4162EUFD-SST#PBF |
| LTC4162EUFD-FAD#TRPBF-ND | LTC4162EUFD-FAD#TRPBF |
| LTC4162EUFD-FFS#TRPBF-ND | LTC4162EUFD-FFS#TRPBF |
| LTC4162EUFD-FFSM#TRPBF-ND | LTC4162EUFD-FFSM#TRPBF |
| LTC4162EUFD-FST#TRPBF-ND | LTC4162EUFD-FST#TRPBF |
| LTC4162EUFD-FSTM#TRPBF-ND | LTC4162EUFD-FSTM#TRPBF |
| LTC4162EUFD-L40#TRPBF-ND | LTC4162EUFD-L40#TRPBF |
| LTC4162EUFD-L40M#TRPBF-ND | LTC4162EUFD-L40M#TRPBF |
| LTC4162EUFD-L41#TRPBF-ND | LTC4162EUFD-L41#TRPBF |
| LTC4162EUFD-L41M#TRPBF-ND | LTC4162EUFD-L41M#TRPBF |
| LTC4162EUFD-L42M#TRPBF-ND | LTC4162EUFD-L42M#TRPBF |
| LTC4162EUFD-LADM#TRPBF-ND | LTC4162EUFD-LADM#TRPBF |
| LTC4162EUFD-SAD#TRPBF-ND | LTC4162EUFD-SAD#TRPBF |
| LTC4162EUFD-SADM#TRPBF-ND | LTC4162EUFD-SADM#TRPBF |
| LTC4162EUFD-SST#TRPBF-ND | LTC4162EUFD-SST#TRPBF |
| LTC4162EUFD-SSTM#TRPBF-ND | LTC4162EUFD-SSTM#TRPBF |
| LTC4162IUFD-FAD#TRPBF-ND | LTC4162IUFD-FAD#TRPBF |
| LTC4162IUFD-FADM#TRPBF-ND | LTC4162IUFD-FADM#TRPBF |
| LTC4162IUFD-FFS#TRPBF-ND | LTC4162IUFD-FFS#TRPBF |
| LTC4162IUFD-FFSM#TRPBF-ND | LTC4162IUFD-FFSM#TRPBF |
| LTC4162IUFD-FST#TRPBF-ND | LTC4162IUFD-FST#TRPBF |
| LTC4162IUFD-FSTM#TRPBF-ND | LTC4162IUFD-FSTM#TRPBF |
| LTC4162IUFD-L40#TRPBF-ND | LTC4162IUFD-L40#TRPBF |
| LTC4162IUFD-L40M#TRPBF-ND | LTC4162IUFD-L40M#TRPBF |
| LTC4162IUFD-L41#TRPBF-ND | LTC4162IUFD-L41#TRPBF |
| LTC4162IUFD-L41M#TRPBF-ND | LTC4162IUFD-L41M#TRPBF |
| LTC4162IUFD-L42#TRPBF-ND | LTC4162IUFD-L42#TRPBF |
| LTC4162IUFD-L42M#TRPBF-ND | LTC4162IUFD-L42M#TRPBF |
| LTC4162IUFD-LADM#TRPBF-ND | LTC4162IUFD-LADM#TRPBF |
| LTC4162IUFD-SAD#TRPBF-ND | LTC4162IUFD-SAD#TRPBF |
| LTC4162IUFD-SADM#TRPBF-ND | LTC4162IUFD-SADM#TRPBF |
| LTC4162IUFD-SST#TRPBF-ND | LTC4162IUFD-SST#TRPBF |
| LTC4162IUFD-SSTM#TRPBF-ND | LTC4162IUFD-SSTM#TRPBF |
| 505-LTC4416EMS-1#PBF-ND | LTC4416EMS-1#PBF |
| 505-LTC4416EMS#TRPBFTR-ND,505-LTC4416EMS#TRPBFCT-ND,505-LTC4416EMS#TRPBFDKR-ND | LTC4416EMS#TRPBF |
| 505-LTC4416EMS#PBF-ND | LTC4416EMS#PBF |
| 505-LTC4416IMS#PBF-ND | LTC4416IMS#PBF |
| 505-LTC4416IMS-1#PBF-ND | LTC4416IMS-1#PBF |
| 505-LTC4416IMS#TRPBFTR-ND,505-LTC4416IMS#TRPBFCT-ND,505-LTC4416IMS#TRPBFDKR-ND | LTC4416IMS#TRPBF |
| LTC4416EMS-1#TRPBFTR-ND,LTC4416EMS-1#TRPBFCT-ND,LTC4416EMS-1#TRPBFDKR-ND | LTC4416EMS-1#TRPBF |
| 505-LTC4416IMS-1#TRPBFTR-ND | LTC4416IMS-1#TRPBF |
| 161-LTC4416IMS-1-ND | LTC4416IMS-1 |