Solar cell battery charging IC for mobile phones

ST Microelectronics has released new battery charging IC using valuable source of solar energy in small strips of solar cells seen in applications of the front panels of small portable consumer, healthcare and security devices. The IC will increase charging efficiency either indoor or outdoor, using the sun's radiated energy, enabling longer mobile equipment runtime and avoiding an unexpected lack of power when a mains connection is not available.

ST's SPV1040 contains step-up DC-DC converter for solar battery charger to obtain maximum possible energy from solar cells using Maximum Power Point Tracking (MPPT) Technique. It can be connected to strips of even just a few cells, allowing use in products such as portable healthcare devices, watches, calculators, wireless headsets, toys, or mobile phones. The battery charger and MPPT technology can also be used in equipment such as sensors and security cameras.

The MPPT algorithm embedded in SPV1040 to adjust charger's input impedence for matching with solar cell and to maximize energy transfer to battery. If MPPT has not enclosed then their will be a reduce in energy harvested due to temperature, ageing, dirt.

Major features of SPV1040:
Input-voltage range: 0.3V to 5.5V
Integrated low-loss synchronous rectifier and power switch
Up to 95% efficiency
Shutdown pin to aid system-level power management
Thermal shutdown and protection circuitry to improve battery and overall system safety