LTC3105 - 400mA Step-Up DC/DC Converter with Maximum Power Point Control and 250mV Start-Up
DC/DC converter ideal for harvesting and managing surplus energy from low input voltage sources such as a small solar cell. The step-up topology operates from input voltages as low as 250mV.
Operation The LTC3105 is a high efficiency step-up DC/DC converter that can operate from input voltages as low as 225mV. A 250mV start-up capability and integrated maximum power point controller (MPPC) enable operation directly from low voltage, high impedance alternative power sources such as photovoltaic cells, TEGs (thermoelectric generators) and fuel cells. A user programmable MPPC set point maximizes the energy that can be extracted from any power source.
This converter has two power outputs:
1. A LDO voltage regulator with selectable output.
2. Vout with selectable voltage.
Output voltage level, LDO voltage and MPPT voltage are selected on the three solder jumpers.
In the above example, the selected Vout is 5 volts. To change selection, the trace in the solder jumper is cut and a solder jumper with a new selected voltage is soldered.
Default voltages are: 5V for Vout, 3.3V for VLDO and 0.4V for MPPT.
There are also two control signals:
1. PGood indicator signals the host microcontroller that the main output voltage is within regulation.
2. /SHDN is an input to the converter which is used to turn the outputs off.
Solar Powered Battery/Supercapacitor Chargers
Remote Industrial Sensors
Low Power Wireless Transmitters
Cell Phone, MP3, PMP and GPS Accessory Chargers
Features Low Start-Up Voltage: 250mV
Maximum Power Point Control
Wide VIN Range: 225mV to 5V
6mA LDO Regulator
Burst Mode® Operation: IQ = 24μA
Output Disconnect and Inrush Current Limiting
VIN > VOUT Operation
Antiringing Control, Soft Start, Automatic Power Adjust
Power Good Indicator
52mm x 42mm