DEMO MANUAL DC1587 LTC3105EDD: Step-Up DC/DC Converter with Power Point Control and LDO Regulator DESCRIPTION Demonstration circuit 1587A is a boost converter op- power good output and external power good supply input, timized for relatively high impedance, very low voltage shutdown input, and provisions for external MPPC resistor input power sources. It allows a user to quickly evaluate and MPPC diode input. the LTC3105 boost converter and LDO regulator. Capable This demonstration board is especially designed for low of operating with an input voltage as low as 250mV and power solar cell applications. The LTC3105 data sheet as high as 5V, the circuit features maximum power point gives a complete description of the part, operation and control (MPPC). Jumpers on the circuit board allow the application information. The data sheet must be read in user to select several MPPC voltages, three boost output conjunction with this demo manual. voltages and three LDO regulator output voltages. Also Design les for this circuit board are available at included are jumpers for shutdown and for selecting an DEMO MANUAL DC1587 QUICK START PROCEDURE 2. With the power off, connect a low voltage adjustable and current as the input voltage begins to drop due power supply and three voltmeters as shown in Figure1 to the input power source current limitations. Without (ammeters are optional). Switch the power supply on MPPC, a converter would pull the input power source and adjust the voltage to approximately 450mV, and down to near 0V, resulting in near zero output power. move the JP5 jumper to the ON position. With no load MPPC is especially useful with power sources that have resistor on either output, verify that the BOOST and LDO relatively high or variable source impedances such as output voltages are within the speci cations shown in solar cells and other energy harvesting devices. The Table 1. Increase the input voltage to 1.5V and connect following exercise is to illustrate the MPPC function. suitable load resistors to the output terminals to verify To demonstrate the MPPC function, place a 10, 1W the output voltages under load. The maximum Boost resistor in series with the demo board input terminal output current is dependant on V and the maximum IN (V ) to simulate a high impedance power source. Move IN LDO output current is 6mA jumper JP2 (MPPC) to the 2V position and jumpers JP1 Maximum power point control (MPPC) prevents the and JP3 to the 5V and 3V positions respectively and converter from pulling the input supply voltage down connect voltmeters to measure V and boost V . IN OUT below a preset voltage level when the maximum input With the power supply set to 3.5V, apply voltage to the supply current is reached. The converter does this by input. With an adjustable load on the boost output, dynamically reducing the converters output voltage begin increasing the load on the 5V output. Figure 1. Proper Measurement Equipment Setup dc1587f 2