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dc1587f

DEMO MANUAL DC1587

QUICK START PROCEDURE

2. With the power off, connect a low voltage adjustable

power supply and three voltmeters as shown in Figure 1

(ammeters are optional). Switch the power supply on

and adjust the voltage to approximately 450mV, and

move the JP5 jumper to the ON position. With no load

resistor on either output, verify that the BOOST and LDO

output voltages are within the specifications shown in

Table 1. Increase the input voltage to 1.5V and connect

suitable load resistors to the output terminals to verify

the output voltages under load. The maximum Boost

LDO output current is 6mA

Maximum power point control (MPPC) prevents the

converter from pulling the input supply voltage down

below a preset voltage level when the maximum input

supply current is reached. The converter does this by

dynamically reducing the converter’s output voltage

and current as the input voltage begins to drop due

to the input power source current limitations. Without

MPPC, a converter would pull the input power source

down to near 0V, resulting in near zero output power.

MPPC is especially useful with power sources that have

relatively high or variable source impedances such as

solar cells and other energy harvesting devices. The

following exercise is to illustrate the MPPC function.

To demonstrate the MPPC function, place a 10Ω, 1W

resistor in series with the demo board input terminal

jumper JP2 (MPPC) to the 2V position and jumpers JP1

and JP3 to the 5V and 3V positions respectively and

With the power supply set to 3.5V, apply voltage to the

input. With an adjustable load on the boost output,

begin increasing the load on the 5V output.

Figure 1. Proper Measurement Equipment Setup