Texas Instruments recommends a 4-layer PCB with a solid ground plane and a separate power plane for the DC-DC converter. The input and output capacitors should be placed close to the IC, and the feedback resistors should be placed close to the FB pin.
The inductor selection depends on the output current, switching frequency, and output voltage. A good starting point is to use an inductor with a value between 1.5uH to 3.3uH, and a saturation current rating above the maximum output current. The inductor should also have a low DCR (DC resistance) to minimize power loss.
The DCP020509U can handle input voltages up to 18V, but it's recommended to keep the input voltage below 15V to ensure reliable operation and minimize power loss.
The output voltage of the DCP020509U can be adjusted by changing the feedback resistors (R1 and R2) according to the formula: Vout = 0.8V * (1 + R2/R1). The resistors should be chosen to ensure a stable output voltage and minimize output voltage ripple.
The DCP020509U has a thermal derating of -1.5%/°C above 25°C. This means that the maximum output current will decrease as the ambient temperature increases above 25°C.
DCP020509U datasheet
by Texas Instruments
