PCB layout guidelines

AN2837

10/12

In polarity-inverting mode the ST1S03 is capable of supplying more output current, as

shown in Figure 11 and Figure 12.

With a 12 V input voltage (Figure 12), the ST1S03 should be able to provide up to 1.3 A of

output current with good stability and performance. It is important not to exceed the

maximum switching current limitation of 2.5 A that flows in the inductor. Choosing a good

inductor, in terms of current capability and low series resistance, can help to improve

efficiency.

Figure 11.

Switch Voltage, 5V/div

Inductor Current, 500mA/div

Switch Voltage, 5V/div

Inductor Current, 500mA/div

Figure 12.

Switch Voltage, 5V/div

Inductor Current, 500mA/div

Switch Voltage, 5V/div

Inductor Current, 500mA/div