AN2093 - APPLICATION NOTE

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Table 1: Suggested Components

Even if we suggest a particular brand, the device is stable with all the other brands in the market.

Figure 3: Board Layout

Due to the high switching frequency and peak current, it is important to optimize the application

environment reducing the length of the PCB traces and placing all the external component near the

device.

Figure 3 shows the recommended board layout.

It is very important to connect the two input pins 4mm far from the device, it avoids noise inside the control

circuit, coming from the power switch. A great importance has the ground metal. It is mandatory to start all

the GND patterns from the same point, in this case we can avoid the noise due to the drop on the power

GND metal.

The minimum input capacitor is 4.7µF ceramic X7R or X5R, this value can be increased without any

limitation.

The minimum suggested output capacitor is 22µF X7R or X5R. It is possible to obtain the minimum output

capacitor value connecting several capacitors in parallel, in this case the ESR is minimized and the output

ripple is reduced. Even if the device has excellent dynamic performances it is possible to improve the load

transient just increasing the output capacitor value.

Material

Brand

P/N

C1

4.7µF

Ceramic

TDK

C3216 X7R 1C475K

C2

22µF

Ceramic

TDK

C3225 X7R 1C 226M

L1

3.3µH

TDK

RLF7030T-3R3M4R1

D

-

-

ST

STPS2L30A