ACE722G

5V 2.0A, 1.3MHz

Synchronous Buck Converter

VER 1.1

11

Output Capacitor and Inductor Selection

Follow the below table for Inductor and Output cap selection:

1.2V

1.5V

1.8V

2.5V

3.3V

33

F

33

F

22

F

22

F

10

F

L

1.5

H

1.5

H

2.2

H

3.3

H

4.7

H

If much smaller values are used, inductor current rises, and a larger output capacitance may be required

to suppress output ripple. Larger values than LIDEAL can be used to obtain higher output current, but

typically with larger inductor size.

Application Information

Layout is critical to achieve clean and stable operation. The switching power stage requires particular

attention. Follow these guidelines for good PC board layout:

(1) Place decoupling capacitors as close to the IC as possible

(2) Connect input and output capacitors to the same power ground node with a star ground configuration

then to IC ground.

(3) Keep the high-current paths as short and wide as possible. Keep the path of switching current

(C1 to IN and C1 to GND) short. Avoid vias in the switching paths.

(4) If possible, connect IN, SW, and GND separately to a large copper area to help cool the IC to further

improve efficiency and long-term reliability.

(5) Ensure all feedback connections are short and direct. Place the feedback resistors as close to the IC

as possible.

(6) Route high-speed switching nodes away from sensitive analog area.