AP3595

Document number: DS36749 Rev. 1 - 2

16 of 23

www.diodes.com

January 2014

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AP3595

A Product Line of

Diodes Incorporated

Calculate the C2 by the equation:

75

.

0

2

2

1

2











LC

f

R

C



ESR

P

f

f



1

Calculate the C1 by the following equation:

1

2

2

2

2

1













ESR

f

C

R

C

C



amplifier.

LC

Z

SW

P

f

f

f

f







2

2

5

.

0

Combine the two equations will get the following component calculations:

1

2

1

3







LC

SW

f

f

R

R

SW

f

R

C







3

1

3



Figure 10.Converter Gain and Frequency

14. Output Inductor Selection

The duty cycle (D) of a buck converter is the function of the input voltage and output voltage. Once an output voltage is fixed, it can be written as:

IN

OUT

V

V

D

/



For two-phase converter, the inductor value (L)

response. Higher inductor value

reduces the output capacitors’ ripple current and induces lower output ripple voltage. The ripple current can be

approximated by:

IN

OUT

SW

OUT

IN

P

P

V

V

L

f

V

V

I













2