TPS53313

VIN

SW

Output All MLCCs

UDG-11254

PG

FB

COMP

BP7

AGND

RT/SYNC

EN

MODE/SS

VBST

PowerPad

PGND

BP3

EN

PGOOD

(

)

IN

OUT

OUT

L(ripple)

SW

IN

V

V

V

1

I

L f

V

-

´

=

´

´

RIPPLE

RIPPLE(C)

RIPPLE(ESR)

RIPPLE(ESL)

V

V

V

V

=

+

+

TPS53313

www.ti.com

SLUSAS8

– DECEMBER 2011

APPLICATION INFORMATION

DESIGN EXAMPLE

The following example illustrates the design process and component selection for a single-output synchronous

buck converter using the TPS53313. The design example schematic of a is shown in Figure 13. The specification

of the converter is listed in Table 3.

Table 3. Design Example Converter Specifications

PARAMETER

TEST CONDITION

MIN

TYP

MAX

UNIT

Input voltage

10.8

12.0

13.2

V

Output voltage

1.2

V

Output ripple

V

Output current

6

A

Switching frequency

600

kHz

Figure 13. Typical 12-V input Application Circuit Diagram

Output Inductor Selection

The inductance value should be determined to give the ripple current of approximately 20% to 40% of maximum

output current. The inductor ripple current is determined by

(1)

The inductor also requires a low DCR to achieve good efficiency, as well as enough room above peak inductor

current before saturation.

Output Capacitor Selection

The output capacitor selection is determined by output ripple and transient requirement. When operating in CCM,

the output ripple has three components:

(2)

Copyright

© 2011, Texas Instruments Incorporated

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