Table 8-2. Recommended Component Values (continued)

OUTPUT

VOLTAGE

(V)

R1 (kΩ)

R2 (kΩ)

Min L(uH)

TYP L (uH)

Max L(uH)

Min

Cout(uF)

Typ Cout(uF)

Max

Cout(uF)

Typ CFF(pF)

5

220.0

30.0

3.3

4.7

6.8

22

44

110

18

7

320.0

30.0

5.6

6.8

8.2

22

44

110

18

The inductor peak-to-peak ripple current, peak current and RMS current are calculated using Equation 5,

Equation 6, and Equation 7. The inductor saturation current rating must be greater than the calculated peak

current and the RMS or heating current rating must be greater than the calculated RMS current.

IN(MAX)

OUT

OUT

P P

IN(MAX)

O

SW

V

V

V

Il

V

L

f

u

u

(5)

P P

PEAK

O

Il

Il

I

2

(6)

2

2

LO(RMS)

O

P P

1

I

I

Il

12

(7)

For this design example, the calculated peak current is 3.68 A and the calculated RMS current is 3.03 A. The

inductor used is a WE 74437349022.

The capacitor value and ESR determines the amount of output voltage ripple. The TPS563203 are intended for

use with ceramic or other low ESR capacitors. TI recommends to use 2 × 22 µF output cap. Use Equation 8 to

determine the required RMS current rating for the output capacitor.

OUT

IN

OUT

CO(RMS)

IN

O

SW

V

V

V

I

12

V

L

f

u

u

u

u

(8)

For this design two MuRata GRM21BR61A226ME44L 22-µF output capacitors are used. The typical ESR is 2

mΩ each. The calculated RMS current is 0.286 A and each output capacitor is rated for 4 A.

8.2.2.3 Input Capacitor Selection

The TPS563203 require an input decoupling capacitor and a bulk capacitor is needed depending on the

application. TI recommends a ceramic capacitor over 10 µF for the decoupling capacitor. An additional 0.1-µF

capacitor (C3) from pin 3 to ground is optional to provide additional high frequency filtering. The capacitor

voltage rating must be greater than the maximum input voltage.

8.2.2.4 Bootstrap Capacitor Selection

A 0.1-µF ceramic capacitor must be connected between the BST to SW pin for proper operation. TI recommends

to use a ceramic capacitor.

www.ti.com

TPS563203, TPS563206

SLUSEZ4 – MARCH 2023

Copyright © 2023 Texas Instruments Incorporated

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