ADP5303

Data Sheet

Rev. B | Page 16 of 21

APPLICATIONS INFORMATION

This section describes the external components selection for the

ADP5303. A typical application circuit is shown in Figure 40.

SW

PGND

FB

PVIN

10µF

MLCC

SYNC/

MODE

EN

AGND

AGND

VID

2.15V TO 6.50V

2.2µH

10µF

MLCC

ADP5303

(WLFCSP-9)

VINOK

R2

1MΩ

R1

19.6kΩ

Figure 40. Typical Application Circuit

EXTERNAL COMPONENT SELECTION

The ADP5303 is optimized for operation with a 2.2 μH

inductor and 10 μF output capacitors for various output

voltages using the closed-loop compensation and adaptive slope

compensation circuits. The selection of components depends

on the efficiency, the load current transient, and other application

requirements. The trade-offs among performance parameters,

such as efficiency and transient response, are made by varying

the choice of external components.

SELECTING THE INDUCTOR

The high frequency switching of the ADP5303 allows the use of

small surface-mount power inductors. The dc resistance (DCR)

value of the selected inductor affects efficiency. In addition, it is

recommended to select a multilayer inductor rather than a

magnetic iron inductor because the high switching frequency

increases the core temperature rise and enlarges the core loss.

A minimum requirement of the dc current rating of the inductor

is for it to be equal to the maximum load current plus half of the





















×

×

=

∆

SW

IN

OUT

OUT

L

f

L

V

V

V

I

–

1











 ∆

+

=

2

)

(

L

MAX

LOAD

PK

I

I

I

Use the inductor series from different vendors shown in Table 6.

OUTPUT CAPACITOR

Output capacitance is required to minimize the voltage overshoot,

the voltage undershoot, and the ripple voltage present on the

output. Capacitors with low equivalent series resistance (ESR)

values produce the lowest output ripple. Furthermore, use

capacitors such as X5R and X7R dielectric capacitors. Do not use

Y5V and Z5U capacitors, which are unsuitable choices due to

their large capacitance variation over temperature and their dc

bias voltage changes. Because ESR is important, select the

capacitor using the following equation:

L

RIPPLE

COUT

I

V

ESR

Δ

≤

where:

Increasing the output capacitor value has no effect on stability

and may reduce output ripple and enhance load transient response.

When choosing the output capacitor value, it is important to

account for the loss of capacitance due to output voltage dc bias.

Choose the capacitor series from the different vendors shown in

Table 7.

Table 6. Recommended Inductors

Vendor

Model

Inductance (μH)

Dimensions (mm)

DCR (mΩ)

TDK

MLP2016V2R2MT0S1

2.2

2.0 × 1.6 × 0.85

280

1.0

Würth

74479889222

2.2

2.5 × 2.0 × 1.2

250

1.7

Coilcraft

LPS3314-222MR

2.2

3.3 × 3.3 × 1.3

100

1.5

1

Table 7. Input and Output Capacitors

Vendor

Model

Capacitance (μF)

Size

Murata

GRM188D71A106MA73

10

0603

Murata

GRM21BR71A106KE51

10

0805

Murata

GRM31CR71A106KA01

10

1206