MP5403

– CONFIGURABLE 2.7V-6V MINI PMIC WITH DUAL 2.5A/3.5A BUCK,

ONE LOAD SWITCH, AND INPUT POWER SUPERVISORY

MP5403 Rev. 1.0

www.MonolithicPower.com

20

9/20/2016

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Output Capacitor Selection

The output capacitor limits the output voltage

ripple and ensures a stable regulation loop.

Select an output capacitor with low impedance

at

the

switching

frequency.

Use

ceramic

capacitors with X5R or X7R dielectrics. Using

an electrolytic capacitor may result in additional

output voltage ripple, thermal issues, and

require additional care in selecting the feedback

resistor (R1) due to the large ESR. For most

applications, a 22µF capacitor is sufficient.

PCB Layout Guidelines

Efficient PCB layout of the switching power

supplies is critical for stable operation. If the

layout is not done carefully, regarding the high

switching frequency converter especially, the

regulator

could

show

poor

line

or

load

regulation and stability issues. For best results,

refer to Figure 6 and follow the guideline below.

1. Place the input capacitor as close to the IC

pins as possible for the high-speed step-

down regulator to provide clean control

voltage.

1

1

1

2

VIN1

VIN2

GND

VOUT1

VOUT2

GND

VIN3

VOUT3

GND

GND

C1A

C1B

C2

C3

C4

C5

C6

L1

L2

C7

R1

R2

R3

R4

EN1

EN2

EN3

PG3

PG2

PG1

Top Layer

GND

VIN3

Vout1 Sense

Vout2 Sense

Bottom Layer

Figure 6: Recommended PCB Layout