11

RT8525D

DS8525D-00 June 2012

www.richtek.com

©

Copyright 2012 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

Layout Considerations

PCB layout is very important for designing switching power

converter circuits. The following layout guides should be

strictly followed for best performance of the RT8525D.

must be placed as close as possible to reduce current

loop. The PCB trace between power components must

be as short and wide as possible.

possible. The trace should be kept away from the power

loops and shielded with a ground trace to prevent any

noise coupling.

The compensation circuit should be kept away from

the power loops and should be shielded with a ground

trace to prevent any noise coupling. Place the

compensation components to the COMP pin as close

Figure 5. PCB Layout Guide

The compensation circuit should be

kept away from the power loops and

should be shielded with a ground

trace to prevent any noise coupling.

Place the power components as Close as

possible. The traces should be wide and

short especially for the high current loop.

The feedback voltage divider resistors must near the

feedback pin. The divider center trace must be shorter

and avoid the trace near any switching nodes.

VDC

VIN

FSW

SS

EN

DRV

GND

OVP

ISW

COMP

FAULT

FB

11

10

9

1

2

3

4

5

12

67

8

13

M1

GND

L1

D1

GND

GND

Figure 4. Derating Curve of Maximum Power Dissipation

0.00

0.15

0.30

0.45

0.60

0.75

0.90

1.05

1.20

1.35

1.50

1.65

1.80

0

255075

100

125

Ambient Temperature (°C)

Four-Layer PCB

resistance,

designer to see the effect of rising ambient temperature

on the maximum power dissipation.