9

RT8525

DS8525-01 March 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 RT8525.

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.

to IC as 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

Figure 4. Derating Curve of Maximum Power Dissipation

DRV

PGND

ISW

EN

OOVP

FB

FAULT

VDC

VIN

COMP

SS

FSW

AGND

PWMI

2

3

4

5

8

7

6

14

13

12

11

10

9

PGND

M1

D1

L1

AGND

PGND

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.

AGND is suggested

that connect to PGND

from the sense resistor

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

0

25

50

75

100

125

Ambient Temperature (°C)

Single-Layer PCB