RT9527 Datasheet, PDF (12/14 Pages) Richtek Technology Corporation – Single Cell Li-Ion Battery Charger with Adjustable Charging Current for Portable Applications

RT9527
0.9
Four-Layer PCB
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0.0
0
25
50
75
100
125
Ambient Temperature (°C)
Figure 1. Derating Curve of Maximum Power Dissipation
Layout Considerations
The RT9527 is a fully integrated low cost single cell Li-Ion
battery charger ideal for portable applications. Careful PCB
layout is necessary. For best performance, place all
peripheral components as close to the IC as possible. A
short connection is highly recommended. The following
guidelines must be strictly followed when designing a PCB
layout for the RT9527.
` Input and output capacitor should be placed close to IC
and connected to ground plane. The trace of input in the
PCB should be placed far away from the sensitive devices
and shielded by the ground.
` The GND and exposed pad should be connected to a
strong ground plane for heat sinking and noise protection.
` The connection of R_ISET should be isolated from other
noisy traces. A short wire is recommended to prevent
EMI and noise coupling.
Place C_IN near the IC to
improve performance.
Connect the Exposed
Pad to a ground plane.
GND
VIN
C_IN
C_OUT
R2 R1 _{VIN 1}
8 BAT
R_T1
PGOOD 2
7 TS
CHG 3
GND 4
6 TIMER
9 _{5 ISET}
R_T2
GND
R_ISET
C_TIMER
GND should be connected to a
strong ground plane for heat
sinking and noise protection.
The R_ISET connection copper area
should be minimized and kept far
away from noise sources.
Figure 2. PCB Layout Guide
Copyright ©2012 Richtek Technology Corporation. All rights reserved.
www.richtek.com
12
is a registered trademark of Richtek Technology Corporation.
DS9527-00 May 2012