RT8272
SW
GND
V
IN
C
SS
CB
The parallel distance between
C
IN
COMP and FB traces must be
as short as possible.
Input capacitor must be placed
as close to the IC as possible.
BOOT
VIN
8
SS
2
3
4
7
6
5
EN
C
C
GND
D1
SW
COMP
C
OUT
GND
FB
C
P
R
C
L
The output capacitor must be
placed near the RT8272.
V
OUT
GND
SW should be connected to inductor by
wide and short trace. Keep sensitive
components away from this trace.
V
OUT
The resistor divider must be connected
as close to the device as possible.
Figure 4. PCB Layout Guide
Table 2. Suggested Inductors for Typical Application Circuit
Component Supplier
TDK
Series
Inductance (mH)
DCR (mW)
Current Rating (A) Dimensions (mm)
RLF7030
NR8040
GSSR2
4.7
4.7
4.7
31
18
18
3.5
4.7
5.7
7.3 x 6.8 x 3.2
8 x 8 x 4
TAIYO YUDEN
GOTERND
10 x 10 x 3.8
Table 3. Suggested Capacitors for CIN and COUT
Component Supplier
MURATA
Part No.
Capacitance (mF)
Case Size
1206
GRM31CR61E106K
C3225X5R1E106K
TMK316BJ106ML
GRM31CR60J476M
C3225X5R0J476M
EMK325BJ476MM
10
10
10
47
47
47
TDK
1206
TAIYO YUDEN
MURATA
1206
1206
1210
TDK
1210
TAIYO YUDEN
Table 4. Suggested Diode
Component Supplier
DIODES
Series
B330A
B340
V
(V)
I
(A)
Package
DO-214AC
DO-214AB
DO-214AB
DO-214AB
RRM
OUT
30
3
3
3
3
40
30
40
DIODES
PANJIT
SK33
SK34
PANJIT
DS8272-02 March 2011
www.richtek.com
11
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
