RT7257J
Typical Application Circuit
1
3
V
2
IN
VIN
BOOT
RT7257J
4.5V to 18V
C
C
BOOT
0.1µF
IN
L
10µF x 2
10µH
V
3.3V
OUT
SW
Chip Enable
R1
7
8
EN
SS
75k
C
OUT
22µF x 2
5
6
FB
C
C
C
0.1µF
R
SS
C
R2
4.7nF
12k
24k
4, 9 (Exposed Pad)
COMP
GND
C
P
Open
Table 1. Suggested Components Selection
VOUT (V) R1 (kΩ) R2 (kΩ) RC (kΩ) CC (nF) L (μH)
COUT (μF)
22 x 2
22 x 2
22 x 2
22 x 2
22 x 2
22 x 2
22 x 2
8
27
62
3
11.8
24
24
18
12
8.2
3.6
3
4.7
4.7
4.7
4.7
4.7
4.7
4.7
22
15
5
3.3
2.5
1.5
1.2
1
75
10
25.5
10.5
12
12
6.8
3.6
3.6
3.6
12
24
3
12
2.7
Copyright 2012 Richtek Technology Corporation. All rights reserved.
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is a registered trademark of Richtek Technology Corporation.
www.richtek.com
6
DS7257J-02 September 2012
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
