RT7251A/B
Typical Application Circuit
RT7251A
V
IN
4V to 17V
2 VIN
C
IN
10µF
6 PGOOD
4 EN
GND
SW 1
FB 5
R2
36k
BOOT 3
C
BOOT
10nF
L
15µH
V
OUT
3.3V
1.5A
C
OUT
22µF x 2
PGOOD
Chip Enable
R1
110k
7, 8, 9 (Exposed Pad)
RT7251B
V
IN
4V to 17V
2 VIN
C
IN
10µF
6 PGOOD
4 EN
GND
SW 1
FB 5
R2
15k
BOOT 3
C
BOOT
10nF
L
6.8µH
R1
47k
V
OUT
3.3V
1.5A
C
OUT
22µF x 2
PGOOD
Chip Enable
7, 8, 9 (Exposed Pad)
Table 1. Recommended Component Selection
RT7251A
V
OUT
(V)
1.2
2.5
3.3
5
L (μH)
4.7
10
15
22
R1 (kΩ)
110
110
110
120
R2 (kΩ)
220
51
36
22
C
OUT
(μF)
22 x 2
22 x 2
22 x 2
22 x 2
RT7251B
V
OUT
(V)
1.2
2.5
3.3
5
L (μH)
3.6
4.7
6.8
10
R1 (kΩ)
47
47
47
62
R2 (kΩ)
91
22
15
12
C
OUT
(μF)
22 x 2
22 x 2
22 x 2
22 x 2
Copyright
©
2012 Richtek Technology Corporation. All rights reserved.
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
2
DS7251A/B-01 April 2012