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T
www.fairchildsemi.com
Features
Synchronous rectification
High precision
High efficiency
Input and output voltage feedback
6V to 20V input voltage range
±
10% current limit precision
TSSOP24
5V, 5V-Always, 12V and 3.3V outputs
UVLO
OVP
Applications
Notebook and PDA PC’s
Hand-held portable instruments
Description
The RC5230 is a high efficiency and high precision
DC/DC controller for notebooks. Double voltage mode-
input and output voltage feedback- allows for fast loop
response over a wide range of input and output variations.
This scheme also allows for minimum power dissipation as a
small value for the sense resistor is selected to set current
(as opposed to having to sense current over the entire
current range as required in other schemes). The tightly
controller current limit threshold allows for a tight design of
magnetics and discrete transistors for minimum cost and
space at maximum performance.
Block Diagram
COMP3.3
6-20V
SS/ONOFF3.3
SS/ONOFF5
PGOOD
S
D
W
N
P
G
N
D
S
G
N
D
2HSD3.3
3 LSD3.3
6
7
12
13
14 15
RC5230
TSSOP24
24
HSD5
23
LSD5
22
21
17
16
1
Vin
4 FB3.3+
5 V
VSB3.3
FB3.3–
8
9
10
11
5VALWAYS
FPWM
VFB12
IFB5-
VSB5
COMP5
IFB5+
SW12
18
19
20
SS
ON
OFF
12
3.3V
5V
12V
S/DWN12
RC5230
S ystem Elec tronic s Regulator for Mobile PC’s