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ADVANCED INFORMATION
describes products that are in the planning or early design stage. Specifications may change in any manner without
notice. Contact Fairchild Semiconductor for current information.
A
www.fairchildsemi.com
Features
Combines 5V precision linear regulator and boost-mode
DC-DC converter
High efficiency – 85% typical
6V to 22V input range (30V peak)
Independent output enable control
10
m
A shutdown current
Operates with companion RC5023 to form complete
notebook computer power supply
8 pin SOIC package
Applications
Complete notebook PC power supply when combined
with RC5023 triple output DC-DC converter
Sub-notebooks and PDAs
PCMCIA and LCD panels
Description
The RC5011 is a combination 5V precision linear regulator
and switch-mode boost converter suitable for use in note-
book PC power supplies. The 5V regulator can drive loads in
excess of 40mA, while the boost converter can be used to
provide 12V for Flash BIOS or PCMCIA requirements.
Operating over a 6V to 22V (30V peak) input range, the
RC5011 can be used as a standalone IC acheiving switch
mode efficiencies of up to 85%. The RC5011 can also be
used with the Fairchild Semiconductor RC5023 triple output
DC-DC converter to generate the 5V, 3.3V, 12V and 2.xV
required for typical Pentium
notebook computers. When
used with the RC5023, the RC5011 acts as an input stage
that provides 5V for the RC5023 Vcc as well as 12V for
BIOS or PCMCIA. Using this scheme, system efficiencies of
88% can be realized for the entire 4-output solution.
Block Diagram
+5V REGULATOR
RC5011
INTERNAL
REGULATOR
& REFERENCE
OSC
1.25V
GND
EN12V
EN5V
+VBAT
VOUT
DRV
VFB
outin–
CX
RC5011
S tep-up Regulator for Notebook Computers
Rev. 0.5.1