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and limited characterization. They may change without notice. Contact Raytheon for current information.
and limited characterization. They may change without notice. Contact Fairchild Semiconductor for current information.
PRELIMINARY INFORMATION
describes products that are not in full production at the time of printing. Specifications are based on design goals
www.fairchildsemi.com
Features
High accuracy output voltage
Guaranteed 100 mA output current
Extremely low quiescent current
Extremely tight load and line regulation
Requires only a 1.0
m
F output capacitor for stability
Internal Current and Thermal Limiting
Error flag warns of output dropout
Logic-controlled electronic shutdown
Output programmable from 1.24 to 29V
Fixed 3.3V version available
8 lead SOIC package
Description
The RC2951 is a voltage regulator specifically designed to
maintain proper regulation with a very low dropout voltage
(Typ. 40mV at light loads and 380 mV at 100mA). It has a
low quiescent bias current of 75
m
A and is capable of supply-
ing output currents in excess of 100mA. It has internal cur-
rent and thermal limiting protection. The output can be
programmed from 1.24V to 29V with two external resistors.
A fixed output voltage (3.3V) is also available.
The error flag output can be used as power-on reset for
warning of a low output voltage. The Shutdown input feature
allows a logic level signal to turn on and off the regulator
output. The RC2951 is ideally suited for battery powered
computer, consumer, and industrial equipment where an
extension of useful battery life is desirable. The RC2951 is
available in an 8-pin SOIC package.
Block Diagram
Unregulated DC
+
Shut
Down
Feed-
Back
Error
Amplifier
1.23V
Reference
From
CMOS
or TTL
To CMOS
or TTL
Input
Output
Sense
330k
60 mV
3
7
8
1
2
6
5
4
V
TAP
I
L
2
100 mA
V
OUT
See Application
Discussion
Error Detection Comparator
Ground
Error
+
+
+
–
+
–
+
RC2951
Adjustable Mic ropower Voltage Regulator
Rev. 0.9.3