LP2950 Datasheet, PDF (1/14 Pages) National Semiconductor (TI) – Series of Adjustable Micropower Voltage Regulators

LP2950/2951
Micrel
LP2950/2951
100mA Low-Dropout Voltage Regulator
General Description
Features
The LP2950 and LP2951 are micropower voltage regulators • High accuracy 5V, guaranteed 100 mA output
with very low dropout voltage (typically 40mV at light loads • Extremely low quiescent current
and 380mV at 100mA), and very low quiescent current (75µA • Low-dropout voltage
typical). The quiescent current of the LP2950/LP2951 • Extremely tight load and line regulation
increases only slightly in dropout, thus prolonging battery life. • Very low temperature coefficient
This feature, among others, makes the LP2950 and LP2951 • Use as regulator or reference
ideally suited for use in battery-powered systems.
• Needs only 1µF for stability
• Current and thermal limiting
Available in a 3-Pin TO-92 package, the LP2950 is pin-
compatible with the older 5V regulators. Additional system
functions, such as programmable output voltage and logic- _{LP2951 Versions Only}
controlled shutdown, are available in the 8-pin DIP and 8-pin
SOIC versions of the LP2951.
• Error flag warns of output dropout
Applications
• Logic-controlled electronic shutdown
• Output programmable from 1.24 to 29V
3
• Automotive Electronics
• Voltage Reference
• Avionics
Block Diagram and Pin Configurations
UNREGULATED DC
+
7
8
FEEDBACK
INPUT
1
OUTPUT
FROM
CMOS
OR TTL
3
SHUT-
DOWN
60 mV
+
1.23 V ⁺
REF.
+
182
– _ERROR
kΩ
AMPLIFIER
60
+
kΩ
–
ERROR
DETECTION
COMPARATOR
5V
150 mA
MAX.
2
SENSE
6
5V TAP
5
ERROR
4
GROUND
+
1.5 µF
330
kΩ
TO CMOS
OR TTL
LP2950 and LP2951 Block Diagram
(Pin Numbers Refer to LP2951)
32 1
OUTPUT
INPUT
GROUND
1
OUTPUT
SENSE
2
SHUTDOWN
3
4
GROUND
8
INPUT
7
FEEDBACK
6
5V TAP
5
ERROR
TO-92 Plastic Package Bottom View
(BZ)
DIP and SO Packages
(BN and BM)
See MIC2950 for a part with 1) higher output (150 mA), 2) transient protection (60V), and 3) reverse input protection to –20V)
February 1999
3-35