LP2950/LP2951
Series of Adjustable Micropower Voltage Regulators
General Description
The LP2950 and LP2951 are micropower voltage regulators
with very low quiescent current (75�A typ.) and very low
dropout voltage (typ. 40mV at light loads and 380mV at
100mA). They are ideally suited for use in battery-powered
systems. Furthermore, the quiescent current of the LP2950/
LP2951 increases only slightly in dropout, prolonging battery
life.
The LP2950-5.0 is available in the surface-mount D-Pak
package, and in the popular 3-pin TO-92 package for pin-
compatibility with older 5V regulators. The 8-lead LP2951 is
available in plastic, ceramic dual-in-line, or metal can pack-
ages and offers additional system functions.
One such feature is an error flag output which warns of a low
output voltage, often due to falling batteries on the input. It
may be used for a power-on reset. A second feature is the
logic-compatible shutdown input which enables the regulator
to be switched on and off. Also, the part may be pin-strapped
for a 5V, 3V, or 3.3V output (depending on the version), or
programmed from 1.24V to 29V with an external pair of
resistors.
Careful design of the LP2950/LP2951 has minimized all
contributions to the error budget. This includes a tight initial
tolerance (.5% typ.), extremely good load and line regulation
(.05% typ.) and a very low output voltage temperature coef-
ficient, making the part useful as a low-power voltage refer-
ence.
Features
n
5V, 3V, and 3.3V versions available
n
High accuracy output voltage
n
Guaranteed 100mA output current
n
Extremely low quiescent current
n
Low dropout voltage
n
Extremely tight load and line regulation
n
Very low temperature coefficient
n
Use as Regulator or Reference
n
Needs minimum capacitance for stability
n
Current and Thermal Limiting
n
Stable with low-ESR output capacitors
LP2951 versions only
n
Error flag warns of output dropout
n
Logic-controlled electronic shutdown
n
Output programmable from 1.24 to 29V
Block Diagram and Typical Applications
LP2950
LP2951
00854625
00854601
May 2003
LP2950/LP2951
Series
of
Adjustable
Micropower
V
oltage
Regulators
� 2003 National Semiconductor Corporation
DS008546
www.national.com
Connection Diagrams
TO-92 Plastic Package (Z)
00854602
Bottom View
Dual-In-Line Packages (N, J)
Surface-Mount Package (M, MM)
00854626
Top View
Metal Can Package (H)
00854619
Top View
10-Lead Ceramic Surface-Mount Package (WG)
00854664
Top View
TO-252 (D-Pak)
00854670
Front View
8-Lead LLP
00854671
Pin 4 is fused to center DAP
Top View
LP2950/LP2951
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Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
Input Supply Voltage
-0.3 to +30V
SHUTDOWN Input Voltage,
Error Comparator Output
Voltage, (Note 9)
FEEDBACK Input Voltage
-1.5 to +30V
(Note 9) (Note 10)
Power Dissipation
Internally Limited
Junction Temperature (T
J
)
+150�C
Ambient Storage Temperature
-65� to +150�C
Soldering Dwell Time, Temperature
Wave
Infrared
Vapor Phase
4 seconds, 260�C
10 seconds, 240�C
75 seconds, 219�C
ESD Rating
Human Body Model(Note 18)
2500V
Operating Ratings
(Note 1)
Maximum Input Supply Voltage
30V
Junction Temperature Range
(T
J
) (Note 8)
LP2951
-55� to +150�C
LP2950AC-XX, LP2950C-XX,
LP2951AC-XX, LP2951C-XX
-40� to +125�C
Electrical Characteristics
(Note 2)
Parameter
Conditions
(Note 2)
LP2951
LP2950AC-XX
LP2950C-XX
Units
LP2951AC-XX
LP2951C-XX
Tested
Tested
Design
Tested
Design
Typ
Limit
Typ
Limit
Limit
Typ
Limit
Limit
(Notes 3, 16)
(Note 3) (Note 4)
(Note 3) (Note 4)
3V Versions (Note 17)
Output Voltage
T
J
= 25�C
3.0
3.015
3.0
3.015
3.0
3.030
V max
2.985
2.985
2.970
V min
-25�C
T
J
85�C
3.0
3.0
3.030
3.0
3.045
V max
2.970
2.955
V min
Full Operating
3.0
3.036
3.0
3.036
3.0
3.060
V max
Temperature Range
2.964
2.964
2.940
V min
Output Voltage
100�A
I
L
100mA
3.0
3.045
3.0
3.042
3.0
3.072
V max
T
J
T
JMAX
2.955
2.958
2.928
V min
3.3V Versions (Note 17)
Output Voltage
T
J
= 25�C
3.3
3.317
3.3
3.317
3.3
3.333
V max
3.284
3.284
3.267
V min
-25�C
T
J
85�C
3.3
3.3
3.333
3.3
3.350
V max
3.267
3.251
V min
Full Operating
3.3
3.340
3.3
3.340
3.3
3.366
V max
Temperature Range
3.260
3.260
3.234
V min
Output Voltage
100�A
I
L
100mA
3.3
3.350
3.3
3.346
3.3
3.379
V max
T
J
T
JMAX
3.251
3.254
3.221
V min
5V Versions (Note 17)
Output Voltage
T
J
= 25�C
5.0
5.025
5.0
5.025
5.0
5.05
V max
4.975
4.975
4.95
V min
-25�C
T
J
85�C
5.0
5.0
5.05
5.0
5.075
V max
4.95
4.925
V min
Full Operating
5.0
5.06
5.0
5.06
5.0
5.1
V max
Temperature Range
4.94
4.94
4.9
V min
Output Voltage
100�A
I
L
100mA
5.0
5.075
5.0
5.075
5.0
5.12
V max
T
J
T
JMAX
4.925
4.925
4.88
V min
LP2950/LP2951
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