Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
Advanced
LP2950/LP2951
Monolithic
100mA LOW DROPOUT VOLTAGE REGULATOR
Systems
FEATURES
APPLICATIONS
5V, 3.3V, and 3V Versions at 100mA Output Current
Battery Powered Systems
High Accuracy Output Voltage
Portable Consumer Equipment
Extremely Low Quiescent Current
Cordless Telephones
Low Dropout Voltage
Portable (Notebook) Computers
Extremely Tight Load and Line Regulation
Portable Instrumentation
Very Low Temperature Coefficient
Radio Control Systems
Current and Thermal Limiting
Automotive Electronics
Needs Minimum Capacitance (1
F) for Stability
Avionics
Unregulated DC Positive Transients 60V
Low-Power Voltage Reference
ADDITIONAL FEATURES (LP2951 ONLY)
1.24V to 29V Programmable Output
Error Flag Warning of Voltage Output Dropout
Logic Controlled Electronic Shutdown
GENERAL DESCRIPTION
The LP2950 and LP2951 are micropower voltage regulators ideally suited for use in battery-powered systems. These devices
feature very low quiescent current (typ.75A), and very low dropout voltage (typ.45mV at light loads and 380mV at 100mA)
thus prolonging battery life. The quiescent current increases only slightly in dropout. The LP2950/LP2951 has positive
transient protection up to 60V and can survive unregulated input transient up to 20V below ground.
The LP2950 and LP2951 were designed to include a tight initial tolerance (typ. 0.5%), excellent load and line regulation (typ.
0.05%), and a very low output voltage temperature coefficient, making these devices useful as a low-power voltage reference.
The LP2950 is offered in the 3-pin TO-92 package. LP2951 is available in 8-pin plastic SOIC and DIP packages and offers
three major additional system features. An error flag output warns of a low output voltage, often due to failing batteries on
input. The LP2951 also features the logic-compatible shutdown input which enables the regulator to be switched on and off.
The LP2951 device may be pin-strapped for a 5V, 3.3V, or 3V output, or programmed from 1.24V to 29V with an external
pair of resistors.
ORDERING INFORMATION
PIN CONNECTION
PACKAGE TYPE
OPERATING
TO-92
8 LEAD PDIP
8 LEAD SOIC
TEMP. RANGE
LP2950ACN-X
LP2951ACP-X
LP2951ACS-X
IND.
LP2950CN-X
LP2951CP-X
LP2951CS-X
IND
X = 3.3V, or 3V
8L SOIC/ 8L PDIP
1
2
8
4
3
7
5
6 V
TAP
ERROR
FEEDBACK
OUTPUT
SENSE
SHUTDOWN
INPUT
GROUND
Top View
TO-92
OUTPUT
INPUT
GND
Bottom View
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
LP2950/LP2951
ABSOLUTE MAXIMUM RATINGS
(Note 1)
Input Supply Voltage
-0.3 to +30V
Wave
4 seconds, 260
C
SHUTDOWN Input Voltage,
Infrared
4 seconds, 240
C
Error Comparator Output
Vapor Phase
4 seconds, 219
C
Voltage,(Note 9)
ESD
TBD
FEEDBACK Input Voltage
-1.5 to +30V
(Note 9) (Note 10)
OPERATING RATINGS
(Note 1)
Power Dissipation
Internally Limited
Junction Temperature
+150
C
Max. Input Supply Voltage
30V
Storage Temperature
-65
C to +150
C
Junction Temperature Range
Soldering Dwell Time, Temperature
(T
J
) (Note 8)
LP2950AC-XX, LP2950C-XX
LP2951AC-XX, LP2951C-XX
-40
C to +125
C
ELECTRICAL CHARACTERISTICS
at Vs=Vout+1V, Ta=25C, unless otherwise noted
.
Parameter
Conditions
(Note 2)
LP2950AC
LP2951AC
Min. Typ. Max.
LP2950C
LP2951C
Min. Typ. Max.
Units
3 V Versions (Note 16)
Output Voltage
TJ = 25C (Note 3)
-25C
TJ
85C
Full Operating Temperature Range
2.985
2.970
2.964
3.0
3.0
3.0
3.015
3.030
3.036
2.970
2.955
2.940
3.0
3.0
3.0
3.030
3.045
3.060
V
V
V
Output Voltage
100
A
IL
100 mA
TJ
TJMAX
2.958
3.0
3.042
2.928
3.0
3.072
V
3.3 V Versions (Note 16)
Output Voltage
TJ = 25C (Note 3)
-25C
TJ
85C
Full Operating Temperature Range
3.284
3.267
3.260
3.3
3.3
3.3
3.317
3.333
3.340
3.267
3.251
3.234
3.3
3.3
3.3
3.333
3.350
3.366
V
V
V
Output Voltage
100
A
IL
100 mA
TJ
TJMAX
3.254
3.3
3.346
3.221
3.3
3.379
V
5 V Versions (Note 16)
Output Voltage
TJ = 25C (Note 3)
-25C
TJ
85C
Full Operating Temperature Range
4.975
4.95
4.94
5.0
5.0
5.0
5.025
5.050
5.06
4.95
4.925
4.90
5.0
5.0
5.0
5.05
5.075
5.10
V
V
V
Output Voltage
100
A
IL
100 mA
TJ
TJMAX
4.925
5.0
5.075
4.88
5.0
5.12
V
All Voltage Options
Output Voltage
Temperature Coefficient
(Note 12) (Note 4)
20
50
ppm/C
Line Regulation (Note 14)
6V
Vin
30V (Note 15)
0.03
0.1
0.04
0.2
%
Load Regulation (Note 14)
100
A
IL
100 mA
0.04
0.1
0.1
0.2
%
Dropout Voltage
(Note 5)
IL = 100
A
IL = 100 mA
50
380
80
450
50
380
80
450
mV
mV
Ground Current
IL = 100
A
IL = 100 mA
75
8
120
12
75
8
120
12
A
mA
Current Limit
Vout = 0
160
200
160
200
mA
Thermal Regulation
(Note 13)
0.05
0.2
0.05
0.2
%/W
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
LP2950/LP2951
ELECTRICAL CHARACTERISTICS
(Note 2) (Continued)
PARAMETER
CONDITIONS
(Note 2)
LP2950AC
LP2951AC
Min. Typ. Max.
LP2950C
LP2951C
Min. Typ. Max.
Units
Output Noise,
10Hz to 100KHz
CL = 1
F
CL = 200
F
CL = 13.3
F
(Bypass = 0.01
F pins 7 to
1(LP2951))
430
160
100
430
160
100
V rms
V rms
V rms
8-Pin Versions only
LP2951AC
LP2951C
Reference Voltage
1.22
1.235
1.25
1.21
1.235
1.26
V
Reference Voltage
Over Temperature (Note 7)
1.19
1.27
1.185
1.285
V
Feedback Pin Bias Current
40
60
40
60
nA
Reference Voltage Temperature
Coefficient
( Note 12 )
20
50
ppm/C
Feedback Pin Bias Current
Temperature Coefficient
0.1
0.1
nA/C
Error Comparator
Output Leakage Current
V
OH
= 30V
0.01
1
0.01
1
A
Output Low Voltage
Vin = 4.5V
IOL = 400
A
150
250
150
250
mV
Upper Threshold Voltage
(Note 6)
40
60
40
60
mV
Lower Threshold Voltage
(Note 6)
75
95
75
95
mV
Hysteresis
(Note 6)
15
15
mV
Shutdown Input
Input logic Voltage
Low (Regulator ON)
High (Regulator OFF)
2
1.3
0.7
2
1.3
0.7
V
V
Shutdown Pin Input Current
(Note 3)
Vs = 2.4V
Vs = 30V
30
450
50
600
30
450
50
600
A
A
Regulator Output Current in
Shutdown (Note 3)
(Note 11)
3
10
3
10
A
Note 1: Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which operation of the
device is guaranteed. Operating Ratings do not imply guaranteed performance limits. For guaranteed performance limits and associated test conditions, see the
Electrical Characteristics tables.
Note 2: Unless otherwise specified all limits guaranteed for V
IN
= (
V
ONOM
+1)V, I
L
= 100
A and C
L
= 1
F for 5V versions and 2.2
F for 3V and 3.3V versions.
Limits appearing in boldface type apply over the entire junction temperature range for operation. Limits appearing in normal type apply for T
A
= T
J
= 25
C
Additional conditions for the 8-pin versions are FEEDBACK tied to V
TAP
, OUTPUT tied to SENSE and V
SHUTDOWN
0.8V.
Note 3: Guaranteed and 100% production tested.
Note 4: Guaranteed but not 100% production tested. These limits are not used to calculate outgoing AQL levels.
Note 5: Dropout voltage is defined as the input to output differential at which the output voltage drops 100 mV below its nominal value measured at 1V differential.
At very low values of programmed output voltage, the minimum input supply voltage of 2V ( 2.3V over temperature) must be taken into account.
Note 6: Comparator thresholds are expressed in terms of a voltage differential at the feedback terminal below the nominal reference voltage measured at
V
IN
= (
V
ONOM
+1)V. To express these thresholds in terms of output voltage change, multiply by the error amplifier gain = Vout/Vref = (R1 + R2)/R2. For example,
at a programmed output voltage of 5V, the error output is guaranteed to go low when the output drops by 95 mV x 5V/1.235 = 384 mV. Thresholds remain constant
as a percent of V
out
as V
out
is varied, with the dropout warning occurring at typically 5% below nominal, 7.5% guaranteed.
Note 7: V
ref
V
out
(V
in
- 1V), 2.3
V
in
30V, 100
A
I
L
100 mA, T
J
T
JMAX
.
Note 8: The junction-to-ambient thermal resistance are as follows:180
C/W and 160
C/W for the TO-92 (N) package with 0.40 inch and 0.25 inch leads to the
printed circuit board (PCB) respectively, 105
C/W for the molded plastic DIP (P) and 160
C/W for the molded plastic SO-8 (S). The above thermal resistances for
the N, S and P packages apply when the package is soldered directly to the PCB.
Note 9: May exceed input supply voltage.
Note 10: When used in dual-supply systems where the output terminal sees loads returned to a negative supply, the output voltage should be diode-clamped to
ground.
Note 11: V
shutdown
2V, V
in
30V, V
out
=0, Feedback pin tied to 5V
TAP
.
Note 12: Output or reference voltage temperature coefficients defined as the worst case voltage change divided by the total temperature range.
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
LP2950/LP2951
Note 13: Thermal regulation is defined as the change in output voltage at a time T after a change in power dissipation is applied, excluding load or line regulation
effects. Specifications are for a 50mA load pulse at V
IN
=30V (1.25W pulse) for T =10 ms.
Note 14: Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in output voltage due to heating effects are
covered under the specification for thermal regulation.
Note 15: Line regulation for the LP2951 is tested at 150
C for I
L
= 1 mA. For I
L
= 100
A and T
J
= 125
C, line regulation is guaranteed by design to 0.2%. See
typical performance characteristics for line regulation versus temperature and load current.
Note 16: All LP2950 devices have the nominal output voltage coded as the last two digits of the part number. In the LP2951 products, the 3.0V and 3.3V versions
are designated by the last two digits, but the 5V version is denoted with no code of the part number.
BLOCK DIAGRAM AND TYPICAL APPLICATIONS
LP2950-XX
LP2951-XX
INPUT
OUTPUT
GROUND
ERROR
AMPLIFIER
1.23V
REFERENCE
UNREGULATED DC
V
OUT
I
L
100mA
SEE APPLICATION
HINTS
+
+
+
+
-
INPUT
OUTPUT
GROUND
ERROR
AMPLIFIER
1.23V
REFERENCE
UNREGULATED DC
V
OUT
I
L
100mA
SEE APPLICATION
HINTS
+
+
+
+
-
FEED-
BACK
SHUT-
DOWN
SENSE
V
TAP
ERROR
TO CMOS
OR TTL
+
-
+
330k
4
5
6
2
1
8
7
3
FROM
CMOS
OR TTL
50mV
ERROR DETECTION COMPARATOR
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
LP2950/LP2951
TYPICAL PERFORMANCE CHARACTERISTICS
0
40
100
60
160
0
1
2
3
4
5
6
7
8
INPUT VOLTAGE (V)
Quiescent Current
QUIESCENT CURRENT (
A)
125
250
Input Current
25
50
75
100
150
175
200
225
INPUT VOLTAGE (V)
INPUT CURRENT (
A)
5V OUTPUT
-75
0
25 50 75 100 125
5.06
5.0
150
OUTPUT VOLTAGE (V)
Temperature Drift of 3
Representative Units
TEMPERATURE ( C)
5.04
4.98
4.94
-50 -25
0.1
1
10
100
LOAD CURRENT (mA)
GROUND CURRENT (mA)
0.01
0.1
1
10
Quiescent Current
Dropout Characteristics
INPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
R
L
= 50 k
0
60
120
Input Current
10
20
30
50
70
80
90
100
INPUT VOLTAGE (V)
INPUT CURRENT (mA)
-75
0
25 50 75 100 125
120
90
150
QUIESCENT CURRENT (
A)
Quiescent Current
TEMPERATURE ( C)
100
70
60
-50 -25
I
L
= 100
A
-75
0
25 50 75 100 125
10
150
QUIESCENT CURRENT (mA)
Quiescent Current
TEMPERATURE ( C)
9
8
7
-50 -25
I
L
= 100mA
50
80
110
20
80
140
120
0
2
5
3
8
0
1
2
3
4
5
6
7
8
INPUT VOLTAGE (V)
Quiescent Current
QUIESCENT CURRENT (
A)
1
4
7
6
0
1
2
3
4
5
6
1
2
3
4
5
6
7
8
9 10
0
0
1
2
3
4
5
6
0
1
2
3
4
5
6
7
8
9 10
0
40
110
5.02
4.96
5V OUTPUT
5V OUTPUT
5V OUTPUT
5V OUTPUT
5V OUTPUT
5V OUTPUT
5V OUTPUT
I
L
= 1 mA
I
L
= 100mA
R
L
= 50
R
L
= 50 k
I
L
= 0
V
IN
= 6V
V
IN
= 6V
R
L
= 50
0.2%
R
L
=
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