LP2950/LP2951 100mA Low Drop Out Voltage Regulators
FEATURES
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High accuracy output voltage
Guaranteed 100mA output
Very low quiescent current
Low dropout voltage
Extremely tight load and line regulation
Very low temperature coefficient
Needs only 1µF for stability
Error Flag warns of output dropout
Logic-Controlled electronic shutdown
Output programmable from 1.24 to 29V
APPLICATIONS
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Battery powered systems
Cordless telephones
Radio control systems
Portable/Palm top/Notebook computers
Portable consumer equipment
Portable Instrumentation
Avionics
Automotive Electronics
SMPS Post-Regulator
Voltage Reference
PRODUCT DESCRIPTION
The LP2950-XX/LP2951-XX is a low power voltage regulator. This device excellent choice for use in battery powered application such as c
ordless telephone, radio control systems, and portable computers.
The LP2950-XX/LP2951-XX features very low quiescent current (75µA Typ.) and very low drop output voltage (Typ.
40mV at light load and 380mV at 100mA). This includes a tight initial tolerance of 0.5% typ., extremely good load
and line regulation of 0.05% typ., and very low output temperature coefficient, making the LP2950-XX/LP2951-XX
useful as a low-power voltage reference.
The error flag output feature is used as power-on reset for warn of a low output voltage, due to following batteries on input. Other feature i
s the logic-compatible shutdown input which enable the regulator to be switched on and off.
The LP2951-XX is available in 8-pin plastic packages. The regulator output voltage may be pin-strapped for a -XX volt or programmed from
1.24 volt to 29 volts with external pair of resistors.
The LP2950-XX is offered in 3-pin TO-92 package compatible with other fixed regulator.
Absolute Maximum Ratings
Power Dissipation
Lead Temperature
(Soldering, 5 seconds)
Storage Temperature Range
Operating Junction Temperature Range
Input Supply Voltage
Feedback Input Voltage
Shutdown Input Voltage
Error Comparator Output
Internally Limited
260°C
-65°C to+150°C
-55°C to +150°C
-0.3 to +30V
-1.5 to +30V
-0.3 to +30V
-0.3 to +30V
Pin Connection
LP2951-XX
Device Selection Guide
V u
, V
ot
Top View
TO-92 Plastic Package
(LP2950-XX only)
Device
olts
2.85*
LP2950-2.85, LP2951-2.85
3.0
LP2950-3.0, LP2951-3.0
3.3
LP2950-3.3, LP2951-3.3
5.0
LP2950-5.0, LP2951-5.0
* - other versions are also available
Vout = 2.0V to 5.0V. Please consult factory for
more information
Bottom View
Figure 1. Adjustable Regulator
LP2950/LP2951 100mA Low Drop Out Voltage Regulators
E E T I A C A A T RS I Sa T
a
= 5
o
,V
N
1 Vu l s oh r i en t d
L C RC L H R C E I TC ( t
2 C
I
= 5 ; ne s t ew
s oe )
Parameter
Output Voltage
Output Voltage
Output Voltage Temperature Coefficient
Line Regulation (Note 3)
Load Regulation (Note 3)
Dropout Voltage (Note 5)
Ground Current
Dropout Ground Current
Current Limit
Thermal Regulation
Output Noise, 10Hz to 100KHz
Conditions
(
Note 2
)
-25°C≤T
J
≤85°C
Full Operating Temperature
100µA
≤
I
L
≤
100mA, T
J
≤T
JMAX
(Note 1)
V
0
+ 1V
≤
V
in
≤
30V (Note 4)
100µA
≤
I
L
≤
100mA
I
L
=100
µA
I
L
=100 mA
I
L
=100
µA
I
L
=100 mA
V
in
=V
0
- 0.5V, I
L
=100
µA
Vout=0
C
L
=1µF
C
L
=200µF
C
L
=3.3µF
(Bypass=0.01
µF
pins 7 to 1
(LP2951-XX))
Min
0.985 |V
0
|
0.98 |V
0
|
0.976|V
0
|
Typ
V
0
V
0
50
0.04
0.1
50
380
75
8
110
160
0.05
430
160
100
Max
1.015 |V
0
|
1.02 |V
0
|
1.024 |V
0
|
150
0.4
0.3
80
450
120
12
170
200
0.2
Units
V
ppm/°C
%
%
mV
µA
mA
µA
mA
%/W
µV
rms
8-pin Versions only
Reference Voltage
Reference Voltage
Feedback Pin Bias Current
Reference Voltage Temperature Coefficient
Feedback Pin Bias Current Temperature Coefficient
Error Comparator
Output Leakage Current
Output Low Voltage
Upper Threshold Voltage
Lower Threshold Voltage
Hysteresis
Shutdown Input
Input Logic Voltage
Shut down Pin Input Current
Regulator Output Current in Shutdown
Voh=30V
Vin=4.5V, I
OL
=400
µA
(Note 8)
(Note 8)
(Note 8)
Low (Regulator ON)
High (Regulator OFF)
V
S
=2.4V
V
S
=30V
(Note 9)
V
OUT
= 5.0 V
3.3V
≤
V
OUT
< 5.0 V
40
0.01
150
60
75
15
1.3
2
30
450
3
50
600
10
20
µA
1.0
250
95
µA
mV
(Note 7)
Over Temperature (Note 6)
1.21
1.185
20
50
0.1
1.235
1.26
1.285
40
n
A
pm
p/
°C
n/
A
°C
V
0.7
V
30
2.0V
≤
V
OUT
< 3.3 V
Note 1: Output or reference voltage temperature coefficients defined as the worst case voltage change divided by the total temperature range.
Note 2: Unless otherwise specified all limits guaranteed for T
J
= 25°C, Vin = V
0
+ 1V, I
L
= 100µA and C
L
= 1µF. Additional conditions for the
8-pin versions are feedback tied to -XX V tap and output tied to output Sense (V
out
= XX V) and V
shutdown
≤
0.8 V
Note 3: Regulations 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 4: Line regulation for LP2951-XX is tested at 150°C for I
L
= 1mA. For I
L
= 100µA 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 5: Dropout voltage is defined as the input to output differential at which the output voltage drops 100mV 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: Vref
≤
Vout
≤
(Vin - 1V), 2.3V
≤
Vin
≤
30V, 100µA
≤
I
L
≤
100mA, T
J
≤
T
JMAX
Note 7: Output or reference voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range
Note 8: Comparator thresholds are expressed in terms of a voltage differential at the feedback terminal below the nominal reference voltage
measured at V
0
+ 1V input. To express these thresholds in terms of output voltage change, multiply by the error amplifier gain = V
out
/V
ref
= (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 95mV x 5V/
1.235V=384mV. Thresholds remain constant as a percent of Vout as Vout is varied , with the dropout warning occurring at typically 5% below
nominal, 7.5% guaranteed.
Note 9: V
shutdown
≥
2V, Vin
≤
30V, Vout = 0, Feed-back pin tied to -XX V Tap.
LP2950/LP2951 100mA Low Drop Out Voltage Regulators
Block Diagram and Typical Applications
LP2950-XX
LP2951-XX
PAD LOCATION LP2951-XX
(For LP2950-XX fixed versions see Note 1)
Chip Size: 2.05 x 1.15 mm
Pad N
1
2
3
4
5
6
7
8
Pad Name
Output
Sense
Shutdown
Ground
Error
XX V tap
Feedback
Input
X (µm)
440
810
1250
1865
1865
935
735
440
Y (µm)
110
110
110
110
950
950
950
950
Note 1: For LP2950-XX: 8 - connected to Input
1,2 - connected to Output
4 - connected to GND