Solved by
LP2950/LP2951
TM
100mA Low Dropout Voltage Regulators
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Lead Free, RoHS Compliant Packages:
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Now Available in Lead Free Packaging
UNREGULATED DC
+
7
FEEDBACK
8
INPUT
OUTPUT
5V @ 00mA
MAX
2
SENSE
FROM
CMOS OR
TTL
SHUTDOWN
0 mV
+
_
80kΩ
ERROR
AMPLIFIER
5V TAP
0kΩ
+
5
0kΩ
+
+
.2V
+
_
ERROR DETECTION
COMPARATOR
______
ERROR
µF
.
TO CMOS OR
TTL
.
REFERENCE
GROUND
Mar8-07 Rev E
LP2950-5 Low Dropout Linear Regulator
© 2007 Sipex Corporation
½
½
½
½
½
≤
≤
µ ≤
≤
≤
½
≤
≤
µ ≤
≤
≤
≤
≤
µ ≤
≤
½
µ
½
½
µ
½
½
½ µ
½
µ
½
µ
½
µ
µ
µ
µ
Mar8-07 Rev E
LP2950-5 Low Dropout Linear Regulator
© 2007 Sipex Corporation
2
LP2950/51
PARAMETER
CONDITIONS
(Note 2)
8-Pin Versions only (Continued)
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
Thermal
Resistance
θ
JA
Low (Regulator ON)
High (Regulator OFF)
V
S
= 2.4V
V
S
= 30V
(Note 8)
8 Pin SOIC
3 Pin TO-92
2.0
1.3
30
675
3
128. 4
131.9
LP2951AC
Min. Typ.
Max.
20
0.1
Min.
LP2951C
Typ. Max.
UNITS
50
0.1
ppm/°C
nA/°C
V
OH
= 30V
V
IN
= 4.5V
I
OL
= 400
μA
(Note 7)
(Note 7)
(Note 7)
40
0.01
150
60
75
15
1
250
40
95
0.01
150
60
75
15
1
250
μA
mV
mV
95
mV
mV
0.7
50
800
10
2.0
1.3
30
675
3
0.7
50
800
10
V
V
μA
μA
μA
°C/W
°C/W
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, V
IN
= 6V, I
L
= 100
μA
and C
L
= 1μF. Additional conditions for the 8-pin versions are feedback
tied to 5V tap and output tied to output sense (V
OUT
= 5V) and V
SHUTDOWN
≤0.8V.
Note 3:
Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes i n output voltage due to heating effects are
covered under the specification for thermal regulation.
Note 4:
Line regulation for the LP2951 is tested at I
L
= 1mA. For I
L
= 100
μA
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 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:
V
REF
≤V
OUT
≤(V
IN
- 1V), 2.3
≤V
IN
≤30V,
100μA≤I
L
≤100mA,
T
J
≤T
JMAX
.
Note 7:
Comparator thresholds are expressed in terms of a voltage differential at the feedback terminal below the nomi nal reference voltage measured at 6V input. To
express these thresholds in terms of output voltage change, multiply by the error amplifier gain = V
OUT
/V
REF
= (R
1
+ R
2
)/R
2
. 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 8:
V
SHUTDOWN
≥2V,
V
IN
≤30V,
V
OUT
=0, Feedback pin tied to 5V Tap.
Note 9:
All typical values are not guaranteed. The value could vary from lot to lot.
Mar8-07 Rev E
LP2950-5 Low Dropout Linear Regulator
© 2007 Sipex Corporation
6
5
OUTPUT VOLTAGE (VOLTS)
INPUT CURRENT (µA)
250
225
175
150
125
100
75
50
25
0
0
1
2
3
4
5
6
0
1
2
3
4
5
6 7
8
9 10
INPUT VOLTAGE (VOLTS)
INPUT VOLTAGE (VOLTS)
R
L
=
8
GROUND PIN CURRENT (mA)
10
200
4
R
L
=
R
L
= 50k
Ω
1
3
R
L
=50kΩ
2
1
0
8
0.1
0.01
0.1
1
10
100
LOAD CURRENT (mA)
Dropout Characteristics
Input Current
Quiescent Current
16
320
280
GROUND CURRENT (µA)
INPUT CURRENT (mA)
GROUND CURRENT (mA)
240
200
160
120
80
40
0
0
1
2
3
4
5
6
7
8
I
L
= 1mA
I
L
= 0
160
150
140
130
120
110
100
90
80
70
60
50
40
30
20
10
0
0
1
2
3
4
5
6
R
L
=50
Ω
V
OUT
= 5V
12
V
IN
= 6V
I
L
= 100mA
8
4
7
8
9 10
-75 -50 -25
0
25 50 75 100 125 150
INPUT VOLTAGE (VOLTS)
TEMPERATURE (ºC)
INPUT VOLTAGE (VOLTS)
Ground Current
16
14
Input Current
190
Ground Current
QUIESCENT CURRENT (µA)
GROUND CURRENT (mA)
12
I
L
=100mA
170
V
IN
=6V
I
L
=100uA
10
8
6
4
2
0
0
1
2
3
4
5
6
7
8
INPUT VOLTAGE
150
130
-75 -50 -25
0
25 50 75 100 125 150
TEMPERATURE (ºC)
Ground Current
Quiescent Current
Mar8-07 Rev E
LP2950-5 Low Dropout Linear Regulator
© 2007 Sipex Corporation
600
I
L
= 100mA
SHORT CIRCUIT CURRENT (mA)
500
400
DROP-OUT VOLTAGE (mV)
170
160
150
140
130
120
110
110
-75 -50 -25
500
DROP-OUT VOLTAGE (mV)
400
300
100
50
0
-75 -50 -25
0
25 50 75 100 125 150
TEMPERATURE (ºC)
300
~
~
200
T
J
= 25ºC
I
L
= 100
µA
100
0
100µA
1mA
10mA
100mA
0
25 50 75 100 125 150
OUTPUT CURRENT
TEMPERATURE (ºC)
Drop-Out Voltage
8
V
OUT
= 5V
Drop-Out Voltage
2.5
2.0
SINK CURRENT (mA)
Short Circuit Current
100
mV
T
A
= 125ºC
INPUT OUTPUT VOLTAGE
VOLTAGE CHANGE
6
COMPARATOR OUTPUT (V)
50
mV
0
-50
mV
~
~
8V
6V
4V
0
200
400
TIME(µs)
C
L
= 1
µF
I
L
= 1mA
V
OUT
= 5V
4
HYSTERESIS
1.5
1.0
0.5
T
A
= 25ºC
2
0
-2
0
1
PULLUP RESISTOR TO
SEPARATE 5V SUPPLY
T
A
= -55ºC
2
3
4
5
0.0
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9
OUTPUT LOW VOLTAGE (V)
INPUT VOLTAGE (V)
600
800
Error Comparator Output
10
OUTPUT IMPEDANCE (OHMS)
LP2951 Comparator Sink Current
90
80
RIPPLE REJECTION (dB)
Line Transient Response
90
80
C
L
= 1µF
V
IN
= 6V
V
OUT
= 5V
5
2
1
0.5
0.2
0.1
0.05
0.02
0.01
10
I
O
= 100
µA
I
O
= 1mA
I
O
= 100mA
I
L
= 0
60
50
40
30
20
C
L
= 1
µF
V
IN
= 6V
V
OUT
= 5V
I
L
= 100
µA
RIPPLE REJECTION (dB)
70
70
60
50
40
30
20
I
L
= 1mA
V
OUT
= 5V
C
L
= 1
µF
I
L
= 10mA
100
1K
10K
100K
1M
10
1
10
2
10
3
10
4
10
5
10
6
10
1
10
2
10
3
10
4
10
5
10
6
FREQUENCY (Hz)
FREQUENCY (Hz)
FREQUENCY (Hz)
Output Impedance
Ripple Rejection
Ripple Rejection
Mar8-07 Rev E
LP2950-5 Low Dropout Linear Regulator
© 2007 Sipex Corporation
5
