LND2931
100mA Low Dropout Voltage Regulator
DATA SHEET
GENERAL DESCRIPTION
3- terminal regulators ( To-220-5, SO-8
for LND2931)
100mA output within 2% over
temperature
Very low quiescent current
Low dropout voltage (300mV Typ)
Extremely tight load and line regulation
Very low temperature coefficient
Current and thermal limiting
Unregulated DC input can withstand
20V reverse battery and +60V positive
transients
Direct replacement for National
LM2931 fixed series, but has lower
ground current, higher accuracy of
output voltage and extremely tight load
and line regulation. For adjust model
LND2931 see typical applications on
figure 2.
FEATURES
This series of fixed-voltage and adjustable
monolithic micropower voltage regulators is
designed for a wide range of applications. This
device is an excellent choice for use in battery-
powered application. Furthermore, the
quiescent current increases only slightly at
dropout, which prolongs battery life. This series
of fixed-voltage ( Typ. 60mV at light load and
300mV at 100mV) 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. This series of fixed-
voltage and adjustable regulators is offered in 3-
pin TO-92 package (TO-220-5, SO-8 for
LND2931) compatible with other fixed-voltage
regulators.
APPLICATIONS
High-efficiency linear regulators
Battery
powered
systems
Portable/Palm top/ Notebook
Computers
Portable consumer equipment
Portable
instrumentation
Automotive
Electronics
SMPS
Post
Regulator
Linear Dimensions, Inc. 445 East Ohio Street, Chicago IL 60611 USA tel 312.321.1810 fax 312.321.1830
www.lineardimensions.com
PIN CONFIGURATION
1
2
3
4
5
6
7
8
Output
Shutdown
GND
Feedback
Input
LND2931
GND
GND
GND
Power Dissipation
Internally Limited
Lead Temperature(Soldering, 5 seconds)
260C
Storage Temperature Range
-65C to +150C
Operating Junction Temperature Range
-55C to +150C
Input Supply Voltage
-20V to +35V
Vout , VOLTS
Device
3.3V*
LND2931-3.3
5.0V
LND2931-5.0
8.0V
LND2931-8.0
8.5V
LND2931-8.5
9.0V
LND2931-9.0
10.0V
LND2931-10
12.0V
LND2931-12
15.0V
LND2931-15
3.0v to 24V
LND2931
* Other fixed versions are also available, V
OUT
=2.0V to 5.0V. Please consult for more information.
ABSOLUTE MAXIMUM RATINGS
LND2931
DEVICE SELECTION GUIDE
Linear Dimensions, Inc. 445 East Ohio Street, Chicago IL 60611 USA tel 312.321.1810 fax 312.321.1830
www.lineardimensions.com
OUTPUT
GND
INPUT
TO-92
(Bottom View)
TO-220
INPUT
OUTPUT
GND
(Top View)
(T
J
=25C, I
O
=100A, V
IN
=14V (for 2931-15, V
IN
=16V), C
O
=100F; unless otherwise noted)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Output Voltage
(Fixed Model)
-25 C
T
J
85C
Full Operating Temperature
0.985 |V
O
|
0.98 |V
O
|
V
O
1.015|V
O
|
1.02 |V
O
|
Output Voltage
(Fixed Model)
100A
I
L
100mA, T
J
Tjmax
0.975 |V
O
|
V
O
1.025 |V
O
|
Input Supply Voltage
26
V
Output Voltage
Temperature Coefficient
(Note 1)
50
150
ppm/C
Line Regulation (Note 2)
13V
Vin 26V (Note 3)
0.1
0.4
%
Load Regulation(Note 2)
1mA
I
L
100mA
0.1
0.3
%
Dropout Voltage(Note 4)
I
L
=10mA
I
L
=100mA
60
300
200
600
mV
Ground Current (Note 5)
I
L
=100A
I
L
=10mA
I
L
=100mA
100
0.9
8
150
1.5
12
A
mA
mA
Dropout Ground Current
(Note 5)
V
in
=V
out
-0.5V , I
L
=100A
110
170
A
Current Limit
V
out
=0
160
200
mA
Thermal Regulation(Note6)
0.05
0.2
% / W
Output Noise, 10Hz to
100KHz I
L
= 100mA
C
L
=2.2F
C
L
=3.3F
C
L
=33F
500
350
120
V RMS
Ripple Rejection Ratio
I
O
=10mA,f=120Hz,C
o
=100F,
Vin=V
o
+3V+2Vpp
60
dB
TO-220-5, SO-8 Versions Only
Reference Voltage
1.21
1.235
1.26
Reference Voltage
Over Temperature (note 7)
1.185
1.285
V
Feedback Pin Bias Current
20
40
nA
Reference Voltage
Temperature Coefficient
(Note 1)
50
ppm/C
Feedback Pin Bias Current
Temperature Coefficient
0.1
nA/C
Shutdown Input
Input Logic Voltage
Low(Regulator ON)
High (Regulator OFF)
2
1.3
0.7
V
Shutdown Pin Input
Current
V
S
= 2.4V
V
S
= 26V
30
450
50
600
(Note 8)
5.0V
V
out
<15.0V
10
3.3V
V
out
<5.0 V
20
Regulator Output Current
in Shutdown
2.0V
V
out
<3.3V
30
A
ELECTRICAL CHARACTERISTICS
LND2931
Linear Dimensions, Inc. 445 East Ohio Street, Chicago IL 60611 USA tel 312.321.1810 fax 312.321.1830
www.lineardimensions.com
Note 1: Output or reference voltage temperature coefficients defined as the worst case voltage change
divided by the total temperature range.
Note 2: Regulations are 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 3: Line regulation is tested at 150C for I
L
= 1mA, for I
L
=100A and T
J =
125C, line regulation is
guaranteed by design to 0.2%. For LND2931-15 16V<= Vin <=26V.
Note 4: Dropout voltage is defined as the input to output differential at which the output voltage drops 2%
below its nominal value measured at 1V differential.
Note 5: Ground pin current is the regulator quiescent current. The total current drawn from the source is
the sum of the ground pin current and output load current.
Note 6: Thermal regulation is the change in output voltage at a time T after a change in power dissipation,
excluding load or line regulation effects. Specifications are for a 50mA load pulse (1.25W pulse) for
T=10ms.
Note7: Vref
V
out
(Vin-1V), 2.3V
Vin
26V, 100A
I
L
100mA, T
J
T
jmax.
Note 8: Vshutdown
2V, V
IN
26V, Vout =0V.
LND2931
BLOCK DIAGRAM AND TYPICAL APPLICATIONS
Linear Dimensions, Inc. 445 East Ohio Street, Chicago IL 60611 USA tel 312.321.1810 fax 312.321.1830
www.lineardimensions.com
5V
L
OUTPUT
+
1.23 V
Reference
-
INPUT
GROUND
Unregulated DC
I <= 100mA
+
See
Application
Hints
ERROR
AMPLIFIER
+
60k
182k
Figure 1: Fixed Regulator
+
Vout 1.2A->24A
1
Unregulated DC
From
CMOS
or
TTL
3.3 F
SHUTDOWN
ERROR
AMPLIFIER
7
L
60k
8
2,3,6,7
FEEDBACK
+
+
-
INPUT
5
GROUND
OUTPUT
1.23 V
Reference
+
I <= 100mA
0.01 F
Figure 2:Adjustable Regulator
R2
+
R1
LND2931
TYPICAL APPLICATIONS
Wide Input Voltage Range Current Limiter
5V Current Limiter
Latch Off When Error Flag Occurs
Low Drift Current Source
ERROR
7
V
LND2931
+V
3
ERROR
IN
SHUTDOWN
OUT
+V
*Minimum input-output voltage ranges from
40mV to 400mV, depending on load current.
Current limit is typically 160mA.
4
V
5
1
8
FB
OUT
GND
IN
*V
INPUT
IN
OUTPUT
*V
*Minimum input-output voltage ranges from
40mV to 400mV, depending on load current.
Current limit is typically 160mA.
GND
IN
LND2931
V
5V BUS
1 F
OUT
+V
5V
OUT
+
5
8
FB
R1
SD
+V
GND
1 F
OUT
IN
470k
IN
1
V
OUT
R2
ERROR
V
3
LND2931
470k
RESET
+V
4
7
+
R
+V=
SHUTDOWN
I
I
*V
LOAD
4
1%
LND2931
7
L
3
= 1.23/R
OUT
1.2 30V
1 F
SD
1
L
V
IN
OUT
INPUT
V
8
1 F
FB
GND
+
Linear Dimensions, Inc. 445 East Ohio Street, Chicago IL 60611 USA tel 312.321.1810 fax 312.321.1830
www.lineardimensions.com
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