LM340
Three-Terminal Positive
Fixed Voltage Regulators
This family of fixed voltage regulators are monolithic integrated
circuits capable of driving loads in excess of 1.0 A. These
threeterminal regulators employ internal current limiting, thermal
shutdown, and safearea compensation. Devices are available with
improved specifications, including a 2% output voltage tolerance, on
Asuffix 5.0, 12 and 15 V device types.
Although designed primarily as a fixed voltage regulator, these
devices can be used with external components to obtain adjustable
voltages and currents. This series of devices can be used with a
seriespass transistor to boost output current capability at the
nominal output voltage.
Output Current in Excess of 1.0 A
No External Components Required
Output Voltage Offered in 2% and 4% Tolerance*
Internal Thermal Overload Protection
Internal Short Circuit Current Limiting
Output Transistor SafeArea Compensation
ORDERING INFORMATION
Device
Output Voltage
and Tolerance
Operating
Temperature Range
Package
LM340T5.0
5.0 V
4%
LM340AT5.
0
5.0 V
2%
LM340T6.0
6.0 V
4%
LM340T8.0
8.0 V
4%
LM340T12
12 V
4%
T
J
= 0
to +125
C
Plastic Power
LM340AT12
12 V
2%
T
J
= 0 to +125 C
Plastic Power
LM340T15
15 V
4%
LM340AT15
15 V
2%
LM340T18
18 V
4%
LM340T24
24 V
4%
* 2% regulators are available in 5, 12 and 15 V devices.
ON Semiconductort
LM340, A
Series
SEMICONDUCTOR
TECHNICAL DATA
THREETERMINAL
POSITIVE FIXED
VOLTAGE REGULATORS
Pin 1. Input
2. Ground
3. Output
T SUFFIX
PLASTIC PACKAGE
CASE 221A
Heatsink surface is connected to Pin 2.
3
1
2
Simplified Application
A common ground is required between the input and
the output voltages. The input voltage must remain
typically 1.7 V above the output voltage even during
the low point on the input ripple voltage.
XX these two digits of the type number indicate
voltage.
* C
in
is required if regulator is located an
appreciable distance from power supply filter.
** C
O
is not needed for stability; however, it does
improve transient response. If needed, use a
0.1
F ceramic disc.
LM340-XX
Input
C
in
*
0.33
F
C
O
**
Output
Semiconductor Components Industries, LLC, 2001
March, 2001 Rev. 2
1
Publication Order Number:
LM340/D
LM340, A Series
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2
MAXIMUM RATINGS
(T
A
= +25
C unless otherwise noted.)
Rating
Symbol
Value
Unit
Input Voltage (5.0 V 18 V)
Input Voltage
(24 V)
V
in
35
40
Vdc
Power Dissipation and Thermal Characteristics
Plastic Package
T
A
= +25
C
Derate above T
A
= +25
C
Thermal Resistance, JunctiontoAir
T
C
= +25
C
Derate above T
C
= +75
C (See Figure 1)
Thermal Resistance, JunctiontoCase
P
D
1/
JA
JA
P
D
1/
JA
JC
Internally Limited
15.4
65
Internally Limited
200
5.0
W
mW/
C
C/W
W
mW/
C
C/W
Storage Temperature Range
T
stg
65 to +150
C
Operating Junction Temperature Range
T
J
0 to +150
C
Representative Schematic Diagram
1.0k
210
Input
16k
6.7V
300
1.0k
100
200
3.6k
6.4k
520
3.0k
5.6k
10pF
300
13
0.12
Output
200
50
2.6k
6.0k
40
pF
Gnd
2.8k
3.9k
2.0k
6.0k
1.0k
LM340, A Series
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3
LM3405.0
ELECTRICAL CHARACTERISTICS
(V
in
= 10 V, I
O
= 500 mA, T
J
= T
low
to T
high
[Note 1], unless otherwise noted.)
Characteristics
Symbol
Min
Typ
Max
Unit
Output Voltage (T
J
= +25
C)
I
O
= 5.0 mA to 1.0 A
V
O
4.8
5.0
5.2
Vdc
Line Regulation (Note 2)
8.0 Vdc to 20 Vdc
7.0 Vdc to 25 Vdc (T
J
= +25
C)
8.0 Vdc to 12 Vdc, I
O
= 1.0 A
7.3 Vdc to 20 Vdc, I
O
= 1.0 A (T
J
= +25
C)
Reg
line
50
50
25
50
mV
Load Regulation (Note 2)
5.0 mA
I
O
1.0 A
5.0 mA
I
O
1.5 A (T
J
= +25
C)
250 mA
I
O
750 mA (T
J
= +25
C)
Reg
load
50
50
25
mV
Output Voltage
7.0
V
in
20 Vdc, 5.0 mA
I
O
1.0 A, P
D
15 W
V
O
4.75
5.25
Vdc
Quiescent Current
I
O
= 1.0 A
T
J
= +25
C
I
B
4.0
8.5
8.0
mA
Quiescent Current Change
7.0
V
in
25 Vdc, I
O
= 500 mA
5.0 mA
I
O
1.0 A, V
in
= 10 V
7.5
V
in
20 Vdc, I
O
= 1.0 A
I
B
1.0
0.5
1.0
mA
Ripple Rejection
I
O
= 1.0 A (T
J
= +25
C)
RR
62
80
dB
Dropout Voltage
V
I
V
O
1.7
Vdc
Output Resistance (f = 1.0 kHz)
r
O
2.0
m
Short Circuit Current Limit (T
J
= +25
C)
I
SC
2.0
A
Output Noise Voltage (T
A
= +25
C)
10 Hz
f
100 kHz
V
n
40
V
Average Temperature Coefficient of Output Voltage
I
O
= 5.0 mA
TCV
O
0.6
mV/
C
Peak Output Current (T
J
= +25
C)
I
O
2.4
A
Input Voltage to Maintain Line Regulation (T
J
= +25
C)
I
O
= 1.0 A
7.3
Vdc
NOTES: 1. T
low
to T
high
= 0
to +125
C
2. Load and line regulation are specified at constant junction temperature. Changes in V
O
due to heating effects must be taken into account separately.
Pulse testing with low duty cycle is used.
DEFINITIONS
Line Regulation The change in output voltage for a
change in the input voltage. The measurement is made
under conditions of low dissipation or by using pulse
techniques such that the average chip temperature is not
significantly affected.
Load Regulation The change in output voltage for a
change in load current at constant chip temperature.
Maximum Power Dissipation The maximum total
device dissipation for which the regulator will operate
within specifications.
Quiescent Current That part of the input current that is
not delivered to the load.
Output Noise Voltage The rms AC voltage at the output,
with constant load and no input ripple, measured over a
specified frequency range.
LM340, A Series
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4
LM340A5.0
ELECTRICAL CHARACTERISTICS
(V
in
= 10 V, I
O
= 1.0 A, T
J
= T
low
to T
high
[Note 1], unless otherwise noted.)
Characteristics
Symbol
Min
Typ
Max
Unit
Output Voltage (T
J
= +25
C)
I
O
= 5.0 mA to 1.0 A
V
O
4.9
5.0
5.1
Vdc
Line Regulation
7.5 Vdc to 20 Vdc, I
O
= 500 mA
7.3 Vdc to 25 Vdc (T
J
= +25
C)
8.0 Vdc to 12 Vdc
8.0 Vdc to 12 Vdc (T
J
= +25
C)
Reg
line
3.0
10
10
12
4.0
mV
Load Regulation
5.0 mA
I
O
1.0 A
5.0 mA
I
O
1.5 A (T
J
= +25
C)
250 mA
I
O
750 mA (T
J
= +25
C)
Reg
load
25
25
15
mV
Output Voltage
7.5
V
in
20 Vdc, 5.0 mA
I
O
1.0 A, P
D
15 W
V
O
4.8
5.2
Vdc
Quiescent Current
T
J
= +25
C
I
B
3.5
6.5
6.0
mA
Quiescent Current Change
5.0 mA
I
O
1.0 A, V
in
= 10 V
8.0
V
in
25 Vdc, I
O
= 500 mA
7.5
V
in
20 Vdc, I
O
= 1.0 A (T
J
= +25
C)
I
B
0.5
0.8
0.8
mA
Ripple Rejection
8.0
V
in
18 Vdc, f = 120 Hz
I
O
= 500 mA
I
O
= 1.0 A (T
J
= +25
C)
RR
68
68
80
dB
Dropout Voltage
V
I
V
O
1.7
Vdc
Output Resistance (f = 1.0 kHz)
r
O
2.0
m
Short Circuit Current Limit (T
J
= +25
C)
I
SC
2.0
A
Output Noise Voltage (T
A
= +25
C)
10 Hz
f
100 kHz
V
n
40
V
Average Temperature Coefficient of Output Voltage
I
O
= 5.0 mA
TCV
O
0.6
mV/
C
Peak Output Current (T
J
= +25
C)
I
O
2.4
A
Input Voltage to Maintain Line Regulation (T
J
= +25
C)
I
O
= 1.0 A
7.3
Vdc
NOTE: 1. T
low
to T
high
= 0
to +125
C
LM340, A Series
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5
LM3406.0
ELECTRICAL CHARACTERISTICS
(V
in
= 11 V, I
O
= 500 mA, T
J
= T
low
to T
high
[Note 1], unless otherwise noted.)
Characteristics
Symbol
Min
Typ
Max
Unit
Output Voltage (T
J
= +25
C)
I
O
= 5.0 mA to 1.0 A
V
O
5.75
6.0
6.25
Vdc
Line Regulation
9.0 Vdc to 21 Vdc
8.0 Vdc to 25 Vdc (T
J
= +25
C)
9.0 Vdc to 13 Vdc, I
O
= 1.0 A
8.3 Vdc to 21 Vdc, I
O
= 1.0 A (T
J
= +25
C)
Reg
line
60
60
30
60
mV
Load Regulation
5.0 mA
I
O
1.0 A
5.0 mA
I
O
1.5 A (T
J
= +25
C)
250 mA
I
O
750 mA (T
J
= +25
C)
Reg
load
60
60
30
mV
Output Voltage
8.0
V
in
21 Vdc, 6.0 mA
I
O
1.0 A, P
D
15 W
V
O
5.7
6.3
Vdc
Quiescent Current
I
O
= 1.0 A
T
J
= +25
C
I
B
4.0
8.5
8.0
mA
Quiescent Current Change
8.0
V
in
25 Vdc, I
O
= 500 mA
5.0 mA
I
O
1.0 A, V
in
= 11 V
8.6
V
in
21 Vdc, I
O
= 1.0 A
I
B
1.0
0.5
1.0
mA
Ripple Rejection
I
O
= 1.0 A (T
J
= +25
C)
RR
59
78
dB
Dropout Voltage
V
I
V
O
1.7
Vdc
Output Resistance (f = 1.0 kHz)
r
O
2.0
m
Short Circuit Current Limit (T
J
= +25
C)
I
SC
1.9
A
Output Noise Voltage (T
A
= +25
C)
10 Hz
f
100 kHz
V
n
45
V
Average Temperature Coefficient of Output Voltage
I
O
= 5.0 mA
TCV
O
0.7
mV/
C
Peak Output Current (T
J
= +25
C)
I
O
2.4
A
Input Voltage to Maintain Line Regulation (T
J
= +25
C)
I
O
= 1.0 A
8.3
Vdc
NOTE: 1. T
low
to T
high
= 0
to +125
C
LM340, A Series
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6
LM3408.0
ELECTRICAL CHARACTERISTICS
(V
in
= 14 V, I
O
= 500 mA, T
J
= T
low
to T
high
[Note 1], unless otherwise noted.)
Characteristics
Symbol
Min
Typ
Max
Unit
Output Voltage (T
J
= +25
C)
I
O
= 5.0 mA to 1.0 A
V
O
7.7
8.0
8.3
Vdc
Line Regulation
11 Vdc to 23 Vdc
10.5 Vdc to 25 Vdc (T
J
= +25
C)
11 Vdc to 17 Vdc, I
O
= 1.0 A
10.5 Vdc to 23 Vdc, I
O
= 1.0 A (T
J
= +25
C)
Reg
line
80
80
40
80
mV
Load Regulation
5.0 mA
I
O
1.0 A
5.0 mA
I
O
1.5 A (T
J
= +25
C)
250 mA
I
O
750 mA (T
J
= +25
C)
Reg
load
80
80
40
mV
Output Voltage
10.5
V
in
23 Vdc, 5.0 mA
I
O
1.0 A, P
D
15 W
V
O
7.6
8.4
Vdc
Quiescent Current
I
O
= 1.0 A
T
J
= +25
C
I
B
4.0
8.5
8.0
mA
Quiescent Current Change
10.5
V
in
25 Vdc, I
O
= 500 mA
5.0 mA
I
O
1.0 A, V
in
= 14 V
10.6
V
in
23 Vdc, I
O
= 1.0 A
I
B
1.0
0.5
1.0
mA
Ripple Rejection
I
O
= 1.0 A (T
J
= +25
C)
RR
56
76
dB
Dropout Voltage
V
I
V
O
1.7
Vdc
Output Resistance (f = 1.0 kHz)
r
O
2.0
m
Short Circuit Current Limit (T
J
= +25
C)
I
SC
1.5
A
Output Noise Voltage (T
A
= +25
C)
10 Hz
f
100 kHz
V
n
52
V
Average Temperature Coefficient of Output Voltage
I
O
= 5.0 mA
TCV
O
1.0
mV/
C
Peak Output Current (T
J
= +25
C)
I
O
2.4
A
Input Voltage to Maintain Line Regulation (T
J
= +25
C)
I
O
= 1.0 A
10.5
Vdc
NOTE: 1. T
low
to T
high
= 0
to +125
C
LM340, A Series
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7
LM34012
ELECTRICAL CHARACTERISTICS
(V
in
= 19 V, I
O
= 500 mA, T
J
= T
low
to T
high
[Note 1], unless otherwise noted.)
Characteristics
Symbol
Min
Typ
Max
Unit
Output Voltage (T
J
= +25
C)
I
O
= 5.0 mA to 1.0 A
V
O
11.5
12
12.5
Vdc
Line Regulation (Note 2)
15 Vdc to 27 Vdc
14.6 Vdc to 30 Vdc (T
J
= +25
C)
16 Vdc to 22 Vdc, I
O
= 1.0 A
14.6 Vdc to 27 Vdc, I
O
= 1.0 A (T
J
= +25
C)
Reg
line
120
120
60
120
mV
Load Regulation (Note 2)
5.0 mA
I
O
1.0 A
5.0 mA
I
O
1.5 A (T
J
= +25
C)
250 mA
I
O
750 mA (T
J
= +25
C)
Reg
load
120
120
60
mV
Output Voltage
14.5
V
in
27 Vdc, 5.0 mA
I
O
1.0 A, P
D
15 W
V
O
11.4
12.6
Vdc
Quiescent Current
I
O
= 1.0 A
T
J
= +25
C
I
B
4.0
8.5
8.0
mA
Quiescent Current Change
14.5
V
in
30 Vdc, I
O
= 500 mA
5.0 mA
I
O
1.0 A, V
in
= 19 V
14.8
V
in
27 Vdc, I
O
= 1.0 A
I
B
1.0
0.5
1.0
mA
Ripple Rejection
I
O
= 1.0 A (T
J
= +25
C)
RR
55
72
dB
Dropout Voltage
V
I
V
O
1.7
Vdc
Output Resistance (f = 1.0 kHz)
r
O
2.0
m
Short Circuit Current Limit (T
J
= +25
C)
I
SC
1.1
A
Output Noise Voltage (T
A
= +25
C)
10 Hz
f
100 kHz
V
n
75
V
Average Temperature Coefficient of Output Voltage
I
O
= 5.0 mA
TCV
O
1.5
mV/
C
Peak Output Current (T
J
= +25
C)
I
O
2.4
A
Input Voltage to Maintain Line Regulation (T
J
= +25
C)
I
O
= 1.0 A
14.6
Vdc
NOTES: 1. T
low
to T
high
= 0
to +125
C
2. Load and line regulation are specified at constant junction temperature. Changes in V
O
due to heating effects must be taken into account separately.
Pulse testing with low duty cycle is used.
LM340, A Series
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8
LM340A12
ELECTRICAL CHARACTERISTICS
(V
in
= 19 V, I
O
= 1.0 mA, T
J
= T
low
to T
high
[Note 1], unless otherwise noted.)
Characteristics
Symbol
Min
Typ
Max
Unit
Output Voltage (T
J
= +25
C)
I
O
= 5.0 mA to 1.0 A
V
O
11.75
12
12.25
Vdc
Line Regulation
14.8 Vdc to 27 Vdc, I
O
= 500 mA
14.5 Vdc to 30 Vdc (T
J
= +25
C)
16 Vdc to 22 Vdc
16 Vdc to 22 Vdc (T
J
= +25
C)
Reg
line
4.0
18
18
30
9.0
mV
Load Regulation
5.0 mA
I
O
1.0 A
5.0 mA
I
O
1.5 A (T
J
= +25
C)
250 mA
I
O
750 mA (T
J
= +25
C)
Reg
load
60
32
19
mV
Output Voltage
14.8
V
in
27 Vdc, 5.0 mA
I
O
1.0 A, P
D
15 W
V
O
11.5
12.5
Vdc
Quiescent Current
T
J
= +25
C
I
B
3.5
6.5
6.0
mA
Quiescent Current Change
5.0 mA
I
O
1.0 A, V
in
= 19 V
15
V
in
30 Vdc, I
O
= 500 mA
14.8
V
in
27 Vdc, I
O
= 1.0 A(T
J
= +25
C)
I
B
0.5
0.8
0.8
mA
Ripple Rejection
15
V
in
25 Vdc, f = 120 Hz
I
O
= 500 mA
I
O
= 1.0 A (T
J
= +25
C)
RR
61
61
72
dB
Dropout Voltage
V
I
V
O
1.7
Vdc
Output Resistance (f = 1.0 kHz)
r
O
2.0
m
Short Circuit Current Limit (T
J
= +25
C)
I
SC
1.1
A
Output Noise Voltage (T
A
= +25
C)
10 Hz
f
100 kHz
V
n
75
V
Average Temperature Coefficient of Output Voltage
I
O
= 5.0 mA
TCV
O
1.5
mV/
C
Peak Output Current (T
J
= +25
C)
I
O
2.4
A
Input Voltage to Maintain Line Regulation (T
J
= +25
C)
14.5
Vdc
NOTE: 1. T
low
to T
high
= 0
to +125
C
LM340, A Series
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9
LM34015
ELECTRICAL CHARACTERISTICS
(V
in
= 23 V, I
O
= 500 mA, T
J
= T
low
to T
high
[Note 1], unless otherwise noted.)
Characteristics
Symbol
Min
Typ
Max
Unit
Output Voltage (T
J
= +25
C)
I
O
= 5.0 mA to 1.0 A
V
O
14.4
15
15.6
Vdc
Line Regulation (Note 2)
18.5 Vdc to 30 Vdc
17.5 Vdc to 30 Vdc (T
J
= +25
C)
20 Vdc to 26 Vdc, I
O
= 1.0 A
17.7 Vdc to 30 Vdc, I
O
= 1.0 A (T
J
= +25
C)
Reg
line
150
150
75
150
mV
Load Regulation (Note 2)
5.0 mA
I
O
1.0 A
5.0 mA
I
O
1.5 A (T
J
= +25
C)
250 mA
I
O
750 mA (T
J
= +25
C)
Reg
load
150
150
75
mV
Output Voltage
17.5
V
in
30 Vdc, 5.0 mA
I
O
1.0 A, P
D
15 W
V
O
14.25
15.75
Vdc
Quiescent Current
I
O
= 1.0 A
T
J
= +25
C
I
B
4.0
8.5
8.0
mA
Quiescent Current Change
17.5
V
in
30 Vdc, I
O
= 500 mA
5.0 mA
I
O
1.0 A, V
in
= 23 V
17.9
V
in
30 Vdc, I
O
= 1.0 A
I
B
1.0
0.5
1.0
mA
Ripple Rejection
I
O
= 1.0 mA (T
J
= +25
C)
RR
54
70
dB
Dropout Voltage
V
I
V
O
1.7
Vdc
Output Resistance (f = 1.0 kHz)
r
O
2.0
m
Short Circuit Current Limit (T
J
= +25
C)
I
SC
800
A
Output Noise Voltage (T
A
= +25
C)
10 Hz
f
100 kHz
V
n
90
V
Average Temperature Coefficient of Output Voltage
I
O
= 5.0 mA
TCV
O
1.8
mV/
C
Peak Output Current (T
J
= +25
C)
I
O
2.4
A
Input Voltage to Maintain Line Regulation (T
J
= +25
C)
I
O
= 1.0 A
17.7
Vdc
NOTES: 1. T
low
to T
high
= 0
to +125
C
2. Load and line regulation are specified at constant junction temperature. Changes in V
O
due to heating effects must be taken into account separately.
Pulse testing with low duty cycle is used.
LM340, A Series
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10
LM340A15
ELECTRICAL CHARACTERISTICS
(V
in
= 23 V, I
O
= 1.0 mA, T
J
= T
low
to T
high
[Note 1], unless otherwise noted.)
Characteristics
Symbol
Min
Typ
Max
Unit
Output Voltage (T
J
= +25
C)
I
O
= 5.0 mA to 1.0 A
V
O
14.7
15
15.3
Vdc
Line Regulation
17.9 Vdc to 30 Vdc, I
O
= 500 mA
17.5 Vdc to 30 Vdc (T
J
= +25
C)
20 Vdc to 26 Vdc, I
O
= 1.0 A
20 Vdc to 26 Vdc, I
O
= 1.0 A (T
J
= +25
C)
Reg
line
4.0
22
22
30
10
mV
Load Regulation
5.0 mA
I
O
1.0 A
5.0 mA
I
O
1.5 A (T
J
= +25
C)
250 mA
I
O
750 mA (T
J
= +25
C)
Reg
load
12
75
35
21
mV
Output Voltage
17.9
V
in
30 Vdc, 5.0 mA
I
O
1.0 A, P
D
15 W
V
O
14.4
15.6
Vdc
Quiescent Current
T
J
= +25
C
I
B
3.5
6.5
6.0
mA
Quiescent Current Change
5.0 mA
I
O
1.0 A, V
in
= 23 V
17.9
V
in
30 Vdc, I
O
= 500 mA
17.9
V
in
30 Vdc, I
O
= 1.0 A (T
J
= +25
C)
I
B
0.5
0.8
0.8
mA
Ripple Rejection
18.5
V
in
28.5 Vdc, f = 120 Hz
I
O
= 500 mA
I
O
= 1.0 A (T
J
= +25
C)
RR
60
60
70
dB
Dropout Voltage
V
I
V
O
1.7
Vdc
Output Resistance (f = 1.0 kHz)
r
O
2.0
m
Short Circuit Current Limit (T
J
= +25
C)
I
SC
800
A
Output Noise Voltage (T
A
= +25
C)
10 Hz
f
100 kHz
V
n
90
V
Average Temperature Coefficient of Output Voltage
I
O
= 5.0 mA
TCV
O
1.8
mV/
C
Peak Output Current (T
J
= +25
C)
I
O
2.4
A
Input Voltage to Maintain Line Regulation (T
J
= +25
C)
17.5
Vdc
NOTE: 1. T
low
to T
high
= 0
to +125
C
LM340, A Series
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11
LM34018
ELECTRICAL CHARACTERISTICS
(V
in
= 27 V, I
O
= 500 mA, T
J
= T
low
to T
high
[Note 1], unless otherwise noted.)
Characteristics
Symbol
Min
Typ
Max
Unit
Output Voltage (T
J
= +25
C)
I
O
= 5.0 mA to 1.0 A
V
O
17.3
18
18.7
Vdc
Line Regulation
21.5 Vdc to 33 Vdc
21 Vdc to 33 Vdc (T
J
= +25
C)
24 Vdc to 30 Vdc, I
O
= 1.0 A
21 Vdc to 33 Vdc, I
O
= 1.0 A (T
J
= +25
C)
Reg
line
180
180
90
180
mV
Load Regulation
5.0 mA
I
O
1.0 A
5.0 mA
I
O
1.5 A (T
J
= +25
C)
250 mA
I
O
750 mA (T
J
= +25
C)
Reg
load
180
180
90
mV
Output Voltage
21
V
in
33 Vdc, 5.0 mA
I
O
1.0 A, P
D
15 W
V
O
17.1
18.9
Vdc
Quiescent Current
I
O
= 1.0 A
T
J
= +25
C
I
B
4.0
8.5
8.0
mA
Quiescent Current Change
21
V
in
33 Vdc, I
O
= 500 mA
5.0 mA
I
O
1.0 A, V
in
= 27 V
21
V
in
33 Vdc, I
O
= 1.0 A
I
B
1.0
0.5
1.0
mA
Ripple Rejection
I
O
= 1.0 mA (T
J
= +25
C)
RR
53
69
dB
Dropout Voltage
V
I
V
O
1.7
Vdc
Output Resistance (f = 1.0 kHz)
r
O
2.0
m
Short Circuit Current Limit (T
J
= +25
C)
I
SC
500
A
Output Noise Voltage (T
A
= +25
C)
10 Hz
f
100 kHz
V
n
110
V
Average Temperature Coefficient of Output Voltage
I
O
= 5.0 mA
TCV
O
2.3
mV/
C
Peak Output Current (T
J
= +25
C)
I
O
2.4
A
Input Voltage to Maintain Line Regulation (T
J
= +25
C)
I
O
= 1.0 A
21
Vdc
NOTE: 1. T
low
to T
high
= 0
to +125
C
LM340, A Series
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12
LM34024
ELECTRICAL CHARACTERISTICS
(V
in
= 33 V, I
O
= 500 mA, T
J
= T
low
to T
high
[Note 1], unless otherwise noted.)
Characteristics
Symbol
Min
Typ
Max
Unit
Output Voltage (T
J
= +25
C)
I
O
= 5.0 mA to 1.0 A
V
O
23
24
25
Vdc
Line Regulation
28 Vdc to 38 Vdc
27 Vdc to 38 Vdc (T
J
= +25
C)
30 Vdc to 36 Vdc, I
O
= 1.0 A
27.1 Vdc to 38 Vdc, I
O
= 1.0 A (T
J
= +25
C)
Reg
line
240
240
120
240
mV
Load Regulation
5.0 mA
I
O
1.0 A
5.0 mA
I
O
1.5 A (T
J
= +25
C)
250 mA
I
O
750 mA (T
J
= +25
C)
Reg
load
240
240
120
mV
Output Voltage
27
V
in
38 Vdc, 5.0 mA
I
O
1.0 A, P
D
15 W
V
O
22.8
25.2
Vdc
Quiescent Current
I
O
= 1.0 A
T
J
= +25
C
I
B
4.0
8.5
8.0
mA
Quiescent Current Change
27
V
in
38 Vdc, I
O
= 500 mA
5.0 mA
I
O
1.0 A, V
in
= 33 V
27.3
V
in
38 Vdc, I
O
= 1.0 A
I
B
1.0
0.5
1.0
mA
Ripple Rejection
I
O
= 1.0 mA (T
J
= +25
C)
RR
50
66
dB
Dropout Voltage
V
I
V
O
1.7
Vdc
Output Resistance (f = 1.0 kHz)
r
O
2.0
m
Short Circuit Current Limit (T
J
= +25
C)
I
SC
200
A
Output Noise Voltage (T
A
= +25
C)
10 Hz
f
100 kHz
V
n
170
V
Average Temperature Coefficient of Output Voltage
I
O
= 5.0 m
A
TCV
O
3.0
mV/
C
Peak Output Current (T
J
= +25
C)
I
O
2.4
A
Input Voltage to Maintain Line Regulation (T
J
= +25
C)
I
O
= 1.0 A
27.1
Vdc
NOTE: 1. T
low
to T
high
= 0
to +125
C
LM340, A Series
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13
VOLTAGE REGULATOR PERFORMANCE
The performance of a voltage regulator is specified by its
immunity to changes in load, input voltage, power
dissipation, and temperature. Line and load regulation are
tested with a pulse of short duration (< 100
s) and are
strictly a function of electrical gain. However, pulse widths
of longer duration (> 1.0 ms) are sufficient to affect
temperature gradients across the die. These temperature
gradients can cause a change in the output voltage, in
addition to changes caused by line and load regulation.
Longer pulse widths and thermal gradients make it
desirable to specify thermal regulation.
Thermal regulation is defined as the change in output
voltage caused by a change in dissipated power for a
specified time, and is expressed as a percentage output
voltage change per watt. The change in dissipated power
can be caused by a change in either input voltage or the load
current. Thermal regulation is a function of IC layout and
die attach techniques, and usually occurs within 10 ms of
a change in power dissipation. After 10 ms, additional
changes in the output voltage are due to the temperature
coefficient of the device.
Figure 1 shows the line and thermal regulation response
of a typical LM340AT5.0 to a 10 W input pulse. The
variation of the output voltage due to line regulation is
labeled and the thermal regulation component is labeled
. Figure 2 shows the load and thermal regulation response
of a typical LM340AT5.0 to a 15 W load pulse. The output
voltage variation due to load regulation is labeled and the
thermal regulation component is labeled .
2
1
2
1
V out
, OUTPUT
I out
, OUTPUT
V out
, OUTPUT
V in
, INPUT
V
out
= 5.0 V
V
in
= 7.5 V
I
out
= 1.0 A
C
O
= 0
T
J
= 25
C
V
in
- V
out
= 5.0 V
I
out
= 100 mA
Figure 1. Line and Thermal Regulation
Figure 2. Load and Thermal Regulation
LM340AT-5.0
V
out
= 5.0 V
V
in
= 15 V
I
out
= 0 A
1.5 A
0 A
= Reg
line
= 4.4 mV
t, TIME (2.0 ms/DIV)
CURRENT (A)
VOL
T
AGE DEVIA
TION (V)
(2.0 mV/DIV)
1
2
2.0
0
LM340AT-5.0
V
out
= 5.0 V
V
in
= 8.0 V
18 V
8.0 V
I
out
= 1.0 A
= Reg
line
= 2.4 mV
t, TIME (2.0 ms/DIV)
VOL
T
AGE (V)
VOL
T
AGE DEVIA
TION (V)
(2.0 mV/DIV)
1
2
18 V
8.0 V
2
2
Figure 3. Temperature Stability
Figure 4. Output Impedance
1.02
1.00
0.98
-90
-50
-10
30
70
110
150
190
T
J
, JUNCTION TEMPERATURE (
C)
NORMALIZED OUTPUT VOL
T
AGE
10
0
10
-1
10
-2
10
-3
10
-4
1.0
10
100 1.0 k
10 k
100 k
1.0 M 10 M 100 M
f, FREQUENCY (Hz)
1.01
0.99
= Reg
therm
= 0.0030% V
O
/W
= Reg
therm
= 0.0020% V
O
/W
Z O
, OUTPUT IMPEDANCE (
)
LM340, A Series
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14
I out
, OUTPUT CURRENT (A)
V in
-V
out
, INPUT-OUTPUT VOLT
AGE
DIFFERENTIAL
(V)
I B
, QUIESCENT CURRENT (mA)
I B
, QUIESCENT CURRENT (mA)
V
out
= 5.0 V
V
in
= 10 V
V
in
= 10 V
C
O
= 0
f = 120 Hz
T
J
= 25
C
I
out
= 1.5 A
V
out
= 5.0 V
V
in
= 10 V
C
O
= 0
T
J
= 25
C
Figure 5. Ripple Rejection versus Frequency
Figure 6. Ripple Rejection versus Output Current
Figure 7. Quiescent Current versus
Input Voltage
Figure 8. Quiescent Current versus
Output Current
Figure 9. Dropout Voltage
Figure 10. Peak Output Current
100
80
60
40
20
1.0
10
100
1.0 k
10 k
100 k
1.0 M 10 M 100 M
f, FREQUENCY (Hz)
RR, RIPPLE REJECTION (dB)
I
out
= 50 mA
4.0
3.0
2.0
1.0
0
0
10
20
30
40
V
in
, INPUT VOLTAGE (Vdc)
5.0
4.0
3.0
2.0
1.0
0
0.01
0.1
1.0
10
I
out
, OUTPUT CURRENT (A)
100
80
60
40
30
0.01
0.1
1.0
10
I
out
, OUTPUT CURRENT (A)
RR, RIPPLE REJECTION (dB)
T
J
= 25
C
V
out
= 5.0 V
I
out
= 1.0 A
T
J
= 25
C
V
in
- V
out
= 5.0 V
2.5
2.0
1.5
1.0
0.5
0
-75
-50
-25
0
25
50
75
100
125
T
A
, AMBIENT TEMPERATURE (
C)
V
out
= 100 mV
I
O
= 1.0 A
I
O
= 500 mA
I
O
= 10 mA
4.0
3.0
2.0
1.0
0
0
10
20
30
40
V
in
-V
out
, INPUT-OUTPUT VOLTAGE DIFFERENTIAL (V)
T
J
= 25
C
LM340, A Series
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15
V out
, OUTPUT VOL
T
AGE
DEVIA
TION (V)
I out
, OUTPUT
V out
, OUTPUT VOL
T
AGE
DEVIA
TION (V)
V in
, INPUT VOL
T
AGE
CHANGE (V)
-0.1
Figure 11. Line Transient Response
Figure 12. Load Transient Response
Figure 13. Worst Case Power Dissipation
versus Ambient Temperature (Case 221A)
0
10
20
30
40
0.8
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
1.0
0.5
0
t, TIME (
s)
V
out
= 5.0 V
I
out
= 150 mA
C
O
= 0
T
J
= 25
C
1.0
CURRENT (A)
0
10
20
30
40
t, TIME (
s)
V
out
= 5.0 V
V
in
= 10 V
C
O
= 0
T
J
= 25
C
0.3
0.2
0.1
0
-0.2
-0.3
1.5
0.5
0
20
16
12
8.0
4.0
0
-50
-25
0
25
50
75
100
125
150
T
A
, AMBIENT TEMPERATURE (
C)
, POWER DISSIP
A
TION (W)
DP
JC
= 5
C/W
JA
= 65
C/W
T
J(max)
= 150
C
HS
= 0
C/W
HS
= 5
C/W
HS
= 15
C/W
No Heatsink
LM340, A Series
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16
APPLICATIONS INFORMATION
Design Considerations
The LM340, A series of fixed voltage regulators are
designed with Thermal Overload Protection that shuts
down the circuit when subjected to an excessive power
overload condition, Internal Short Circuit Protection that
limits the maximum current the circuit will pass, and
Output Transistor SafeArea Compensation that reduces
the output short circuit current as the voltage across the pass
transistor is increased.
In many low current applications, compensation
capacitors are not required. However, it is recommended
that the regulator input be bypassed with a capacitor if the
regulator is connected to the power supply filter with long
wire lengths, or if the output load capacitance is large. An
input bypass capacitor should be selected to provide good
highfrequency characteristics to insure stable operation
under all load conditions. A 0.33
F or larger tantalum,
mylar, or other capacitor having low internal impedance at
high frequencies should be chosen. The bypass capacitor
should be mounted with the shortest possible leads directly
across the regulators input terminals. Normally good
construction techniques should be used to minimize ground
loops and lead resistance drops since the regulator has no
external sense lead.
Figure 14. Current Regulator
Figure 15. Adjustable Output Regulator
Figure 16. Current Boost Regulator
Figure 17. Short Circuit Protection
5.0 V
R
Input
0.33
F
LM340-5.0
R
I
O
These regulators can also be used as a current source when
connected as above. In order to minimize dissipation the LM340-5.0
is chosen in this application. Resistor R determines the current as
follows:
I
O
=
+ I
Q
I
Q
^ 1.5 mA over line and load changes
For example, a 1 A current source would require R to be a 5
,
10 W resistor and the output voltage compliance would be the input
voltage less 7.0 V.
Constant
Current to
Grounded Load
Input
Output
1k
4
6
7
2
3
-
+
0.1
F
10k
MC1741G
V
out
, 7.0 V to 20 V
V
in
- V
O
2.0 V
The addition of an operational amplifier allows adjustment to higher or
intermediate values while retaining regulation characteristics. The
minimum voltage obtainable with this arrangement is 2.0 V greater
than the regulator voltage.
0.33
F
R
0.1
F
Output
1.0
F
The LM340, A series can be current boosted with a PNP transistor. The
MJ2955 provides current to 5.0 A. Resistor R in conjunction with the V
BE
of the PNP determines when the pass transistor begins conducting; this
circuit is not short circuit proof. Input-output differential voltage
minimum is increased by V
BE
of the pass transistor.
MJ2955 or Equiv
LM340
LM340
Input
R
SC
MJ2955
or Equiv.
Output
R
2N6049
or Equiv.
1.0
F
The circuit of Figure 17 can be modified to provide supply protection
against short circuits by adding a short circuit sense resistor, R
SC
, and
an additional PNP transistor. The current sensing PNP must be able to
handle the short circuit current of the three-terminal regulator.
Therefore, 4.0 A plastic power transistor is specified.
LM340-5.0
Input
LM340, A Series
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17
PACKAGE DIMENSIONS
T SUFFIX
PLASTIC PACKAGE
CASE 221A09
ISSUE AA
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
3. DIMENSION Z DEFINES A ZONE WHERE ALL
BODY AND LEAD IRREGULARITIES ARE
ALLOWED.
DIM
MIN
MAX
MIN
MAX
MILLIMETERS
INCHES
A
0.570
0.620
14.48
15.75
B
0.380
0.405
9.66
10.28
C
0.160
0.190
4.07
4.82
D
0.025
0.035
0.64
0.88
F
0.142
0.147
3.61
3.73
G
0.095
0.105
2.42
2.66
H
0.110
0.155
2.80
3.93
J
0.018
0.025
0.46
0.64
K
0.500
0.562
12.70
14.27
L
0.045
0.060
1.15
1.52
N
0.190
0.210
4.83
5.33
Q
0.100
0.120
2.54
3.04
R
0.080
0.110
2.04
2.79
S
0.045
0.055
1.15
1.39
T
0.235
0.255
5.97
6.47
U
0.000
0.050
0.00
1.27
V
0.045
---
1.15
---
Z
---
0.080
---
2.04
B
Q
H
Z
L
V
G
N
A
K
F
1 2 3
4
D
SEATING
PLANE
T
C
S
T
U
R
J
LM340, A Series
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18
Notes
LM340, A Series
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19
Notes
LM340, A Series
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20
ON Semiconductor and are trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes
without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular
purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability,
including without limitation special, consequential or incidental damages. "Typical" parameters which may be provided in SCILLC data sheets and/or
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