LM2940/LM2940C
LM2940/LM2940C 1A Low Dropout Regulator
General Description
The LM2940/LM2940C positive voltage regulator features
the ability to source 1A of output current with a dropout
voltage of typically 0.5V and a maximum of 1V over the
entire temperature range. Furthermore, a quiescent current
reduction circuit has been included which reduces the
ground current when the differential between the input volt-
age and the output voltage exceeds approximately 3V. The
quiescent current with 1A of output current and an input-
output differential of 5V is therefore only 30 mA. Higher
quiescent currents only exist when the regulator is in the
dropout mode (V
IN
− V
OUT
≤
3V).
Designed also for vehicular applications, the LM2940/
LM2940C and all regulated circuitry are protected from re-
verse battery installations or 2-battery jumps. During line
transients, such as load dump when the input voltage can
momentarily exceed the specified maximum operating volt-
age, the regulator will automatically shut down to protect
both the internal circuits and the load. The LM2940/
LM2940C cannot be harmed by temporary mirror-image in-
sertion. Familiar regulator features such as short circuit and
thermal overload protection are also provided.
Features
n
n
n
n
n
n
n
Dropout voltage typically 0.5V
@
I
O
= 1A
Output current in excess of 1A
Output voltage trimmed before assembly
Reverse battery protection
Internal short circuit current limit
Mirror image insertion protection
P
+
Product Enhancement tested
Typical Application
00882203
*
Required if regulator is located far from power supply filter.
**
C
OUT
must be at least 22 µF to maintain stability. May be increased without bound to maintain regulation during transients. Locate as close as possible
to the regulator. This capacitor must be rated over the same operating temperature range as the regulator and the ESR is critical; see curve.
Connection Diagrams
(TO-220) Plastic Package
3-Lead SOT-223
Front View
Front View
http://www.hgsemi.com.cn
1
2015 MAR
LM2940/LM2940C
Connection Diagrams
16-Lead Dual-in-Line Package (J)
16-Lead Ceramic Surface-Mount Package (WG)
Top View
Top View
(TO-263) Surface-Mount Package
8-Lead LLP
Top View
Top View
Side View
Pin 2 and pin 7 are fused to center DAP
Pin 5 ans 6 need to be tied together on PCB board
http://www.hgsemi.com.cn
2
2015 MAR
LM2940/LM2940C
Absolute Maximum Ratings
LM2940S, T, MP
≤
100 ms
LM2940CS, T
≤
1 ms
Internal Power Dissipation
(Note 2)
Maximum Junction Temperature
Storage Temperature Range
TO-220 (T) Package
Lead Temperature, Time for Wave Soldering
260˚C, 10s
Internally Limited
150˚C
−65˚C
≤
T
J
≤
+150˚C
(Note 1)
If Military/Aerospace specified devices are required,
please Distributors for availability and specifications.
60V
45V
Input Voltage
Temperature Range
LM2940T, LM2940S
LM2940CT, LM2940CS
LM2940IMP
LM2940J, LM2940WG
LM2940LD
−40˚C
≤
T
J
≤
125˚C
0˚C
≤
T
J
≤
125˚C
−40˚C
≤
T
J
≤
85˚C
−55˚C
≤
T
J
≤
125˚C
−40˚C
≤
T
J
≤
125˚C
26V
TO-263 (S) Package
SOT-223 (MP) Package
ESD Susceptibility (Note 3)
260˚C, 4s
260˚C, 4s
2 kV
Operating Conditions
(Note 1)
Electrical Characteristics
V
IN
= V
O
+ 5V, I
O
= 1A, C
O
= 22 µF, unless otherwise specified.
Boldface limits apply over the entire operating tempera-
ture range of the indicated device.
All other specifications apply for T
A
= T
J
= 25˚C.
Output Voltage (V
O
)
Parameter
Conditions
Typ
5V
LM2940
Limit
(Note 4)
Output Voltage
Line Regulation
Load Regulation
5 mA
≤
I
O
≤
1A
V
O
+ 2V
≤
V
IN
≤
26V,
I
O
= 5 mA
50 mA
≤
I
O
≤
1A
LM2940, LM2940/883
LM2940C
Output
Impedance
Quiescent
Current
100 mADC and
20 mArms,
f
O
= 120 Hz
V
O
+2V
≤
V
IN
≤
26V,
I
O
= 5 mA
LM2940, LM2940/883
LM2940C
V
IN
= V
O
+ 5V,
I
O
= 1A
Output Noise
Voltage
Ripple Rejection
10 Hz − 100 kHz,
I
O
= 5 mA
f
O
= 120 Hz, 1 V
rms
,
I
O
= 100 mA
LM2940
LM2940C
f
O
= 1 kHz, 1 V
rms
,
I
O
= 5 mA
Long Term
Stability
Dropout Voltage
Short Circuit
Current
I
O
= 1A
I
O
= 100 mA
(Note 6)
0.5
110
1.9
0.8/1.0
150/200
1.6
0.7/1.0
150/200
1.5/1.3
0.5
110
1.9
0.8/1.0
150/200
1.6
0.7/1.0
150/200
1.6/1.3
20
32
mV/
1000 Hr
V
MAX
mV
MAX
A
MIN
72
72
60/54
60
60/50
66
66
54/48
54
54/48
dB
MIN
dB
MIN
150
700/700
240
1000/1000
µV
rms
10
10
30
15/20
15
45/60
50/60
30
45/60
50/60
mA
MAX
15/20
10
15/20
15/20
mA
MAX
35
1000/1000
55
1000/1000
mΩ
35
35
50/80
50
50/100
55
55
80/130
80
80/130
mV
MAX
5.00
20
4.85/4.75
5.15/5.25
50
LM2940/883
Limit
(Note 5)
4.85/4.75
5.15/5.25
40/50
20
8.00
Typ
8V
LM2940
Limit
(Note 4)
7.76/7.60
8.24/8.40
80
LM2940/883
Limit
(Note 5)
7.76/7.60
8.24/8.40
50/80
V
MIN
V
MAX
mV
MAX
Units
6.25V
≤
V
IN
≤
26V
9.4V
≤
V
IN
≤
26V
http://www.hgsemi.com.cn
3
2015 MAR
LM2940/LM2940C
Electrical Characteristics
Output Voltage (V
O
)
Parameter
Maximum Line
Transient
Conditions
R
O
= 100Ω
LM2940, T
≤
100 ms
LM2940/883, T
≤
20 ms
LM2940C, T
≤
1 ms
Reverse Polarity
DC Input Voltage
Reverse Polarity
Transient Input
Voltage
R
O
= 100Ω
LM2940, LM2940/883
LM2940C
R
O
= 100Ω
LM2940, T
≤
100 ms
LM2940/883, T
≤
20 ms
LM2940C, T
≤
1 ms
−55
−45/−45
−75
−50/−50
−45/−45
−75
−50/−50
−45/−45
V
MIN
−30
−30
−15/−15
−15
−15/−15
−30
−30
−15/−15
−15
−15/−15
V
MIN
55
45
75
60/60
40/40
55
45
75
60/60
40/40
V
MIN
Typ
(Continued)
V
IN
= V
O
+ 5V, I
O
= 1A, C
O
= 22 µF, unless otherwise specified.
Boldface limits apply over the entire operating tempera-
ture range of the indicated device.
All other specifications apply for T
A
= T
J
= 25˚C.
5V
LM2940
Limit
(Note 4)
LM2940/883
Limit
(Note 5)
Typ
8V
LM2940
Limit
(Note 4)
LM2940/883
Limit
(Note 5)
Units
Electrical Characteristics
V
IN
= V
O
+ 5V, I
O
= 1A, C
O
= 22 µF, unless otherwise specified.
Boldface limits apply over the entire operating tempera-
ture range of the indicated device.
All other specifications apply for T
A
= T
J
= 25˚C.
Output Voltage (V
O
)
Parameter
Conditions
Typ
9V
LM2940
Limit
(Note 4)
Output Voltage
Line Regulation
Load Regulation
5 mA
≤
I
O
≤
1A
V
O
+ 2V
≤
V
IN
≤
26V,
I
O
= 5 mA
50 mA
≤
I
O
≤
1A
LM2940
LM2940C
Output Impedance
100 mADC and
20 mArms,
f
O
= 120 Hz
Quiescent
Current
V
O
+2V
≤
V
IN
<
26V,
I
O
= 5 mA
LM2940
LM2940C
Output Noise
Voltage
Ripple Rejection
V
IN
= V
O
+ 5V, I
O
= 1A
10 Hz − 100 kHz,
I
O
= 5 mA
f
O
= 120 Hz, 1 V
rms
,
I
O
= 100 mA
LM2940
LM2940C
Long Term
Stability
Dropout Voltage
I
O
= 1A
I
O
= 100 mA
64
64
34
0.5
110
4
10V
Typ
LM2940
Limit
(Note 4)
11.5V
≤
V
IN
≤
26V
10.00
9.70/9.50
10.30/10.50
20
100
V
MIN
V
MAX
mV
MAX
Units
10.5V
≤
V
IN
≤
26V
9.00
8.73/8.55
9.27/9.45
20
90
60
60
60
90/150
90
65
100/165
mV
MAX
65
mΩ
10
10
30
270
15/20
15
45/60
10
30
300
15/20
45/60
mA
MAX
mA
MAX
µV
rms
52/46
52
63
36
51/45
dB
MIN
mV/
1000 Hr
0.8/1.0
150/200
0.5
110
0.8/1.0
150/200
V
MAX
mV
MAX
http://www.hgsemi.com.cn
2015 MAR
LM2940/LM2940C
Electrical Characteristics
Output Voltage (V
O
)
Parameter
Conditions
Typ
(Continued)
V
IN
= V
O
+ 5V, I
O
= 1A, C
O
= 22 µF, unless otherwise specified.
Boldface limits apply over the entire operating tempera-
ture range of the indicated device.
All other specifications apply for T
A
= T
J
= 25˚C.
9V
LM2940
Limit
(Note 4)
Short Circuit
Current
Maximum Line
Transient
(Note 6)
R
O
= 100Ω
T
≤
100 ms
LM2940
LM2940C
Reverse Polarity
DC Input Voltage
Reverse Polarity
Transient Input
Voltage
R
O
= 100Ω
LM2940
LM2940C
R
O
= 100Ω
T
≤
100 ms
LM2940
LM2940C
−75
−55
−50/−50
−45/−45
−75
−50/−50
V
MIN
−30
−30
−15/−15
−15
−30
−15/−15
V
MIN
75
55
60/60
45
75
60/60
V
MIN
1.9
1.6
1.9
Typ
10V
LM2940
Limit
(Note 4)
1.6
A
MIN
Units
Electrical Characteristics
V
IN
= V
O
+ 5V, I
O
= 1A, C
O
= 22 µF, unless otherwise specified.
Boldface limits apply over the entire operating tempera-
ture range of the indicated device.
All other specifications apply for T
A
= T
J
= 25˚C.
Output Voltage (V
O
)
Parameter
Conditions
Typ
12V
LM2940
Limit
(Note 4)
LM2940/833
Limit
(Note 5)
Typ
15V
LM2940
Limit
(Note 4)
LM2940/833
Limit
(Note 5)
Units
13.6V
≤
V
IN
≤
26V
Output Voltage
Line Regulation
Load Regulation
5 mA
≤
I
O
≤1A
V
O
+ 2V
≤
V
IN
≤
26V,
I
O
= 5 mA
50 mA
≤
I
O
≤
1A
LM2940, LM2940/883
LM2940C
100 mADC and
20 mArms,
f
O
= 120 Hz
Quiescent
Current
V
O
+2V
≤
V
IN
≤
26V,
I
O
= 5 mA
LM2940, LM2940/883
LM2940C
V
IN
= V
O
+ 5V, I
O
= 1A
Output Noise
Voltage
Ripple Rejection
10 Hz − 100 kHz,
I
O
= 5 mA
f
O
= 120 Hz, 1 V
rms
,
I
O
= 100 mA
LM2940
LM2940C
f
O
= 1 kHz, 1 V
rms
,
I
O
= 5 mA
66
66
54/48
54
52/46
64
55
55
80
120/200
120
120/190
70
1000/1000
100
12.00
20
11.64/11.40
12.36/12.60
120
11.64/11.40
12.36/12.60
75/120
20
15.00
16.75V
≤
V
IN
≤
26V
14.55/14.25
15.45/15.75
150
14.55/14.25
15.45/15.75
95/150
V
MIN
V
MAX
mV
MAX
150/240
150
1000/1000
mV
MAX
Output
Impedance
mΩ
10
10
30
360
15/20
15
45/60
15/20
10
50/60
1000/1000
30
450
15
45/60
15/20
50/60
1000/1000
mA
MAX
mA
MAX
µV
rms
dB
MIN
52
48/42
dB
MIN
http://www.hgsemi.com.cn
5
2015 MAR
单片机
京公网安备 11010802033920号
Copyright © 2005-2026 EEWORLD.com.cn, Inc. All rights reserved
电子工程世界
