MICROCIRCUIT DATA SHEET
MNLM2940-15-X REV 1A1
1A LOW DROPOUT REGULATOR
General Description
The LM2940 positive voltage regulator features the ability to source 1A of ouput 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 voltage 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 (Vin - Vout < 3V).
Designed also for vehicular applications, the LM2940 and all regulated circuitry are
protected from reverse battery installations or 2-battery jumps. During line transients,
such as load dump when the input voltage can momentarily exceed the specified maximum
operating voltage, the regulator will automatically shut down to protect both the internal
circuits and the load. The LM2940 cannot be harmed by temporary mirror-image insertion.
Familiar regulator features such as short circuit and thermal overload protection are also
provided.
Original Creation Date: 07/22/96
Last Update Date: 10/08/99
Last Major Revision Date: 07/22/96
Industry Part Number
LM2940
NS Part Numbers
LM2940J-15/883
LM2940K-15/883
LM2940WG-15/883
Prime Die
LM2940
Controlling Document
SEE FEATURE SECTION
Processing
MIL-STD-883, Method 5004
Subgrp Description
1
2
3
4
5
6
7
8A
8B
9
10
11
Static tests at
Static tests at
Static tests at
Dynamic tests at
Dynamic tests at
Dynamic tests at
Functional tests at
Functional tests at
Functional tests at
Switching tests at
Switching tests at
Switching tests at
Temp (
o
C)
+25
+125
-55
+25
+125
-55
+25
+125
-55
+25
+125
-55
Quality Conformance Inspection
MIL-STD-883, Method 5005
1
MNLM2940-15-X REV 1A1
MICROCIRCUIT DATA SHEET
Features
-
-
-
-
-
-
-
-
-
-
Dropout voltage typically 0.5V @ Io = 1A
Output current in excess of 1A
Output voltage trimmed before assembly
Reverse battery protection
Internal short circuit current limit
Mirror image insertion protection
CONTROLLING DOCUMENT
LM2940J-15/883
5962-9088501QEA
LM2940K-15/883
5962-9088501MYA
LM2940WG-15/883
5962-9088501QXA
2
MNLM2940-15-X REV 1A1
MICROCIRCUIT DATA SHEET
(Absolute Maximum Ratings)
(Note 1)
Input Voltage (Survival Voltage <100ms)
60V
Internal Power Dissipation
(Note 2, 3)
Internally Limited
Maximum Junction Temperature
150 C
Storage Temperature Range
-65 C to +150 C
Lead Temperature
(Soldering, 10 seconds)
Thermal Resistance
ThetaJA
T03 Pkg
(Still Air)
T03 Pkg
(500LF/Min Air Flow)
CERDIP
(Still Air)
CERDIP
(500LF/Min Air Flow)
CERAMIC SOIC (Still Air)
CERAMIC SOIC (500LF/Min Air Flow)
ThetaJC
T03 Pkg
CERDIP
(Note 3)
CERAMIC SOIC
(Note 3)
Package Weight
(Typcial)
T03 Pkg
CERDIP
CERAMIC SOIC
ESD Susceptibility
(Note 4)
300 C
40
TBD
73
37
122
77
C/W
C/W
C/W
C/W
C/W
5 C/W
3 C/W
5 C/W
TBD
1970mg
360mg
4000V
Note 1:
Absolute Maximum Ratings are limits beyond which damage to the device may occur.
Operating Ratings are conditions for which the device is functional, but do not
guaranteed specific performance limits. For guaranteed specifications and test
conditions see the Electrical Characteristics. The guaranteed specifications apply
only for the test conditions listed. Some performance characteristics may degrade
when the device is not operated under the listed test conditions.
The maximum power dissipation must be derated at elevated temperatures and is
dictated by Tjmax (maximum junction temperature), ThetaJA (package junction to
ambient thermal resistance), and TA (ambient temperature). The maximum allowable
power dissipation at any temperature is Pdmax = (Tjmax - TA)/ThetaJA or the number
given in the Absolute Maximum Ratings, whichever is lower.
The package material for these devices allows much improved heat transfer over our
standard ceramic packages. In order to take full advantage of this improved heat
transfer, heat sinking must be provided between the package base (directly beneath
the die), and either metal traces on, or thermal vias through, the printed circuit
board. Without this additional heat sinking, device power dissipation must be
calculated using junction-to-ambient, rather than junction-to-case, thermal
resistance. It must not be assumed that the device leads will provide substantial
heat transfer out of the package, since the thermal resistance of the leadframe
material is very poor, relative to the material of the package base. The stated
junction-to-case thermal resistance is for the package material only, and does not
account for the additional thermal resistance between the package base and the
printed circuit board. The user must determine the value of the additional thermal
resistance and must combine this with the stated value for the package, to calculate
the total allowed power dissipation for the device.
Human body model, 100pF discharged through 1.5K Ohms
Note 2:
Note 3:
Note 4:
3
MNLM2940-15-X REV 1A1
MICROCIRCUIT DATA SHEET
Recommended Operating Conditions
(Note 1)
Input Voltage
26V
Operating Temperature Range
-55 C < TA < +125 C
Note 1:
Absolute Maximum Ratings are limits beyond which damage to the device may occur.
Operating Ratings are conditions for which the device is functional, but do not
guaranteed specific performance limits. For guaranteed specifications and test
conditions see the Electrical Characteristics. The guaranteed specifications apply
only for the test conditions listed. Some performance characteristics may degrade
when the device is not operated under the listed test conditions.
4
MNLM2940-15-X REV 1A1
MICROCIRCUIT DATA SHEET
Electrical Characteristics
DC PARAMETERS:
(The following conditions apply to all the following parameters, unless otherwise specified.)
DC: Vin = 20V, Io = 1A, Cout = 22uF
SYMBOL
Vout
PARAMETER
Output Voltage
CONDITIONS
Vin = 20V, Io = 5mA
NOTES
PIN-
NAME
MIN
14.55
14.25
Vin = 16.75V, Io = 5mA
14.55
14.25
Vin = 17V, Io = 5mA
14.55
14.25
Vin = 26V, Io = 5mA
14.55
14.25
Vin = 20V, Io = 1A
14.55
14.25
Vin = 16.75V, Io = 1A
14.55
14.25
Vin = 16.75V, Io = 50mA
14.55
14.25
Vin = 20V, Io = 50mA
14.55
14.25
Reverse Polarity
Input Voltage DC
Iq
Quiescent Current
Ro = 100 Ohms
Vin = 20V, Io = 5mA
1
-15
0
0
Vin = 17V, Io = 5mA
0
0
Vin = 26V, Io = 5mA
0
0
Vin = 20V, Io = 1A
0
0
Vrline
Line Regulation
17V < Vin < 26V, Io = 5mA
-95
-150
Vrload
Load Regulation
Vin = 20V, 50mA < Io < 1A
-150
-240
15
20
15
20
15
20
50
60
95
150
150
240
MAX
15.45
15.75
15.45
15.75
15.45
15.75
15.45
15.75
15.45
15.75
15.45
15.75
15.45
15.75
15.45
15.75
UNIT
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
V
mA
mA
mA
mA
mA
mA
mA
mA
mV
mV
mV
mV
SUB-
GROUPS
1
2, 3
1
2, 3
1
2, 3
1
2, 3
1
2, 3
1
2, 3
1
2, 3
1
2, 3
1, 2,
3
1
2, 3
1
2, 3
1
2, 3
1
2, 3
1
2, 3
1
2, 3
5
