NSC LM2940CT-9.0, LM2940CT-5MWC, LM2940CT-5.0, LM2940CT-15MWC, LM2940CT-15MDC Datasheet

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 beenincluded 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
(V

IN−VOUT

≤ 3V).

Designed also for vehicular applications, the LM2940/
LM2940C 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/
LM2940C cannot be harmed by temporary mirror-image in­sertion. Familiar regulator features such as short circuit and
thermal overload protection are also provided.

Features

n Dropout voltage typically 0.5V@IO=1A
n Output current in excess of 1A
n Output voltage trimmed before assembly
n Reverse battery protection
n Internal short circuit current limit
n Mirror image insertion protection
n P

+

Product Enhancement tested

Typical Application

Ordering Information

Temperature

Range

Output Voltage

Package

5.0 8.0 9.0 10 12 15

0˚C ≤ T

J

≤ 125˚C LM2940CT-5.0 LM2940CT-9.0 LM2940CT-12 LM2940CT-15 TO-220

LM2940CS-5.0 LM2940CS-9.0 LM2940CS-12 LM2940CS-15 TO-263

−40˚C ≤ T

J

≤ 125˚C LM2940T-5.0 LM2940T-8.0 LM2940T-9.0 LM2940T-10 LM2940T-12 TO-220

LM2940S-5.0 LM2940S-8.0 LM2940S-9.0 LM2940S-10 LM2940S-12 TO-263

−40˚C ≤ T

J

≤ 85˚C LM2940IMP-5.0 LM2940IMP-8.0 LM2940IMP-9.0 LM2940IMP-10 LM2940IMP-12 LM2940IMP-15 SOT-223

LM2940IMPX-5.0 LM2940IMPX-8.0 LM2940IMPX-9.0 LM2940IMPX-10 LM2940IMPX-12 LM2940IMPX-15 SOT-223

in Tape
and Reel

SOT-223 Package

Marking

L53B L54B L0EB L55B L56B L70B

The physical size of the SOT-223 is too small to contain the full device part number. The package markings indicated are what will appear on the actual device.

Temperature

Range

Output Voltage Package

5.0 8.0 12 15

−55˚C ≤ T

J

≤ 125˚C LM2940J-5.0/883

5962-8958701EA

LM2940J-8.0/883

5962-9088301QEA

LM2940J-12/883

5962-9088401QEA

LM2940J-15/883

5962-9088501QEA

J16A

LM2940WG5.0/883

5962-8958701XA

WG16A

For information on military temperature range products, please go to the Mil/Aero Web Site at http://www.national.com/appinfo/milaero/index.html.

DS008822-3

*

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.

March 2000

LM2940/LM2940C 1A Low Dropout Regulator

© 2000 National Semiconductor Corporation DS008822 www.national.com

Connection Diagrams

(TO-220) Plastic Package

DS008822-2

Front View

Order Number LM2940CT-5.0, LM2940CT-9.0,

LM2940CT-12, LM2940CT-15, LM2940T-5.0,

LM2940T-8.0, LM2940T-9.0,

LM2940T-10 or LM2940T-12

See NS Package Number TO3B

3-Lead SOT-223

DS008822-42

Front View

Order Part Number LM2940IMP-5.0,

LM2940IMP-8.0, LM2940IMP-9.0,

LM2940IMP-10, LM2940IMP-12 or LM2940IMP-15

See NS Package Number MP04A

16-Lead Dual-in-Line Package (J)

DS008822-43

Top View

Order Number LM2940J-5.0/883 (5962-8958701EA),

LM2940J-8.0/883 (5962-9088301QEA),

LM2940J-12/883 (5962-9088401QEA),

LM2940J-15/883 (5962-9088501QEA)

See NS Package Number J16A

16-Lead Ceramic Surface-Mount Package (WG)

DS008822-44

Top View

Order Number LM2940WG5.0/883 (5962-8958701XA)

See NS Package Number WG16A

(TO-263) Surface-Mount Package

DS008822-11

Top View

DS008822-12

Side View

Order Number LM2940CS-5.0, LM2940CS-9.0,

LM2940CS-12, LM2940CS-15,

LM2940S-5.0, LM2940S-8.0,

LM2940S-9.0, LM2940S-10 or LM2940S-12

See NS Package Number TS3B

LM2940/LM2940C

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Absolute Maximum Ratings (Note 1)

If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.

LM2940S, T, MP ≤ 100 ms 60V
LM2940CS, T ≤ 1 ms 45V
Internal Power Dissipation

(Note 2) Internally Limited
Maximum Junction Temperature 150˚C
Storage Temperature Range −65˚C ≤ T

J

≤ +150˚C

Lead Temperature, Time for Wave Soldering

TO-220 (T) Package 260˚C, 10s

TO-263 (S) Package 260˚C, 4s
SOT-223 (MP) Package 260˚C, 4s

ESD Susceptibility (Note 3) 2 kV

Operating Conditions (Note 1)

Input Voltage 26V
Temperature Range

LM2940T, LM2940S −40˚C ≤ T

J

≤ 125˚C

LM2940CT, LM2940CS 0˚C ≤ T

J

≤ 125˚C

LM2940IMP −40˚C ≤ T

J

≤ 85˚C

LM2940J, LM2940WG −55˚C ≤ T

J

≤ 125˚C

Electrical Characteristics

VIN=VO+ 5V, IO= 1A, CO= 22 µF, unless otherwise specified. Boldface limits apply over the entire operating tempera­ture range of the indicated device. All other specifications apply for T

A=TJ

= 25˚C.

Output Voltage (V

O

)5V 8V

Units

LM2940 LM2940/883 LM2940 LM2940/883

Parameter Conditions Typ Limit Limit Typ Limit Limit

(Note 4) (Note 5) (Note 4) (Note 5)

6.25V ≤ V

IN

≤ 26V 9.4V ≤ VIN≤ 26V

Output Voltage 5 mA ≤ I

O

≤ 1A 5.00 4.85/4.75 4.85/4.75 8.00 7.76/7.60 7.76/7.60 V

MIN

5.15/5.25 5.15/5.25 8.24/8.40 8.24/8.40 V

MAX

Line Regulation VO+2V≤VIN≤ 26V, 20 50 40/50 20 80 50/80 mV

MAX

IO=5mA

Load Regulation 50 mA ≤ I

O

≤ 1A

LM2940, LM2940/883 35 50/80 50/100 55 80/130 80/130 mV

MAX

LM2940C 35 50 55 80
Output 100 mADC and
Impedance 20 mArms, 35 1000/1000 55 1000/1000 mΩ

f

O

= 120 Hz

Quiescent V

O

+2V ≤ VIN≤ 26V,

Current I

O

=5mA

LM2940, LM2940/883 10 15/20 15/20 10 15/20 15/20 mA

MAX

LM2940C 10 15

V

IN=VO

+ 5V, 30 45/60 50/60 30 45/60 50/60 mA

MAX

IO=1A
Output Noise 10 Hz − 100 kHz, 150 700/700 240 1000/1000 µV

rms

Voltage IO=5mA
Ripple Rejection f

O

= 120 Hz, 1 V

rms

,

I

O

= 100 mA

LM2940 72 60/54 66 54/48 dB

MIN

LM2940C 72 60 66 54

f

O

= 1 kHz, 1 V

rms

, 60/50 54/48 dB

MIN

IO=5mA
Long Term 20 32 mV/
Stability 1000 Hr
Dropout Voltage I

O

= 1A 0.5 0.8/1.0 0.7/1.0 0.5 0.8/1.0 0.7/1.0 V

MAX

IO= 100 mA 110 150/200 150/200 110 150/200 150/200 mV

MAX

Short Circuit
Current

(Note 6)

1.9 1.6 1.5/1.3 1.9 1.6 1.6/1.3 A

MIN

LM2940/LM2940C

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Electrical Characteristics (Continued)

VIN=VO+ 5V, IO= 1A, CO= 22 µF, unless otherwise specified. Boldface limits apply over the entire operating tempera­ture range of the indicated device. All other specifications apply for TA=TJ= 25˚C.

Output Voltage (V

O

)5V 8V

Units

LM2940 LM2940/883 LM2940 LM2940/883

Parameter Conditions Typ Limit Limit Typ Limit Limit

(Note 4) (Note 5) (Note 4) (Note 5)

Maximum Line R

O

= 100Ω

V

MIN

Transient LM2940, T ≤ 100 ms 75 60/60 75 60/60

LM2940/883, T ≤ 20 ms 40/40 40/40
LM2940C, T ≤ 1ms5545 5545

Reverse Polarity R

O

= 100Ω

DC Input Voltage LM2940, LM2940/883 −30 −15/−15 −15/−15 −30 −15/−15 −15/−15 V

MIN

LM2940C −30 −15 −30 −15

Reverse Polarity R

O

= 100Ω

Transient Input LM2940, T ≤ 100 ms −75 −50/−50 −75 −50/−50 V

MIN

Voltage LM2940/883, T ≤ 20 ms −45/−45 −45/−45

LM2940C, T ≤ 1 ms −55 −45/−45

Electrical Characteristics

VIN=VO+ 5V, IO= 1A, CO= 22 µF, unless otherwise specified. Boldface limits apply over the entire operating tempera­ture range of the indicated device. All other specifications apply for TA=TJ= 25˚C.

Output Voltage (V

O

) 9V 10V

Units

Parameter Conditions Typ

LM2940

Typ

LM2940

Limit Limit

(Note 4) (Note 4)

10.5V ≤ V

IN

≤ 26V 11.5V ≤ VIN≤ 26V

Output Voltage 5 mA ≤ I

O

≤1A 9.00 8.73/8.55 10.00 9.70/9.50 V

MIN

9.27/9.45 10.30/10.50 V

MAX

Line Regulation VO+2V≤VIN≤ 26V, 20 90 20 100 mV

MAX

IO=5mA

Load Regulation 50 mA ≤ I

O

≤ 1A

LM2940 60 90/150 65 100/165 mV

MAX

LM2940C 60 90

Output Impedance 100 mADC and

20 mArms, 60 65 mΩ
f

O

= 120 Hz

Quiescent V

O

+2V ≤ V

IN

<

26V,

Current I

O

=5mA

LM2940 10 15/20 10 15/20 mA

MAX

LM2940C 10 15
V

IN=VO

+ 5V, IO= 1A 30 45/60 30 45/60 mA

MAX

Output Noise 10 Hz − 100 kHz, 270 300 µV

rms

Voltage IO=5mA
Ripple Rejection f

O

= 120 Hz, 1 V

rms

,

I

O

= 100 mA

LM2940 64 52/46 63 51/45 dB

MIN

LM2940C 64 52

Long Term
Stability

34 36 mV/

1000 Hr

Dropout Voltage I

O

= 1A 0.5 0.8/1.0 0.5 0.8/1.0 V

MAX

IO= 100 mA 110 150/200 110 150/200 mV

MAX

LM2940/LM2940C

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Electrical Characteristics (Continued)

VIN=VO+ 5V, IO= 1A, CO= 22 µF, unless otherwise specified. Boldface limits apply over the entire operating tempera­ture range of the indicated device. All other specifications apply for TA=TJ= 25˚C.

Output Voltage (V

O

) 9V 10V

Units

Parameter Conditions Typ

LM2940

Typ

LM2940

Limit Limit

(Note 4) (Note 4)

Short Circuit (Note 6) 1.9 1.6 1.9 1.6 A

MIN

Current
Maximum Line R

O

= 100Ω

Transient T ≤ 100 ms

LM2940 75 60/60 75 60/60 V

MIN

LM2940C 55 45

Reverse Polarity R

O

= 100Ω

DC Input Voltage LM2940 −30 −15/−15 −30 −15/−15 V

MIN

LM2940C −30 −15

Reverse Polarity R

O

= 100Ω
Transient Input T ≤ 100 ms
Voltage LM2940 −75 −50/−50 −75 −50/−50 V

MIN

LM2940C −55 −45/−45

Electrical Characteristics

VIN=VO+ 5V, IO= 1A, CO= 22 µF, unless otherwise specified. Boldface limits apply over the entire operating tempera­ture range of the indicated device. All other specifications apply for T

A=TJ

= 25˚C.

Output Voltage (V

O

) 12V 15V

Units

LM2940 LM2940/833 LM2940 LM2940/833

Parameter Conditions Typ Limit Limit Typ Limit Limit

(Note 4) (Note 5) (Note 4) (Note 5)

13.6V ≤ V

IN

≤ 26V 16.75V ≤ VIN≤ 26V

Output Voltage 5 mA ≤ I

O

≤1A 12.00 11.64/11.40 11.64/11.40 15.00 14.55/14.25 14.55/14.25 V

MIN

12.36/12.60 12.36/12.60 15.45/15.75 15.45/15.75 V

MAX

Line Regulation VO+2V≤VIN≤ 26V, 20 120 75/120 20 150 95/150 mV

MAX

IO=5mA

Load Regulation 50 mA ≤ I

O

≤ 1A

LM2940, LM2940/883 55 120/200 120/190 150/240 mV

MAX

LM2940C 55 120 70 150
Output 100 mADC and
Impedance 20 mArms, 80 1000/1000 100 1000/1000 mΩ

f

O

= 120 Hz

Quiescent
Current

V

O

+2V ≤ VIN≤ 26V,

I

O

=5mA

LM2940, LM2940/883 10 15/20 15/20 15/20 mA

MAX

LM2940C 10 15 10 15

V

IN=VO

+ 5V, IO= 1A 30 45/60 50/60 30 45/60 50/60 mA

MAX

Output Noise 10 Hz − 100 kHz, 360 1000/1000 450 1000/1000 µV

rms

Voltage IO=5mA
Ripple Rejection f

O

= 120 Hz, 1 V

rms

,

I

O

= 100 mA

LM2940 66 54/48 dB

MIN

LM2940C 66 54 64 52

f

O

= 1 kHz, 1 V

rms

,

52/46 48/42

dB

MIN

IO=5mA

LM2940/LM2940C

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Electrical Characteristics (Continued)

VIN=VO+ 5V, IO= 1A, CO= 22 µF, unless otherwise specified. Boldface limits apply over the entire operating tempera­ture range of the indicated device. All other specifications apply for TA=TJ= 25˚C.

Output Voltage (V

O

) 12V 15V

Units

LM2940 LM2940/833 LM2940 LM2940/833

Parameter Conditions Typ Limit Limit Typ Limit Limit

(Note 4) (Note 5) (Note 4) (Note 5)

Long Term

48 60

mV/
Stability 1000 Hr
Dropout Voltage I

O

= 1A 0.5 0.8/1.0 0.7/1.0 0.5 0.8/1.0 0.7/1.0 V

MAX

IO= 100 mA 110 150/200 150/200 110 150/200 150/200 mV

MAX

Short Circuit (Note 6)

1.9 1.6 1.6/1.3 1.9 1.6 1.6/1.3 A

MIN

Current
Maximum Line R

O

= 100Ω

Transient LM2940, T ≤ 100 ms 75 60/60

LM2940/883, T ≤ 20 ms 40/40 40/40 V

MIN

LM2940C, T ≤ 1ms5545 5545

Reverse Polarity R

O

= 100Ω

DC Input LM2940, LM2940/883 −30 −15/−15 −15/−15 −15/−15 V

MIN

Voltage LM2940C −30 −15 −30 −15
Reverse Polarity R

O

= 100Ω
Transient Input LM2940, T ≤ 100 ms −75 −50/−50
Voltage LM2940/883, T ≤ 20 ms −45/−45 −45/−45 V

MIN

LM2940C, T ≤ 1 ms −55 −45/−45 −55 −45/−45

Note 1: Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Conditions are conditions under which the device functions
but the specifications might not be guaranteed. For guaranteed specifications and test conditions see the Electrical Characteristics.

Note 2: The maximum allowable power dissipation is a function of the maximum junction temperature, T

J

, the junction-to-ambient thermal resistance, θ

J−A

, and the

ambient temperature, T

A

. Exceeding the maximum allowable power dissipation will cause excessive die temperature, and the regulator will go into thermal shutdown.

The value ofθ

J−A

(for devices instillairwithnoheatsink) is 60˚C/W for the TO-220 package, 80˚C/W for the TO-263 package, and 174˚C/W for the SOT-223package.

The effective value of θ

J−A

can be reduced by using a heatsink (seeApplication Hints for specific information on heatsinking). The values of θ

J−A

and θ

J−C

for the K02A

package are 39˚C/W and 4˚C/W respectively.

Note 3: ESD rating is based on the human body model, 100 pF discharged through 1.5 kΩ.
Note 4: All limits are guaranteed at T

A=TJ

= 25˚C only (standard typeface) or over the entire operating temperature range of the indicated device (boldface type).

All limits at T

A=TJ

= 25˚C are 100% production tested. All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality Control

methods.
Note 5: All limits are guaranteed at T

A=TJ

= 25˚C only (standard typeface) or over the entire operating temperature range of the indicated device (boldface type).

All limits are 100% production tested and are used to calculate Outgoing Quality Levels.

Note 6: Output current will decrease with increasing temperature but will not drop below 1A at the maximum specified temperature.

Typical Performance Characteristics

Dropout Voltage

DS008822-13

Dropout Voltage
vs Temperature

DS008822-14

Output Voltage
vs Temperature

DS008822-15

LM2940/LM2940C

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