LM2940 - 1A Low Dropout Regulator

LM2940 - 1A Low Dropout Regulator

Datasheet	Packaging	Samples & Pricing	Reliability	Application Notes	Knowledge Base

Features

•	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

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. More...

Typical Application

click for larger image

Parameters Values

Output Current 1000 mA

Output Min 9, 12, 15, 8, 10, 5 Volt

Input Min Voltage Undefined Volt

Input Max Voltage 26 Volt

Dropout Voltage 0.5 Volt

Adjustable Output No

Quiescent Current 10 mA

On/Off Pin No

Error Flag No

RegType LDO

Temperature Min -40, -55 deg C

Temperature Max 125, 85 deg C

Output Max 9, 12, 15, 8, 10, 5 Volt

Output Voltage 9, 12, 15, 8, 10, 5 Volt

Typical Performance

click for larger image

Also Recommended

LP38690▲	Lower Quiescent Current, Stable With Ceramic Output Capacitors
LP38692▲	Lower Quiescent Current, Stable With Ceramic Output Capacitors & Enable Pin

Additional Resources

Application Notes

Connection Diagram

click for larger image

Datasheet

RoHS Compliance Information	Size in Kbytes	Date
LM2940/LM2940C 1A Low Dropout Regulator	565 Kbytes	18-Mar-07	Download
LM2940/LM2940C 1A Low Dropout Regulator (Japanese)	740 Kbytes
LM2940 Mil-Aero Datasheet MNLM2940-12-X	261 Kbytes		Download
LM2940 Mil-Aero Datasheet MNLM2940-15-X	261 Kbytes		Download
LM2940 Mil-Aero Datasheet MNLM2940-5.0-X	262 Kbytes		Download

If you have trouble printing or viewing PDF file(s), see Printing Problems.

Package Availability, Models, Samples & Pricing

Part Number

Package

Factory Lead Time

Models

Samples &
Electronic
Orders

Budgetary Pricing

Std
Pack
Size

Package
Marking
Format

Type

Pins

Spec.

MSL
Rating

Peak
Reflow

RoHS
Report

CAD
Symbols

Qty

Qty

$US each

LM2940LD-12

8

NOPB

3

260

Full production

N/A

Buy Now

1K+

$0.95

reel
of
1000

NS
UZXYTT
L00018B

8 weeks

2000

LM2940LD-5.0

8

NOPB

3

260

Full production

N/A

Buy Now

1K+

$0.95

reel
of
1000

NS
UZXYTT
L00014B

8 weeks

2000

LM2940LDX-5.0

8

NOPB

3

260

Lifetime buy

N/A

Buy Now

1K+

$0.95

reel
of
4500

NS
UZXYTT
L00014B

8 weeks

N/A

LM2940IMP-8.0

4

NOPB
STD

1
1

260
260

Lifetime buy

N/A

Buy Now

1K+

$0.81

reel
of
1000

8 weeks

2000

LM2940IMP-10

4

NOPB

1

260

Full production

N/A

Buy Now

1K+

$0.81

reel
of
1000

8 weeks

2500

LM2940IMP-12

4

NOPB
STD

1
1

260
260

Full production

N/A

Samples

Buy Now

1K+

$0.81

reel
of
1000

8 weeks

2000

LM2940IMP-15

4

NOPB
STD

1
1

260
260

Full production

N/A

Buy Now

1K+

$0.81

reel
of
1000

8 weeks

2000

LM2940IMP-5.0

4

NOPB
STD

1
1

260
260

Full production

N/A

Samples

Buy Now

1K+

$0.81

reel
of
1000

6 weeks

2000

LM2940IMP-9.0

4

NOPB

1

260

Full production

N/A

Buy Now

1K+

$0.81

reel
of
1000

8 weeks

3000

LM2940IMPX-15

4

NOPB

1

260

Lifetime buy

N/A

Buy Now

1K+

$0.81

reel
of
2000

8 weeks

5000

LM2940IMPX-10

4

NOPB

1

260

Full production

N/A

Buy Now

1K+

$0.81

reel
of
2000

8 weeks

2500

LM2940IMPX-12

4

NOPB

1

260

Full production

N/A

Buy Now

1K+

$0.81

reel
of
2000

8 weeks

10000

LM2940IMPX-5.0

4

NOPB
STD

1
1

260
260

Full production

N/A

Buy Now

1K+

$0.81

reel
of
2000

8 weeks

2500

LM2940IMPX-8.0

4

NOPB

1

260

Full production

N/A

Buy Now

1K+

$0.81

reel
of
2000

8 weeks

3000

LM2940T-10.0

3

NOPB
STD

1
1

NA
NA

Full production

N/A

Samples

Buy Now

1K+

$0.67

rail
of
45

NSUZXYTTE#
LM2940T
10.0 P+

8 weeks

1000

LM2940T-12.0

3

NOPB
STD

1
1

NA
NA

Full production

N/A

Samples

Buy Now

1K+

$0.67

rail
of
45

NSUZXYTTE#
LM2940T
12.0 P+

8 weeks

1000

LM2940T-5.0

3

NOPB
STD

1
1

NA
NA

Full production

N/A

Samples

Buy Now

1K+

$0.67

rail
of
45

NSUZXYTTE#
LM2940T
-5.0 P+

12 weeks

5000

LM2940T-8.0

3

NOPB
STD

1
1

NA
NA

Full production

N/A

Samples

Buy Now

1K+

$0.67

rail
of
45

NSUZXYTTE#
LM2940T
-8.0 P+

8 weeks

1000

LM2940T-9.0

3

NOPB
STD

1
1

NA
NA

Full production

N/A

Samples

Buy Now

1K+

$0.67

rail
of
45

NSUZXYTTE#
LM2940T
-9.0 P+

8 weeks

2500

LM2940S-10

3

NOPB
STD

3
3

245
235

Full production

N/A

Samples

Buy Now

1K+

$0.81

rail
of
45

NSUZXYTTE#
LM2940S
-10 P+

8 weeks

1000

LM2940S-12

3

NOPB
STD

3
3

245
235

Full production

N/A

Samples

Buy Now

1K+

$0.81

rail
of
45

NSUZXYTTE#
LM2940S
-12 P+

8 weeks

1000

LM2940S-5.0

3

NOPB
STD

3
3

245
235

Full production

N/A

Samples

Buy Now

1K+

$0.81

rail
of
45

NSUZXYTTE#
LM2940S
-5.0 P+

8 weeks

2000

LM2940S-8.0

3

NOPB
STD

3
3

245
235

Full production

N/A

Samples

Buy Now

1K+

$0.85

rail
of
45

NSUZXYTTE#
LM2940S
-8.0 P+

8 weeks

1000

LM2940S-9.0

3

NOPB

3

245

Full production

N/A

Buy Now

1K+

$0.85

rail
of
45

NSUZXYTTE#
LM2940S
-9.0 P+

8 weeks

2000

LM2940SX-10

3

NOPB
STD

3
3

245
235

Full production

N/A

Buy Now

1K+

$0.81

reel
of
500

NSUZXYTTE#
LM2940S
-10 P+

8 weeks

2000

LM2940SX-12

3

NOPB
STD

3
3

245
235

Full production

N/A

Buy Now

1K+

$0.81

reel
of
500

NSUZXYTTE#
LM2940S
-12 P+

8 weeks

3000

LM2940SX-5.0

3

NOPB
STD

3
3

245
235

Full production

N/A

Buy Now

1K+

$0.81

reel
of
500

NSUZXYTTE#
LM2940S
-5.0 P+

8 weeks

2500

LM2940SX-8.0

3

NOPB
STD

3
3

245
235

Full production

N/A

Buy Now

1K+

$0.85

reel
of
500

NSUZXYTTE#
LM2940S
-8.0 P+

8 weeks

2000

LM2940SX-9.0

3

NOPB

3

245

Full production

N/A

Buy Now

1K+

$0.85

reel
of
500

NSUZXYTTE#
LM2940S
-9.0 P+

8 weeks

2000

LM2940WG5.0/883

16

STD

1

NA

Full production

N/A

50+

$76.90

tray
of
42

NSZSSXXYYA
LM2940WG5.0/
883 Q 5962-
8958701XA

10 weeks

100

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM2940C-5 MWC	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM2940IMP-8.0	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM2940IMPX-15	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM2940IMPX-9.0	LT1086	SEMTECH	16 Nov 2008
LM2940J-12/883	NONE	NATIONAL SEMICONDUCTOR	03 Dec 2008
LM2940J-15/883	NONE	NATIONAL SEMICONDUCTOR	03 Dec 2008
LM2940J-5.0/883	NONE	NATIONAL SEMICONDUCTOR	03 Dec 2008
LM2940K-12/883	NONE	NONE	08 Sep 1999
LM2940K-15-MIL	NONE	NONE	08 Sep 1999
LM2940K-15/883	NONE	NONE	07 Dec 1999
LM2940K-5.0/883	NONE	NONE	08 Sep 1999
LM2940K-8.0/883	NONE	NONE	08 Sep 1999
LM2940LD-10	LT1086	SEMTECH	16 Nov 2008
LM2940LD-15	EC1086	ECI	16 Nov 2008
LM2940LD-8.0	EC1086	ECI	16 Nov 2008
LM2940LD-9.0	LT1086	SEMTECH	16 Nov 2008
LM2940LDX-10	EC1086	ECI	16 Nov 2008
LM2940LDX-12	LT1086	SEMTECH	16 Nov 2008
LM2940LDX-15	EC1086	ECI	16 Nov 2008
LM2940LDX-5.0	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM2940LDX-8.0	LT1086	SEMTECH	16 Nov 2008
LM2940LDX-9.0	EC1086	ECI	16 Nov 2008
LM2940WG-12/883	NONE	NATIONAL SEMICONDUCTOR	03 Dec 2008
LM2940WG-15/883	NONE	NATIONAL SEMICONDUCTOR	03 Dec 2008

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 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 − V_OUT ≤ 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.

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM2940IMP-10	SLM	0	44046	0	0	3532500	1	1002356520
LM2940IMP-12	SLM	0	44046	0	0	3532500	1	1002356520
LM2940IMP-15	SLM	0	44046	0	0	3532500	1	1002356520
LM2940IMP-5.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940IMP-8.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940IMP-9.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940IMPX-10	SLM	0	44046	0	0	3532500	1	1002356520
LM2940IMPX-12	SLM	0	44046	0	0	3532500	1	1002356520
LM2940IMPX-15	SLM	0	44046	0	0	3532500	1	1002356520
LM2940IMPX-5.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940IMPX-8.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940IMPX-9.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940LD-12	SLM	0	44046	0	0	3532500	1	1002356520
LM2940LD-15	SLM	0	44046	0	0	3532500	1	1002356520
LM2940LD-5.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940LD-8.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940LD-9.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940LDX-5.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940S-10	SLM	0	44046	0	0	3532500	1	1002356520
LM2940S-12	SLM	0	44046	0	0	3532500	1	1002356520
LM2940S-5.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940S-8.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940S-9.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940SX-10	SLM	0	44046	0	0	3532500	1	1002356520
LM2940SX-12	SLM	0	44046	0	0	3532500	1	1002356520
LM2940SX-5.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940SX-8.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940SX-9.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940T-10.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940T-12.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940T-5.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940T-8.0	SLM	0	44046	0	0	3532500	1	1002356520
LM2940T-9.0	SLM	0	44046	0	0	3532500	1	1002356520

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

For more information on Reliability Metrics, please click here.

More Application Notes

Title	Size in Kbytes	Date
AN-1378: Application Note 1378 Method For Calculating Output Voltage Tolerances in Adjustable Regulators	647 Kbytes	15-Jul-05	Download
AN-1378 (Chinese): Application Note 1378 Method For Calculating Output Voltage Tolerances in Adjustable Regulators	383 Kbytes

If you have trouble printing or viewing PDF file(s), see Printing Problems.

[Information as of 7-Nov-2009]