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LM3940  Product Folder

IA Low Dropout Regulator for 5V to 3.3V Conversion
Generic P/N 3940
General
Description		 Features Datasheet Package
& Models		 Samples
& Pricing		 Reliability
Metrics		 Application
Notes

Parametric Table Parametric Table
Temperature Min (deg C) -40 
Temperature Max (deg C) 125 
Multiple Output Capability No 
On/Off Pin No 
Error Flag No 
InputMin Voltage (Volt) - 
InputMax Voltage (Volt) 7.50 
Output Current (mA) 1000 
Dropout Voltage (Volt) .50 
Quiescent Current (mA) 10 
SecondaryOutput Voltage (Volt) - 
SecondaryOutput Current (Amp) - 
RegType LDO 
Output Voltage (Volt) 3.30 
Watchdog No 

Datasheet

TitleSize in KbytesDate
View Online
Download
Receive via Email
LM3940 1A Low Dropout Regulator for 5V to 3.3V Conversion 369 Kbytes 27-Jan-03 View Online Download Receive via Email
LM3940 1A Low Dropout Regulator for 5V to 3.3V Conversion (JAPANESE)
 368 Kbytes   View Online Download Receive via Email
LM3940 Mil-Aero Datasheet MNLM3940-3.3-X 121 Kbytes   View Online Download Receive via Email

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

Package Availability, Models, Samples & Pricing

Part NumberPackageStatusModelsSamples &
Electronic
Orders		Budgetary PricingStd
Pack
Size		Package
Marking
TypePinsMSL/Lead-Free AvailabilityLead
Time		QtySPICEIBISQty$US each
LM3940LD-3.3LLP8StatusFull productionN/AN/ASamples
Buy Now		1K+$0.75reel
of
1000		NS
UZXYTT
L00013B
11-13 weeks30000
LM3940LDX-3.3LLP8StatusFull productionN/AN/A 1K+$0.75reel
of
4500		NS
UZXYTT
L00013B
11-13 weeks30000
LM3940IMP-3.3SOT-2234StatusFull productionN/AN/ASamples
Buy Now 		1K+$0.75reel
of
1000		XYTT
L52B
17 weeks0
LM3940IMPX-3.3SOT-2234StatusFull productionN/AN/A 
Buy Now 		1K+$0.75reel
of
2000		XYTT
L52B
16 weeks0
LM3940IT-3.3TO 2203StatusFull productionN/AN/A24 Hour Samples
Buy Now 		1K+$0.85rail
of
45		NSUZXYTT
LM3940IT
-3.3 P+
4-6 weeks30000
LM3940IS-3.3TO 2633StatusFull productionN/AN/A24 Hour Samples
Buy Now 		1K+$0.85rail
of
45		NSUZXYTT
LM3940IS
-3.3 P+
13 weeks0
LM3940ISX-3.3TO 2633StatusFull productionN/AN/A 
Buy Now 		1K+$0.85reel
of
500		NSUZXYTT
LM3940IS
-3.3 P+
14 weeks0
LM3940J-3.3-SCDCERDIP16StatusLifetime buyN/AN/A   rail
of
N/A		NSZSSXXYYA>
LM3940J-3.3-SCD
12 weeks0
5962-9688401QEACERDIP16StatusLifetime buyN/AN/A 250+$11.70rail
of
25		NSZSSXXYYA>
LM3940J-3.3-QML
5962-9688401QEA
N/A0
LM3940WG3.3-SCDCERPACK16StatusLifetime buyN/AN/A   tray
of
N/A		NSZSSXXYYA>
LM3940WG3.3
-SCD
12 weeks0
LM3940WG3.3-QMLCERPACK16StatusLifetime buyN/AN/A 250+$14.90tray
of
42		NSZSSXXYYA>
LM3940WG3.3
-QML
9688401QXA
N/A0
LM3940I-3.3 MDCUnpackaged DieFull productionN/AN/ASamples  tray
of
N/A		-
N/A0
LM3940I-3.3 MWCWaferFull productionN/AN/A   wafer jar
of
N/A		-
N/A0

Obsolete Parts

Obsolete PartAlternate Part or SupplierSourceLast Time Buy Date
LM3940J-3.3-MPR
NATIONAL
NONE
12/01/2004
LM3940J-3.3-QML
LM3940J-3.3-SCD
NATIONAL SEMICONDUCTOR
06/02/2004
LM3940J-3.3-SCD
NATIONAL
NONE
12/01/2004
LM3940WG3.3-MPR
NATIONAL
NONE
12/01/2004
LM3940WG3.3-QML
LM3940WG3.3-SCD
NATIONAL SEMICONDUCTOR
06/02/2004
LM3940WG3.3-SCD
NATIONAL
NONE
12/01/2004

General Description

The LM3940 is a 1A low dropout regulator designed to provide 3.3V from a 5V supply.

The LM3940 is ideally suited for systems which contain both 5V and 3.3V logic, with prime power provided from a 5V bus.

Because the LM3940 is a true low dropout regulator, it can hold its 3.3V output in regulation with input voltages as low as 4.5V.

The T0-220 package of the LM3940 means that in most applications the full 1A of load current can be delivered without using an additional heatsink.

The surface mount TO-263 package uses minimum board space, and gives excellent power dissipation capability when soldered to a copper plane on the PC board.

Features

  • Output voltage specified over temperature
  • Excellent load regulation
  • Guaranteed 1A output current
  • Requires only one external component
  • Built-in protection against excess temperature
  • Short circuit protected

Applications

  • Laptop/Desktop Computers
  • Logic Systems

Reliability Metrics

Part Number Process Early Failure Rate - Rejects Sample Size (EFR) PPM * Rel. Rejects Device Hours Long Term Failure Rates (FITS) MTTF
LM3940I-3.3 MDCSLM0350000015000003424108012
LM3940I-3.3 MWCSLM0350000015000003424108012
LM3940IMP-3.3SLM0350000015000003424108012
LM3940IMPX-3.3SLM0350000015000003424108012
LM3940IS-3.3SLM0350000015000003424108012
LM3940ISX-3.3SLM0350000015000003424108012
LM3940IT-3.3SLM0350000015000003424108012
LM3940LD-3.3SLM0350000015000003424108012
LM3940LDX-3.3SLM0350000015000003424108012

For more information on Reliablitity Metrics, please click here.


Application Notes

TitleSize in KbytesDate
View Online
Download
Receive via Email
AN-1061: Application Note 1061 Power Conversion in Line-Powered Equipment 188 Kbytes 1-Oct-02 View Online Download Receive via Email
AN-1148: Application Note 1148 Linear Regulators: Theory of Operation and Compensation 200 Kbytes 25-Sep-02 View Online Download Receive via Email

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

[Information as of 15-Jan-2004]

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