SPX3940

1.0A Low Dropout Voltage Regulator
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Overview

Information 1.0A Low Dropout Voltage Regulator
Output Option Fixed
VOUT (V) 2.5, 3.3, 5.0
VOUT Adj MIN (V) -
VOUT Adj MAX (V) -
IOUT (mA) 1000
VIN MIN (V) 3.1
VIN MAX (V) 16
IQ (µA) 18000
Accuracy (%) 2%
Vdrop (mV) 280
Output Noise (µVRMS) 260
PSRR (dB) -
Junction Temp Range (°C) -40 to 125
Package SOT223-3, TO263-3
Features Reverse battery protection, Current limit and thermal protection
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The SPX3940 is a 1A, accurate voltage regulator with a low drop out voltage of 280mV (typical) at 1A.

These regulators are specifically designed for low voltage applications that require a low dropout voltage and a fast transient response. They are fully fault protected against overcurrent, reverse battery and positive and negative voltage transients.

The SPX3940 is offered in 3-pin SOT-223 and TO-263 packages. For a 3A version, refer to the SPX29300 datasheet.

  • 1% output accuracy SPX3940A
  • Guaranteed 1.5A peak current
  • Low quiescent current
  • Low dropout voltage of 280mV at 1A
  • Extremely tight load and line regulation
  • Extremely fast transient response
  • Reverse battery protection
  • Internal short-circuit current limit
  • Replacement for LM3940

Documentation & Design Tools

All Types Data Sheets Application Notes Product Briefs & Brochures Symbols & Footprints
Type Title Version Date File Size
Data Sheets SPX3940 1A Low Dropout Voltage Regulator 1.0.1 July 2023 1.1 MB
Application Notes AN200, Downloading and Installing CAD Symbols and Footprints with Ultra Librarian April 2019 1.2 MB
Product Brochures Power Management Brochure R01 November 2024 2.4 MB
Product FAQs SPX3940 FAQ 1.0.0 October 2006 169.8 KB
Symbols & Footprints SPX3940AM3-L-3-3 and SPX3940AM3-L-3-3/TR CAD File (.bxl) September 2018 24.9 KB
Symbols & Footprints SPX3940AM3-L-5-0/TR CAD File (.bxl) September 2018 24.9 KB
Symbols & Footprints SPX3940AT-L-3-3/TR CAD File (.bxl) September 2018 17.7 KB
Symbols & Footprints SPX3940M3-L-2-5/TR CAD File (.bxl) September 2018 24.9 KB
Symbols & Footprints SPX3940M3-L-5-0/TR CAD File (.bxl) September 2018 24.9 KB
Symbols & Footprints SPX3940T-L-3-3/TR CAD File (.bxl) September 2018 17.7 KB
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Quality & RoHS

Part Number RoHS | Exempt RoHS Halogen Free REACH TSCA MSL Rating / Peak Reflow Package
SPX3940AM3-L-3-3 N Y Y Y Y L1 / 260ᵒC SOT-223-3
SPX3940AM3-L-3-3/TR N Y Y Y Y L1 / 260ᵒC SOT-223-3
SPX3940AM3-L-5-0/TR N Y Y Y Y L1 / 260ᵒC SOT-223-3
SPX3940M3-L-5-0/TR N Y Y Y Y L1 / 260ᵒC SOT-223-3
SPX3940M3-L-2-5/TR N Y Y Y Y L1 / 260ᵒC SOT-223-3
SPX3940AT-L-3-3/TR N Y Y Y Y L3 / 245ᵒC TO-263-3
SPX3940T-L-3-3/TR N Y Y Y Y L3 / 245ᵒC TO-263-3

Click on the links above to download the Certificate of Non-Use of Hazardous Substances.

Additional Quality Documentation may be available, please Contact Support.

Parts & Purchasing

Part Number Pkg Code Min Temp Max Temp Status Suggested Replacement Buy Now Order Samples PDN
SPX3940AM3-1-8 SOT-223-3 OBS
SPX3940AM3-1-8/TR SOT-223-3 OBS
SPX3940AM3-2-5 SOT-223-3 OBS
SPX3940AM3-2-5/TR SOT-223-3 -40 125 OBS
SPX3940AM3-3-3 SOT-223-3 -40 125 OBS
SPX3940AM3-3-3/TR SOT-223-3 -40 125 OBS
SPX3940AM3-5-0 SOT-223-3 -40 125 OBS
SPX3940AM3-5-0/TR SOT-223-3 -40 125 OBS
SPX3940AM3-L-1-8 SOT-223-3 -40 125 OBS SPX3940AM3-L-1-8/TR
SPX3940AM3-L-1-8/TR SOT-223-3 -40 125 OBS
SPX3940AM3-L-2-5 SOT-223-3 -40 125 OBS SPX3940AM3-L-2-5/TR
SPX3940AM3-L-2-5/TR SOT-223-3 -40 125 OBS SPX3940M3-L-2-5/TR
SPX3940AM3-L-3-3 SOT-223-3 -40 125 OBS SPX3940AM3-L-3-3/TR
SPX3940AM3-L-3-3/TR SOT-223-3 -40 125 Active Order
SPX3940AM3-L-5-0 SOT-223-3 -40 125 OBS SPX3940AM3-L-5-0/TR
SPX3940AM3-L-5-0/TR SOT-223-3 -40 125 Active Order
SPX3940AT-1-8 TO-263-3 -40 125 OBS
SPX3940AT-1-8/TR TO-263-3 -40 125 OBS
SPX3940AT-2-5 TO-263-3 OBS
SPX3940AT-2-5/TR TO-263-3 OBS
SPX3940AT-3-3 TO-263-3 -40 125 OBS
SPX3940AT-3-3/TR TO-263-3 -40 125 OBS
SPX3940AT-5-0 TO-263-3 OBS
SPX3940AT-5-0/TR TO-263-3 OBS
SPX3940AT-L-1-8 TO-263-3 -40 125 OBS SPX3940AT-L-1-8/TR
SPX3940AT-L-1-8/TR TO-263-3 -40 125 OBS
SPX3940AT-L-2-5 TO-263-3 -40 125 OBS SPX3940AM3-L-2-5
SPX3940AT-L-2-5/TR TO-263-3 -40 125 OBS SPX3940AM3-L-2-5/TR
SPX3940AT-L-3-3 TO-263-3 -40 125 OBS SPX3940AT-L-3-3/TR
SPX3940AT-L-3-3/TR TO-263-3 -40 125 Active Order
SPX3940AT-L-5-0 TO-263-3 -40 125 OBS SPX3940AT-L-5-0/TR
SPX3940AT-L-5-0/TR TO-263-3 -40 125 OBS
SPX3940AU-1-8 TO-220-3 OBS
SPX3940AU-2-5 TO-220-3 OBS
SPX3940AU-3-3 TO-220-3 OBS
SPX3940AU-5-0 TO-220-3 OBS
SPX3940AU-L-1-8 TO-220-3 OBS
SPX3940AU-L-2-5 TO-220-3 OBS
SPX3940AU-L-3-3 TO-220-3 OBS
SPX3940AU-L-5-0 TO-220-3 -40 125 OBS
SPX3940M3-1-8 SOT-223-3 OBS
SPX3940M3-1-8/TR SOT-223-3 OBS
SPX3940M3-2-5 SOT-223-3 -40 125 OBS
SPX3940M3-2-5/TR SOT-223-3 OBS
SPX3940M3-3-3 SOT-223-3 -40 125 OBS
SPX3940M3-3-3/TR SOT-223-3 -40 125 OBS
SPX3940M3-5-0 SOT-223-3 -40 125 OBS
SPX3940M3-5-0/TR SOT-223-3 -40 125 OBS
SPX3940M3-L-1-8 SOT-223-3 -40 125 OBS SPX3940AM3-L-1-8
SPX3940M3-L-1-8/TR SOT-223-3 -40 125 OBS SPX3940AM3-L-1-8/TR
SPX3940M3-L-2-5 SOT-223-3 -40 125 OBS SPX3940M3-L-2-5/TR
SPX3940M3-L-2-5/TR SOT-223-3 -40 125 Active Order
SPX3940M3-L-3-3 SOT-223-3 -40 125 OBS SPX3940AM3-L-3-3/TR
SPX3940M3-L-3-3/TR SOT-223-3 -40 125 OBS SPX3940AM3-L-3-3/TR
SPX3940M3-L-5-0 SOT-223-3 -40 125 OBS SPX3940M3-L-5-0/TR
SPX3940M3-L-5-0/TR SOT-223-3 -40 125 Active Order
SPX3940T-1-8 TO-263-3 OBS
SPX3940T-1-8/TR TO-263-3 OBS
SPX3940T-2-5 TO-263-3 OBS
SPX3940T-2-5/TR TO-263-3 OBS
SPX3940T-3-3 TO-263-3 -40 125 OBS
SPX3940T-3-3/TR TO-263-3 -40 125 OBS
SPX3940T-5-0 TO-263-3 OBS
SPX3940T-5-0/TR TO-263-3 OBS
SPX3940T-L-1-8 TO-263-3 -40 125 OBS SPX3940AM3-L-1-8
SPX3940T-L-1-8/TR TO-263-3 -40 125 OBS SPX3940AM3-L-1-8/TR
SPX3940T-L-2-5 TO-263-3 -40 125 OBS SPX3940AM3-L-2-5
SPX3940T-L-2-5/TR TO-263-3 -40 125 OBS SPX3940AM3-L-2-5/TR
SPX3940T-L-3-3 TO-263-3 -40 125 OBS SPX3940T-L-3-3/TR
SPX3940T-L-3-3/TR TO-263-3 -40 125 Active Order
SPX3940T-L-5-0 TO-263-3 -40 125 OBS
SPX3940T-L-5-0/TR TO-263-3 -40 125 OBS
SPX3940U-1-8 TO-220-3 OBS
SPX3940U-2-5 TO-220-3 OBS
SPX3940U-3-3 TO-220-3 -40 125 OBS
SPX3940U-5-0 TO-220-3 -40 125 OBS
SPX3940U-L-1-8 TO-220-3 OBS
SPX3940U-L-2-5 TO-220-3 OBS
SPX3940U-L-3-3 TO-220-3 OBS
SPX3940U-L-5-0 TO-220-3 -40 125 OBS
Show obsolete parts
Part Status Legend
Active - the part is released for sale, standard product.
EOL (End of Life) - the part is no longer being manufactured, there may or may not be inventory still in stock.
CF (Contact Factory) - the part is still active but customers should check with the factory for availability. Longer lead-times may apply.
PRE (Pre-introduction) - the part has not been introduced or the part number is an early version available for sample only.
OBS (Obsolete) - the part is no longer being manufactured and may not be ordered.
NRND (Not Recommended for New Designs) - the part is not recommended for new designs.

Packaging

Pkg Code Details Quantities Dimensions
SOT-223-3
  • JEDEC Reference: TO-261
  • MSL Pb-Free: L1 @ 260ºC
  • MSL SnPb Eutectic: n/a
  • ThetaJA: 62.3ºC/W
  • Bulk Pack Style: Tube
  • Quantity per Bulk Pack: 78
  • Quantity per Reel: 2500
  • Quantity per Tube: 78
  • Quantity per Tray: n/a
  • Reel Size (Dia. x Width x Pitch): 330 x 12 x 8
  • Tape & Reel Unit Orientation: Heatsink by sprocket hole
  • Dimensions: mm
  • Length: 6.50
  • Width: 3.50
  • Thickness: 1.80
  • Lead Pitch: 2.30
TO-220-3
  • JEDEC Reference: TO-220
  • MSL Pb-Free: n/a
  • MSL SnPb Eutectic: n/a
  • ThetaJA: 29.4ºC/W
  • Bulk Pack Style: Tube
  • Quantity per Bulk Pack: n/a
  • Quantity per Reel: n/a
  • Quantity per Tube: 50
  • Quantity per Tray: n/a
  • Reel Size (Dia. x Width x Pitch): n/a
  • Tape & Reel Unit Orientation: n/a
  • Dimensions: inch
  • Length: 0.355 max
  • Width: 0.420 max
  • Thickness: 0.190 max
  • Lead Pitch: 0.10
TO-263-3
  • JEDEC Reference: TO-263
  • MSL Pb-Free: L3 @ 245ºC
  • MSL SnPb Eutectic: n/a
  • ThetaJA: 31.4ºC/W
  • Bulk Pack Style: Tube
  • Quantity per Bulk Pack: n/a
  • Quantity per Reel: 500
  • Quantity per Tube: 50
  • Quantity per Tray: n/a
  • Reel Size (Dia. x Width x Pitch): 330 x 24 x 16
  • Tape & Reel Unit Orientation: Tab away from sprocket hole.
  • Dimensions: inch
  • Length: 0.380 max
  • Width: 0.420 max
  • Thickness: 0.190
  • Lead Pitch: 0.10

Notifications

Distribution Date Description File
07/17/2023 In 2023, MaxLinear will be converting all shipping labels for the parts noted from an EXAR format to MaxLinear’s label. During this transition customers may receive either label. This change affects only shipping and packing labels. This change will not affect the part number, part marking, manufacturing process or manufacturing sites. Only work in progress material will be converted. Existing inventory from MaxLinear’s warehouse, channel sales, distributor, and such, will not be converted. Hence, customers may experience receiving mixed shipments with both Exar and MaxLinear labels for some period until existing inventory of old labels is eventually cleared out. Situation is product to product with no predictable way to determine when all old labels will be exhausted. No change to product form, fit, function and reliability. ADDENDUM A: Fixed MBB label logo for DX204001 to MaxLinear logo. ADDENDUM B: Replaced ‘All other affected products outer box label’ with clearer pictures. Corrected Date Issued (from original PCN) issue date +90 days to August 30, 2023.
06/01/2023 In 2023, MaxLinear will be converting all shipping labels for the parts noted from an EXAR format to MaxLinear’s label. During this transition customers may receive either label. This change affects only shipping and packing labels. This change will not affect the part number, part marking, manufacturing process or manufacturing sites. Only work in progress material will be converted. Existing inventory from MaxLinear’s warehouse, channel sales, distributor, and such, will not be converted. Hence, customers may experience receiving mixed shipments with both Exar and MaxLinear labels for some period until existing inventory of old labels is eventually cleared out. Situation is product to product with no predictable way to determine when all old labels will be exhausted. No change to product form, fit, function and reliability.
06/01/2023 In 2023, MaxLinear will be converting all shipping labels for the parts noted from an EXAR format to MaxLinear’s label. During this transition customers may receive either label. This change affects only shipping and packing labels. This change will not affect the part number, part marking, manufacturing process or manufacturing sites. Only work in progress material will be converted. Existing inventory from MaxLinear’s warehouse, channel sales, distributor, and such, will not be converted. Hence, customers may experience receiving mixed shipments with both Exar and MaxLinear labels for some period until existing inventory of old labels is eventually cleared out. Situation is product to product with no predictable way to determine when all old labels will be exhausted. No change to product form, fit, function and reliability. ADDENDUM: Fixed MBB label logo for DX204001 to MaxLinear logo.
05/08/2019 Product Discontinuation Notice
02/27/2018 Qualification of alternate assembly subcon, JCET.
07/11/2017 Product Discontinuation Notification
04/12/2017 Qualification of alternate assembly subcon, JCET.
08/16/2016 Addition of an alternate qualified location, JCET.
07/26/2016 Product discontinuation notification. Discontinued.
02/25/2016 Alternate assembly site. Addition of an alternate assembly supplier JCET.
02/05/2016 Alternate assembly site. Addition of an alternate assembly supplier Nantong Fujitsu (China)
10/05/2015 JCET as alternate assembly site Addition of qualified alternate assembly site and material change using copper wire or gold wire.
09/09/2013 Addition of an alternate qualified SOT-223 assembly site, Carsem (Malaysia) using Hitachi CEL9240 molding compound, in addition to the current qualified assembly site, Unisem (Ipoh) using Sumitomo G600 molding compound. Material Change & Alternate Assembly Site.
02/06/2012 Packing Change: The carrier tape size changed from 16x12 mm to 12x8 mm. Quantity per reel remains the same (2.5Ku per reel). Standardization and business consolidation.
03/04/2009 Notice of Obsolescence Discontinued by Exar Corporation due to low market demand
02/28/2007 Product Obsolescence Letter and Discontinuation Notification. Discontinued.
02/02/2006 Announcing transfer of certain Power Management and Interface Products from Hillview fabrication facility to wafer foundary BCD. See attached Product List Power Management and Interface products as listed are being transfer to external wafer foundry, due to cessation of operations of the sipex Hillview Fabrication manufacturing site

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Yes. Try our Excel-based heat calculation spreadsheet ANP-03, Thermal Calculator
 
For further study, this spreadsheet is mentioned in the following helpful application note: ANP-02, Thermal Considerations for Linear Regulators 
  

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