Precision Adjustable Shunt Regulator
Data Sheet


The SPX431A is a three-terminal adjustable shunt voltage regulator providing a highly accurate bandgap reference.

The SPX431A acts as an open-loop error amplifier with a 2.5V temperature compensation reference. The SPX431A has thermal stability, wide operating current of 150mA and broad temperature range of -40°C to 125°C, making it suitable for a variety of applications which require a low-cost, high performance solution. The SPX431A tolerance of 0.5% is proven to be sufficient to overcome all other errors in the system to virtually eliminate the need for trimming in the power supply manufacturer's assembly line and contribute a significant cost savings. The output voltage may be adjusted to any value between VREF and 36 volts with two external resistors.

The SPX431A is available in RoHS compliant, lead free TO-92 and SOT-89 packages.


  • 0.5% precise output voltage
    • Adjustable up to 36V
  • Wide operating current
    • 1mA to 150mA
  • Low temperature coefficient at 30ppm/°C
  • Extended temperature range
    • -40°C to 125°C
  • Improved replacment for TL431
  • RoHS compliant, lead free TO-92 and SOT-89 packages


  • Charger
  • Switching power supplies
  • Graphics card
  • Monitors, VCR, TV

Design Tools

Symbols & Footprints


Pkg Code Details Quantities Dimensions PDF
  • JEDEC Reference: TO-243
  • MSL Pb-Free: L2 @ 260ºC
  • MSL SnPb Eutectic: n/a
  • ThetaJA: 107.1ºC/W
  • Bulk Pack Style: Canister
  • Quantity per Bulk Pack: n/a
  • Quantity per Reel: 2500
  • Quantity per Tube: n/a
  • Quantity per Tray: n/a
  • Reel Size (Dia. x Width x Pitch): 330 x 12 x 8
  • Tape & Reel Unit Orientation: Tab at sprocket hole.
  • Dimensions: mm
  • Length: 4.60 max
  • Width: 2.60 max
  • Thickness: 1.60
  • Lead Pitch: 1.50
  • JEDEC Reference: n/a
  • MSL Pb-Free: n/a
  • MSL SnPb Eutectic: n/a
  • ThetaJA: 131.9ºC/W
  • Bulk Pack Style: Ammo
  • Quantity per Bulk Pack: n/a
  • Quantity per Reel: 2000
  • Quantity per Tube: n/a
  • Quantity per Tray: n/a
  • Reel Size (Dia. x Width x Pitch): Ammo
  • Tape & Reel Unit Orientation: Ammopack
  • Dimensions: inch
  • Length: 0.195 max
  • Width: 0.195 max
  • Thickness: 0.155 max
  • Lead Pitch: 0.055

Parts & Purchasing

Part Number Pkg Code Min Temp Max Temp Status Buy Now Order Samples
SPX431AM1-L/TR SOT-89-3 -40 125 Active Order
SPX431AN-L/TR TO-92-3 -40 125 OBS Suggested:
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.

Quality & Environmental Data

Part Number RoHS | Exempt RoHS Halogen Free REACH MSL Rating / Peak Reflow Package
SPX431AM1-L/TR N Y Y Y L3 / 260ᵒC SOT-89

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

Additional Quality Documentation may be available, please Contact Support.
Distribution Date Description File
07/11/2017 Product Discontinuation Notification
02/19/2016 Material change. Qualified copper wire bonding assembly.
05/22/2013 Addition of JCET as an alternate qualified assembly and test location. Process & material change.
05/07/2013 Addition of alternate Assembly and Test Site JCET (Chuzhou). Process change.
08/07/2009 Notice of Obsolescence – Selected Power Management Parts Discontinued due to low market demand, effective immediately.
09/10/2008 Notice of Obsolescence –Selected Power Management Parts This is notification that the Power Management products listed on the attached page have been discontinued by Exar Corporation due to low market demand, effective immediately.
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


Search our list of FAQs for answers to common technical questions.
For material content, environmental, quality and reliability questions review the Quality tab or visit our Quality page.
For ordering information and general customer service visit our Contact Us page.

Frequently Asked Questions

The best way to determine this is to go to maxlinear.com and type the part into the search function. At or near the top of the results you should see something that looks like:

In this example, we looked for XRA1201. Click on part number header or on the link at the bottom of the result.  This brings you to the product page. For example:


Click on Parts & Purchasing, highlighted with the blue arrow above. The screen changes to:


Notice the status column and the “Show obsolete parts” link.  A legend tells you the definition of the different statuses. Click on the “Show obsolete parts” link to see EOL or OBS part numbers along with the Active part numbers, the legend still present:


Another method to find out if a part is OBS or EOL is to click on SUPPORT at the top:


And then Product Change Notifications:


Type the part into the search, and click on one of the part numbers from the drop down menu. Then you can look for the Product Discontinuation Notice, which generally is at the top of the list, for example:


If you see this, it tells you that this particular orderable part has been discontinued and when the last order date is, or was. If you click on the file, then you can view the notice we sent about this if you purchased the part in the recent past. It may also advise of a replacement part. When an orderable part first becomes discontinued, Product Discontinuation Notices are sent are sent to those who have purchased the parts in the recent past, if purchased directly, with a dated opportunity to place a last order.

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