3-Pin Microprocessor Reset Circuit


Information 3 Pin Microprocessor Reset Circuit
Package SOT23-3
Temperature Range (°C) -40 to 85
# of Channels 1
VCC MIN (V) 0.9
Reset Threshold (V) 2.3, 2.6, 2.9, 3.1, 4.6
Reset Output Active-low
Output Driver Type Push-pull
Reset Accuracy (mV) 60
Special Features
Watchdog Timeout (s) -
Reset Time Delay (ms) 140
IQ (µA) typ 1
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The SP809 is a low power microprocessor (μP) supervisory circuit used to monitor power supplies in μP and digital systems.
It provides applications with benefits of circuit reliability and low cost by eliminating external components. If the VCC supply voltage falls below preset threshold then a reset signal is asserted for at least 140ms after VCC has risen above the reset threshold.
The SP810 has been designed with a reset comparator to help identify invalid signals, which last less than 140ms. The SP810 has an active-low RESET output.

  • Ultra-low supply current 1µA (typ.)
  • Guaranteed reset valid to VCC = 0.9V
  • 140 ms minimum power-on reset pulse width
  • Internally fixed threshold 2.3V, 2.6V, 2.9V, 3.1V
  • Tight voltage threshold tolerance: 1.5%
  • Offered in a 3-pin SOT-23 package

  • Portable electronic devices
  • Electrical power meters
  • Digital still cameras
  • uP power monitoring

Documentation & Design Tools

Type Title Version Date File Size
Data Sheets SP809 3 Pin Microprocessor Supervisor Circuit 2.0.3 July 2021 735.4 KB
Application Notes AN200, Downloading and Installing CAD Symbols and Footprints with Ultra Librarian April 2019 1.2 MB
Product Flyers Power Management & Interface Products for Cable, Satellite and IP STB/Home Gateway March 2018 2 MB
Design Solutions DS-23, Drop-In Replacing MAX803/809/810 With Sipex 3-Pin Microprocessor Supervisory Reset Solutions November 2007 27.5 KB
Product Brochures Power Management Brochure October 2020 2.4 MB
Symbols & Footprints SP809EK-L-2-3/TR CAD File (.bxl) September 2018 65.9 KB
Symbols & Footprints SP809EK-L-2-6/TR CAD File (.bxl) September 2018 66.4 KB
Symbols & Footprints SP809EK-L-2-9/TR CAD File (.bxl) September 2018 65.9 KB
Symbols & Footprints SP809NEK-L-3-1/TR CAD File (.bxl) September 2018 65.9 KB
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Quality & RoHS

Part Number RoHS | Exempt RoHS Halogen Free REACH TSCA MSL Rating / Peak Reflow Package
SP809EK-L-2-3/TR N Y Y Y Y SOT-23-3 OPT2 Y
SP809EK-L-2-6/TR N Y Y Y Y SOT-23-3 OPT2 Y
SP809EK-L-2-9/TR N Y Y Y Y SOT-23-3 OPT2 Y
SP809NEK-L-3-1/TR N Y Y Y Y SOT-23-3 OPT2 Y

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
SP809EK-2-3 SOT-23-3 OPT2 -40 85 OBS
SP809EK-2-3/TR SOT-23-3 OPT2 -40 85 OBS
SP809EK-2-6 SOT-23-3 OPT2 -40 85 OBS
SP809EK-2-6/TR SOT-23-3 OPT2 -40 85 OBS
SP809EK-2-9 SOT-23-3 OPT2 -40 85 OBS
SP809EK-2-9/TR SOT-23-3 OPT2 -40 85 OBS
SP809EK-3-1 SOT-23-3 OPT2 -40 85 OBS
SP809EK-3-1/TR SOT-23-3 OPT2 -40 85 OBS
SP809EK-4-0 SOT-23-3 OPT2 -40 85 OBS
SP809EK-4-0/TR SOT-23-3 OPT2 -40 85 OBS
SP809EK-4-4 SOT-23-3 OPT2 -40 85 OBS
SP809EK-4-4/TR SOT-23-3 OPT2 -40 85 OBS
SP809EK-4-6 SOT-23-3 OPT2 -40 85 OBS
SP809EK-4-6/TR SOT-23-3 OPT2 -40 85 OBS
SP809EK-L-2-3 SOT-23-3 OPT2 -40 85 OBS
SP809EK-L-2-3/TR SOT-23-3 OPT2 -40 85 Active Order
SP809EK-L-2-6 SOT-23-3 OPT2 -40 85 OBS
SP809EK-L-2-6/TR SOT-23-3 OPT2 -40 85 Active Order
SP809EK-L-2-9 SOT-23-3 OPT2 -40 85 OBS
SP809EK-L-2-9/TR SOT-23-3 OPT2 -40 85 Active Order
SP809EK-L-3-1 SOT-23-3 OPT2 -40 85 OBS
SP809EK-L-3-1/TR SOT-23-3 OPT2 -40 85 OBS SP809NEK-L-3-1/TR
SP809EK-L-4-0 SOT-23-3 OPT2 -40 85 OBS
SP809EK-L-4-0/TR SOT-23-3 OPT2 -40 85 OBS
SP809EK-L-4-4 SOT-23-3 OPT2 -40 85 OBS
SP809EK-L-4-4/TR SOT-23-3 OPT2 -40 85 OBS
SP809EK-L-4-6 SOT-23-3 OPT2 -40 85 OBS
SP809EK-L-4-6/TR SOT-23-3 OPT2 -40 85 OBS
SP809NEK-2-3 SOT-23-3 OPT2 -40 85 OBS
SP809NEK-2-3/TR SOT-23-3 OPT2 -40 85 OBS
SP809NEK-2-6 SOT-23-3 OPT2 -40 85 OBS
SP809NEK-2-6/TR SOT-23-3 OPT2 -40 85 OBS
SP809NEK-2-9 SOT-23-3 OPT2 -40 85 OBS
SP809NEK-2-9/TR SOT-23-3 OPT2 -40 85 OBS
SP809NEK-3-1 SOT-23-3 OPT2 -40 85 OBS
SP809NEK-3-1/TR SOT-23-3 OPT2 -40 85 OBS
SP809NEK-4-0 SOT-23-3 OPT2 -40 85 OBS
SP809NEK-4-0/TR SOT-23-3 OPT2 -40 85 OBS
SP809NEK-4-4 SOT-23-3 OPT2 -40 85 OBS
SP809NEK-4-4/TR SOT-23-3 OPT2 -40 85 OBS
SP809NEK-4-6 SOT-23-3 OPT2 -40 85 OBS
SP809NEK-4-6/TR SOT-23-3 OPT2 -40 85 OBS
SP809NEK-L-2-3 SOT-23-3 OPT2 -40 85 OBS
SP809NEK-L-2-3/TR SOT-23-3 OPT2 -40 85 OBS SP809EK-L-2-3/TR
SP809NEK-L-2-6 SOT-23-3 OPT2 -40 85 OBS
SP809NEK-L-2-6/TR SOT-23-3 OPT2 -40 85 OBS
SP809NEK-L-2-9 SOT-23-3 OPT2 -40 85 OBS
SP809NEK-L-2-9/TR SOT-23-3 OPT2 -40 85 OBS SP809EK-L-2-9/TR
SP809NEK-L-3-1 SOT-23-3 OPT2 -40 85 OBS
SP809NEK-L-3-1/TR SOT-23-3 OPT2 -40 85 Active Order
SP809NEK-L-4-0 SOT-23-3 OPT2 -40 85 OBS
SP809NEK-L-4-0/TR SOT-23-3 OPT2 -40 85 OBS
SP809NEK-L-4-4 SOT-23-3 OPT2 -40 85 OBS
SP809NEK-L-4-4/TR SOT-23-3 OPT2 -40 85 OBS
SP809NEK-L-4-6 SOT-23-3 OPT2 -40 85 OBS
SP809NEK-L-4-6/TR SOT-23-3 OPT2 -40 85 OBS
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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.


Pkg Code Details Quantities Dimensions PDF
SOT-23-3 OPT2
  • JEDEC Reference: TO-236
  • MSL Pb-Free: L1 @ 260°C
  • MSL SnPb Eutectic:
  • ThetaJA:
  • 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): 180 x 8 x 4
  • Tape & Reel Unit Orientation: Single Pin at sprocket
  • Dimensions: mm
  • Length: 2.9
  • Width: 1.6
  • Thickness: 1.45
  • Lead Pitch: 0.95


Distribution Date Description File
02/04/2021 MaxLinear has qualified material changes in the products listed to improve package manufacturing efficiency. The datasheet will be updated to accommodate these changes. There is no change to form, fit or electrical function.
02/16/2018 Standard tape and reel quantity will change from 2500 pieces to 3000 pieces for SOT23-3L/5L/6L. Addendum: Remove SOT-89 parts from affected products list.
07/11/2017 Product Discontinuation Notification
01/12/2017 Standard tape and reel quantity will change from 2500 pieces to 3000 pieces for SOT23-3L/5L/6L.
08/16/2012 Material change: Bond wire is changed from gold to copper. To update our manufacturing to be compatible with current industry standards and maintain capacity.
06/02/2010 Add an alternative qualified assembly and test supplier. Capacity enhancement.
10/21/2009 Material Change Enhance Pb-free package to be Pb-free and halogen free package.
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.

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