3-Pin Microprocessor Reset Circuit


The SP810 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-high RESET output.
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  • Ultra-low supply current 1µA (typ.)
  • Guaranteed reset valid to VCC = 0.9V
  • 140 ms minimum power-on reset pulse width
  • Internally fixed threshold 2.6V
  • 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

Design Tools

Reference Designs


Pkg Code Details Quantities Dimensions PDF
  • JEDEC Reference: TO-236
  • MSL Pb-Free: L1 @ 260ºC
  • MSL SnPb Eutectic: n/a
  • ThetaJA: n/a
  • Bulk Pack Style: Canister
  • Quantity per Bulk Pack: n/a
  • Quantity per Reel: 3000
  • 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 hole.
  • Dimensions: mm
  • Length: 2.90
  • Width: 1.30
  • Thickness: 0.95
  • Lead Pitch: 0.95
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: n/a
  • Quantity per Tube: n/a
  • Quantity per Tray: n/a
  • Reel Size (Dia. x Width x Pitch): 180x8x4
  • Tape & Reel Unit Orientation: Single Pin at sprocket ho
  • Dimensions: mm
  • Length: 2.9
  • Width: 1.6
  • Thickness: 1.15
  • Lead Pitch: 1.9

Parts & Purchasing

Part Number Pkg Code RoHS Min Temp Max Temp Status Buy Now Order Samples
SP8100CY 0 70 OBS
SP8100CY/TR 0 70 OBS
SP8100EY 0 70 OBS
SP8100EY/TR 0 70 OBS
SP8101CY 0 70 OBS
SP8101CY/TR 0 70 OBS
SP8101EY 0 70 OBS
SP8101EY/TR 0 70 OBS
SP810EK-2-3 SOT-23-3 -40 85 OBS
SP810EK-2-3/TR SOT-23-3 -40 85 OBS
SP810EK-2-6 SOT-23-3 -40 85 OBS
SP810EK-2-6/TR SOT-23-3 -40 85 OBS
SP810EK-2-9 SOT-23-3 -40 85 OBS
SP810EK-2-9/TR SOT-23-3 -40 85 OBS
SP810EK-3-1 SOT-23-3 -40 85 OBS
SP810EK-3-1/TR SOT-23-3 -40 85 OBS
SP810EK-4-0 SOT-23-3 -40 85 OBS
SP810EK-4-0/TR SOT-23-3 -40 85 OBS
SP810EK-4-4 SOT-23-3 -40 85 OBS
SP810EK-4-4/TR SOT-23-3 -40 85 OBS
SP810EK-4-6 SOT-23-3 -40 85 OBS
SP810EK-4-6/TR SOT-23-3 -40 85 OBS
SP810EK-L-2-3 SOT-23-3 -40 85 OBS
SP810EK-L-2-3/TR SOT-23-3 -40 85 OBS
SP810EK-L-2-6 SOT-23-3 -40 85 OBS
SP810EK-L-2-6/TR SOT-23-3 -40 85 OBS Suggested:
SP810EK-L-2-9 SOT-23-3 -40 85 OBS
SP810EK-L-2-9/TR SOT-23-3 -40 85 OBS
SP810EK-L-3-1 SOT-23-3 -40 85 OBS
SP810EK-L-3-1/TR SOT-23-3 -40 85 OBS
SP810EK-L-4-0 SOT-23-3 -40 85 OBS
SP810EK-L-4-0/TR SOT-23-3 -40 85 OBS
SP810EK-L-4-4 SOT-23-3 -40 85 OBS
SP810EK-L-4-4/TR SOT-23-3 OPT2 -40 85 EOL
SP810EK-L-4-6 SOT-23-3 -40 85 OBS
SP810EK-L-4-6/TR SOT-23-3 -40 85 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.
Distribution Date Description File
07/11/2017 Product Discontinuation Notification PDN_17-0623-01-1033.pdf
01/12/2017 Standard tape and reel quantity will change from 2500 pieces to 3000 pieces for SOT23-3L/5L/6L. PCN 16-1146-02 Reel size change-1033.pdf
07/26/2016 Product discontinuation notification. Discontinued. PDN 16-0626-01-1033.pdf
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. PCN_12-0522-01-1033.pdf
06/02/2010 Add an alternative qualified assembly and test supplier. Capacity enhancement. PCN_10-0510-01-1033.pdf
10/21/2009 Material Change Enhance Pb-free package to be Pb-free and halogen free package. PCN_091007-01-1033.pdf
08/07/2009 Notice of Obsolescence – Selected Power Management Parts Discontinued due to low market demand, effective immediately. PDN_090807-01-1033-1033.pdf
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. PDN_080910-01-1033.pdf
02/28/2007 Product Obsolescence Letter and Discontinuation Notification. Discontinued. POL_022807-1033.pdf