STWD100:Watchdog

The STWD100 watchdog timer circuits are self-contained devices which prevent system failures that are caused by certain types of hardware errors (such as, non-responding peripherals and bus contention) or software errors (such as a bad code jump and a code stuck in loop).

The STWD100 watchdog timer has an input, WDI, and an output, WDO. The input is used to clear the internal watchdog timer periodically within the specified timeout period, twd. While the system is operating correctly, it periodically toggles the watchdog input, WDI. If the system fails, the watchdog timer is not reset, a system alert is generated and the watchdog output, WDO, is asserted.

The STWD100 circuit also has an enable pin, EN, which can enable or disable the watchdog functionality. The EN pin is connected to the internal pull-down resistor. The device is enabled if the EN pin is left floating.

Key Features

  • Current consumption 13 µA typ.
  • Available watchdog timeout periods are 3.4 ms, 6.3 ms, 102 ms, and 1.6 s
  • Chip enable input
  • Open drain or push-pullWDO output
  • Operating temperature range: –40 to 125 °C
  • Packages: SOT23-5 and SC70-5 (SOT323-5)
  • ESD performance
    • HBM: 2000 V
    • RCDM: 1000 V
  • Automotive qualified
Product Specifications
DescriptionVersionSize
DS5579: Watchdog timer circuit10.01019 KB
Technical Notes & Articles
DescriptionVersionSize
TN0941: Reset and supervisor ICs: frequently asked questions (FAQ)1.0328 KB
Presentations
DescriptionVersionSize
VMA automotive applications1 MB
Flyers
DescriptionVersionSize
Resets and supervisors - portfolio overview1.01 MB
ST automotive solutions - High-performance analog products1.01 MB
Watchdog ICs For automotive applications487 KB
Sample & Buy
Part NumberPackagePacking TypeOperating Temperature (°C) (min)Operating Temperature (°C) (max)Unit Price (US$) *QuantityECCN (EU)ECCN (US)Country of Origin
STWD100YNYWY3FSOT23-5LTape And Reel-401250.621000NECEAR99MALAYSIA
STWD100NPWY3FSOT23-5LTape And Reel-401250.521000NECEAR99MALAYSIA
STWD100YNWWY3FSOT23-5LTape And Reel-401250.6211000NECEAR99MALAYSIA
STWD100NWWY3FSOT23-5LTape And Reel-401250.5171000NECEAR99MALAYSIA
STWD100NYWY3FSOT23-5LTape And Reel-401250.521000NECEAR99MALAYSIA
STWD100PYW83FSOT323-5LTape And Reel-401250.521000NECEAR99MALAYSIA
STWD100YNPWY3FSOT23-5LTape And Reel-401250.621000NECEAR99MALAYSIA
Quality & Reliability
Part NumberPackageGradeRoHS Compliance GradeMaterial Declaration**
STWD100YNYWY3FSOT23-5LAutomotiveEcopack3md_wy-wspc-sot-wspc-23-5_dywy-wspc-n6vay0y_vers2_sdm_signed.pdf
md_wy-wspc-sot-wspc-23-5_dywy-wspc-n6vay0y_vers2_sdm.xml
STWD100NPWY3FSOT23-5LIndustrialEcopack3md_wy-wspc-sot-wspc-23-5_dzwyn6vaa00-wspc-(stwd100npwy3f).pdf
md_wy-wspc-sot-wspc-23-5_dzwyn6vaa00-wspc-(stwd100npwy3f).xml
STWD100YNWWY3FSOT23-5LAutomotiveEcopack3md_wy-wspc-sot-wspc-23-5_3wwyn6vaw0y-wspc-(stwd100ynwwy3f)-wspc-ver2_signed.pdf
md_wy-wspc-sot-wspc-23-5_3wwyn6vaw0y-wspc-(stwd100ynwwy3f)-wspc-ver2.xml
STWD100NWWY3FSOT23-5LIndustrialEcopack3
STWD100NYWY3FSOT23-5LIndustrialEcopack3
STWD100PYW83FSOT323-5LIndustrialEcopack3
STWD100YNPWY3FSOT23-5LAutomotiveEcopack3
Watchdog timer circuit STWD100
circuit_diagram_14134_thumbnail.png STWD100
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md_wy-wspc-sot-wspc-23-5_dywy-wspc-n6vay0y_vers2_sdm_signed.pdf STWD100
md_wy-wspc-sot-wspc-23-5_dywy-wspc-n6vay0y_vers2_sdm.xml STWD100
md_wy-wspc-sot-wspc-23-5_dzwyn6vaa00-wspc-(stwd100npwy3f).pdf STWD100
md_wy-wspc-sot-wspc-23-5_dzwyn6vaa00-wspc-(stwd100npwy3f).xml STWD100
md_wy-wspc-sot-wspc-23-5_3wwyn6vaw0y-wspc-(stwd100ynwwy3f)-wspc-ver2_signed.pdf STWD100
md_wy-wspc-sot-wspc-23-5_3wwyn6vaw0y-wspc-(stwd100ynwwy3f)-wspc-ver2.xml STWD100