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Low-Voltage SOT23 µP Supervisors with Manual Reset and Watchdog Timer

Product Details

Key Features

Parametric specs for Supervisors (1 Monitored Voltage)
Reset Thresh. (V) 1.2 to 1.8
1.8 to 2.5
2.5 to 3.3
3.3 to 5.5
Reset Thresh. Accur. (%) (@ +25°C) 2.5
Reset Out Active High
Push-Pull
tRESET (min) 85ms to 300ms
Watchdog Feature Input (WDI)
Watchdog Timeout 1s to 2s
Supervisor Features Manual Reset
ICC (µA) (max) 16
Package/Pins SOT23/5
Budgetary
Price (See Notes)
1.73
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Simplified Block Diagram

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Parameters

Parametric specs for Supervisors (1 Monitored Voltage)
Reset Thresh. (V) 1.2 to 1.8
1.8 to 2.5
2.5 to 3.3
3.3 to 5.5
Reset Thresh. Accur. (%) (@ +25°C) 2.5
Reset Out Active High
Push-Pull
tRESET (min) 85ms to 300ms
Watchdog Feature Input (WDI)
Watchdog Timeout 1s to 2s
Supervisor Features Manual Reset
ICC (µA) (max) 16
Package/Pins SOT23/5
Budgetary
Price (See Notes)
1.73

Key Features

  • Monitors +1.8V, +2.5V, +3.0V, +3.3V, +5.0V Supplies
  • 140ms (min) Reset Timeout Delay
  • 1.6s Watchdog Timeout Period (MAX6821/MAX6822/MAX6823/MAX6824)
  • Manual Reset Input (MAX6821/MAX6822/MAX6823/MAX6825)
  • Three Reset Output Options
    • Push-Pull Active-Low RESET
    • Push-Pull RESET
    • Open-Drain Active-Low RESET
  • Guaranteed Reset Valid to VCC = +1.0V
  • Immune to Short Negative VCC Transients
  • No External Components
  • Small 5-Pin SOT23 Packages

Applications/Uses

  • Computers and Controllers
  • Critical µP Monitoring
  • Embedded Controllers
  • Intelligent Instruments
  • Portable Battery-Powered Equipment
  • Set-Top Boxes

Description

The MAX6821—MAX6825 are low-voltage microprocessor (µP) supervisory circuits that combine voltage monitoring, watchdog timer, and manual reset input functions in a 5-pin SOT23 package. Microprocessor supervisory circuits significantly improve system reliability and accuracy compared to separate ICs or discrete components. These devices assert a reset signal whenever the monitored voltage drops below its preset threshold, keeping it asserted for a minimum timeout period after VCC rises above the threshold. In addition, a watchdog timer monitors against code execution errors. A debounced manual reset is also available. The MAX6821—MAX6825 monitor voltages from +1.8V to +5.0V. These outputs are guaranteed to be in the correct state for VCC down to +1.0V.

Nine preprogrammed reset threshold voltages are available (see the Threshold Suffix Guide). The MAX6821, MAX6822, and MAX6823 all have a manual reset input and a watchdog timer. The MAX6821 has push-pull RESET, the MAX6822 has open-drain active-low RESET, and the MAX6823 has push-pull active-low RESET. The MAX6824 has a watchdog timer and both push-pull active-low RESET and push-pull RESET. The MAX6825 has a manual reset input and both push-pull active-low RESET and push-pull RESET. The Selector Guide explains the functions offered in this series of parts.

Simplified Block Diagram

MAX6821, MAX6822, MAX6823, MAX6824, MAX6825: Typical Operating Circuit MAX6821, MAX6822, MAX6823, MAX6824, MAX6825: Typical Operating Circuit Zoom icon

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .