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Low-Cost, µP Supervisory Circuits

Low-Cost Reset + Watchdog ICs

Product Details

Key Features

Parametric specs for Supervisors (1 Monitored Voltage)
Reset Thresh. (V) 3.3 to 5.5
Reset Thresh. Accur. (%) (@ +25°C) 2.5
Reset Out Active Low
Push-Pull
tRESET (min) 85ms to 300ms
Watchdog Feature Input (WDI)
Input/Output (WDI/WDO)
Watchdog Timeout 1s to 2s
Supervisor Features Adjustable Reset Input
Manual Reset
Power Fail Comparator/Low Battery Detect
ICC (µA) (max) 350
Package/Pins CDIP/8
PDIP/8
SOIC (N)/8
UMAX/8
Budgetary
Price (See Notes)
3.1
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Simplified Block Diagram

Technical Docs

Data Sheet Low-Cost, µP Supervisory Circuits Aug 29, 2018

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Parameters

Parametric specs for Supervisors (1 Monitored Voltage)
Reset Thresh. (V) 3.3 to 5.5
Reset Thresh. Accur. (%) (@ +25°C) 2.5
Reset Out Active Low
Push-Pull
tRESET (min) 85ms to 300ms
Watchdog Feature Input (WDI)
Input/Output (WDI/WDO)
Watchdog Timeout 1s to 2s
Supervisor Features Adjustable Reset Input
Manual Reset
Power Fail Comparator/Low Battery Detect
ICC (µA) (max) 350
Package/Pins CDIP/8
PDIP/8
SOIC (N)/8
UMAX/8
Budgetary
Price (See Notes)
3.1

Key Features

  • Supervisory-Function Integration Significantly Improves System Reliability While Reducing Board Space
    • µMAX Package
    • Guaranteed Active Low RESET Valid at VCC = 1V
      • 200ms Reset Pulse Width
      • Debounced TTL/CMOS-Compatible Manual-Reset Input
      • Active-High Reset Output (MAX707/MAX708/MAX813L)
    • Precision-Supply Voltage Monitor
      • 4.65V (MAX705/MAX707/MAX813L)
      • 4.40V (MAX706/MAX708)
    • Voltage Monitor for Power-Fail or Low-Battery Warning

Applications/Uses

  • Computers
  • Controllers
  • Critical µP Power Monitoring
  • Intelligent Instruments

Description

The MAX705–MAX708/MAX813L microprocessor (µP) supervisory circuits reduce the complexity and number of components required to monitor power-supply and battery functions in µP systems. These devices significantly improve system reliability and accuracy compared to separate ICs or discrete components.

The MAX705/MAX706/MAX813L provide four functions:

  1. A reset output during power-up, power-down, and brownout conditions.
  2. An independent watchdog output that goes low if the watchdog input has not been toggled within 1.6 seconds.
  3. A 1.25V threshold detector for power-fail warning, low-battery detection, or for monitoring a power supply other than +5V.
  4. An active-low manual-reset input.

The MAX707/MAX708 are the same as the MAX705/MAX706, except an active-high reset is substituted for the watchdog timer. The MAX813L is the same as the MAX705, except RESET is provided instead of active-low RESET.

Two supply-voltage monitor levels are available: The MAX705/MAX707/MAX813L generate a reset pulse when the supply voltage drops below 4.65V, while the MAX706/MAX708 generate a reset pulse below 4.40V. All four parts are available in 8-pin DIP, SO and µMAX® packages.

Simplified Block Diagram

MAX705, MAX706, MAX707, MAX708, MAX813, MAX813L: Typical Operating Circuit MAX705, MAX706, MAX707, MAX708, MAX813, MAX813L: Typical Operating Circuit Zoom icon

Technical Docs

Data Sheet Low-Cost, µP Supervisory Circuits Aug 29, 2018

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 .