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  2. Power Management
  3. Battery Management
  4. Battery Backup IC
  5. MAX791


Features and Benefits

  • Precision 4.65V Voltage Monitoring
  • 200ms Power-OK/Reset Time Delay
  • Independent Watchdog Timer-Preset or Adjustable
  • 1µA Standby Current
  • Power Switching
    • 250mA Output in VCC Mode
    • 25mA Output in Battery-Backup Mode
  • On-Board Gating of Chip-Enable Signals
    • Memory Write-Cycle Completion
    • 6ns CE Gate Propagation Delay
  • MaxCap™ or SuperCap™ Compatible
  • Voltage Monitor for Power-Fail or Low-Battery Warning
  • Backup-Battery Monitor
  • Guaranteed RESET-bar Valid to VCC = 1V

Product Details

The MAX791 microprocessor (µP) supervisory circuit reduces the complexity and number of components needed to monitor power-supply and battery-control functions in µP systems. The 50µA supply current makes the MAX791 ideal for use in portable equipment, while the 6ns chip-enable propagation delay and 250mA output capability (25mA in battery-backup mode) make it suitable for larger, higher-performance equipment.

The MAX791 comes in 16-pin DIP and narrow SO packages and provides the following functions:

  1. µP reset-RESET-bar output is asserted during power-up, power-down, and brownout conditions, and is guaranteed to be in the correct state for VCC down to 1V, even with no battery in the circuit.
  2. Manual-reset input.
  3. A 1.25V threshold detector provides for power-fail warning and low-battery detection, or monitors a power supply other than +5V.
  4. Two-stage power-fail warning-a separate low-line comparator compares VCC to a threshold 150mV above the reset threshold.
  5. Backup-battery switchover for CMOS RAM, real-time clocks, µPs, or other low-power logic.
  6. Software monitoring of backup-battery voltage.
  7. A watchdog-fault output is asserted if the watchdog input has not been toggled within either a preset or an adjustable timeout period.
  8. Write protection of CMOS RAM or EEPROM.
  9. Pulsed watchdog output, to give advance warning of impending WDO-bar assertion caused by watchdog timeout.


  • Computers: Desktop, Workstation, Server
  • Controllers
  • Critical µP Monitoring
  • Intelligent Instruments
  • Portable Battery-Powered Equipment

Product Categories

Product Lifecycle icon-recommended Production

At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.

Product Recommendations

MAX791 Companion Parts

Recommended Related Parts

Design Resources

ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well.  "Zero defects" for shipped products is always our goal.View our quality and reliability program and certifications for more information.

Part Number Material Declaration Reliability Data Pin/Package Drawing CAD Symbols, Footprints & 3D Models
MAX791CPE+ Material Declaration Reliability Data Plastic Dual-In-Line, Narrow (0.3in)
MAX791CSE+ Material Declaration Reliability Data 16-SOIC_N-150_MIL
MAX791CSE+T Material Declaration Reliability Data 16-SOIC_N-150_MIL
MAX791EPE+ Material Declaration Reliability Data Plastic Dual-In-Line, Narrow (0.3in)
MAX791ESE+ Material Declaration Reliability Data 16-SOIC_N-150_MIL
MAX791ESE+T Material Declaration Reliability Data 16-SOIC_N-150_MIL
MAX791MJE Material Declaration Reliability Data Ceramic Dual-In-Line, Narrow (0.3in)
Wafer Fabrication Data MAX791 Reliability Data

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