Low-Power Battery-Backup Circuits in Small µDFN Packages

Industry's Smallest Supervisors Offer Precision Power-Supply Monitoring with Battery Backup

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The MAX16033–MAX16040 supervisory circuits reduce the complexity and number of components required for power-supply monitoring and battery-control functions in microprocessor (µP) systems. The devices significantly improve system reliability and accuracy compared to other ICs or discrete components. The MAX16033–MAX16040 provide µP reset, backup-battery switchover, power-fail warning, watchdog, and chip-enable gating features.

The MAX16033–MAX16040 operate from supply voltages up to 5.5V. The factory-set reset threshold voltage ranges from 2.32V to 4.63V. The devices feature a manual-reset input (MAX16033/MAX16037), a watchdog timer input (MAX16034/MAX16038), a battery-on output (MAX16035/MAX16039), an auxiliary adjustable reset input (MAX16036/MAX16040), and chip-enable gating (MAX16033–MAX16036). Each device includes a power-fail comparator and offers an active-low push-pull reset or an active-low open-drain reset.

The MAX16033–MAX16040 are available in 2mm x 2mm, 8-pin or 10-pin µDFN packages and are fully specified from -40°C to +85°C.
MAX16033, MAX16034, MAX16035, MAX16036, MAX16037, MAX16038, MAX16039, MAX16040: Typical Operating Circuit MAX16033, MAX16034, MAX16035, MAX16036, MAX16037, MAX16038, MAX16039, MAX16040: Typical Operating Circuit Enlarge+

Key Features

  • Low 1.2V Operating Supply Voltage
  • Precision Monitoring of 5.0V, 3.3V, 3.0V, and 2.5V Power-Supply Voltages
  • Independent Power-Fail Comparator
  • Debounced Manual-Reset Input
  • Watchdog Timer, 1.6s Timeout
  • Battery-On Output Indicator
  • Auxiliary User-Adjustable RESETIN
  • Low 13µA Quiescent Supply Current
  • Two Available Output Structures:
    • Active-Low Push-Pull Reset
    • Active-Low Open-Drain Reset
  • Active-Low Reset Valid Down to 1.2V
  • Power-Supply Transient Immunity
  • 140ms (min) Reset Timeout Period
  • Small 2mm x 2mm, 8-Pin and 10-Pin µDFN Packages


  • Portable/Battery-Powered Equipment
  • POS Equipment
  • Critical µP/µC Power Monitoring
  • Set-Top Boxes
  • Controllers
  • Computers
  • Fax Machines
  • Industrial Control
  • Real-Time Clocks
  • Intelligent Instruments
Part NumberReset Thresh.
Reset OutICC
Oper. Temp.
maxSee Notes
1.8 to 2.5
2.5 to 3.3
3.3 to 5.5
Active Low
Open Drain
50-40 to +85
$2.37 @1k
$2.26 @1k
$3.21 @1k
See All Battery Backup Circuits (81)
Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific and version-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

Technical Documents

Tutorial 4671 Improve Sensor Performance and SNR in Pulse Oximeter Designs

Quality and Environmental Data

Request Reliability Report for: MAX16033 
Lead-Free Package Tin (Sn) Whisker Reports

CAD Symbols and Footprints

  • MAX16033LLB29+
  • MAX16033LLB29+T
  • MAX16033LLB31+T
  • MAX16033PLB29+
  • MAX16033PLB29+T
  • MAX16033PLB31+
  • MAX16033PLB31+T
  • MAX16033PLB44+T
  • Device   Fab Process   Technology   Sample size   Rejects   FIT at 25°C   FIT at 55°C  

    Note : The failure rates are summarized by technology and mapped to the associated material part numbers. The failure rates are highly dependent on the number of units tested.

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