MAX6731:Single-/Dual-/Triple-Voltage µP Supervisory Circuits with Independent Watchdog Output

Single-/Dual-/Triple-Voltage µP Supervisory Circuits with Independent Watchdog Output Monitor Down to 0.63V

The MAX6730–MAX6735 single-/dual-/triple-voltage microprocessor (µP) supervisors feature a watchdog timer and manual reset capability. The MAX6730–MAX6735 offer factory-set reset thresholds for monitoring voltages from +0.9V to +5V and an adjustable reset input for monitoring voltages down to +0.63V. The combination of these features significantly improves system reliability and accuracy when compared to separate ICs or discrete components. The active-low reset output asserts and remains asserted for the reset timeout period after all the monitored voltages exceed their respective thresholds. Multiple factory-set reset threshold combinations reduce the number of external components required. The MAX6730/MAX6731 monitor a single fixed voltage, the MAX6732/MAX6733 monitor two fixed voltages, and the MAX6734/MAX6735 monitor two fixed voltages and one adjustable voltage. All devices are offered with six minimum reset timeout periods ranging from 1.1ms to 1120ms. The MAX6730–MAX6735 feature a watchdog timer with an independent watchdog output. The watchdog timer prevents system lockup during code execution errors. A watchdog startup delay of 54s after reset asserts allows system initialization during power-up. The watchdog operates in normal mode with a 1.68s delay after initialization. The MAX6730/MAX6732/MAX6734 provide an active-low, open-drain watchdog output. The MAX6731/MAX6733/MAX6735 provide an active-low, push-pull watchdog output. Other features include a manual reset input (MAX6730/MAX6731/MAX6734/MAX6735) and push-pull reset output (MAX6731/MAX6733/MAX6735) or open-drain reset output (MAX6730/MAX6732/MAX6734). The MAX6730-MAX6733 are offered in a tiny SOT23-6 package. The MAX6734/MAX6735 are offered in a space-saving SOT23-8 package. All devices are fully specified over the extended -40°C to +85°C temperature range.

Key Features
  • VCC1 (Primary Supply) Reset Threshold Voltages from +1.575V to +4.63V
  • VCC2 (Secondary Supply) Reset Threshold Voltages from +0.79V to +3.08V
  • Adjustable RSTIN Threshold for Monitoring Voltages Down to +0.63V (MAX6734/MAX6735 Only)
  • Six Reset Timeout Options
  • Watchdog Timer with Independent Watchdog Output
    • 35s (min) Initial Watchdog Startup Period
    • 1.12s (min) Normal Watchdog Timeout Period
  • Manual Reset Input (MAX6730/MAX6731/MAX6734/MAX6735)
  • Guaranteed Reset Valid down to VCC1 or VCC2 = +0.8V
  • Push-Pull active-low RESET or Open-Drain active-low RESET Output
  • Immune to Short VCC Transients
  • Low Supply Current: 14µA (typ) at +3.6V
  • Small 6-Pin and 8-Pin SOT23 Packages
MAX6730, MAX6731, MAX6732, MAX6733, MAX6734, MAX6735: Functional Diagram
MAX6730, MAX6731, MAX6732, MAX6733, MAX6734, MAX6735: Functional Diagram
Applications/Uses
  • Computers/Servers
  • Industrial Equipment
  • Multivoltage Systems
  • Portable Battery-Powered Equipment
  • Printers and Faxes
  • Set-Top Boxes
  • Telecom/Networking Equipment
DataSheet
titleDownload file
MAX6730-MAX6735 Data SheetMAX6730-MAX6735.pdf
Parametrics
Part NumberReset Thresh.
(V)
Reset OuttRESETWatchdog FeatureWatchdog TimeoutSupervisor FeaturesReset Thresh. Accur.
(%)
ICC
(µA)
Package/PinsBudgetary
Price
min@ +25°CmaxSee Notes
MAX67301.2 to 1.8
1.8 to 2.5
2.5 to 3.3
3.3 to 5.5
Active Low
Open Drain
1ms to 15ms
15ms to 85ms
85ms to 300ms
>1s
Extended Setup Period
Input (WDI)
Input/Output (WDI/WDO)
1s to 2s
>2s
Manual Reset2.537SOT/6$1.54 @1k
MAX6731Active Low
Push-Pull
SOT/6$1.46 @1k

Part NumberInterfaceReset Thresh.
(V)
Reset OuttRESETWatchdog FeatureWatchdog TimeoutReset Thresh. Accur.
(%)
ICC
(µA)
Package/PinsBudgetary
Price
min@ +25°CmaxSee Notes
MAX6732Factory Fixed0 to 1.2
1.2 to 1.8
1.8 to 2.5
2.5 to 3.3
3.3 to 5.5
Active Low
Open Drain
1ms to 15ms
15ms to 85ms
85ms to 300ms
>1s
Extended Setup Period
Input (WDI)
Input/Output (WDI/WDO)
1s to 2s
>2s
2.537SOT/6$1.71 @1k
MAX6733Active Low
Push-Pull
SOT/6-

Part NumberInterfaceReset Thresh.
(V)
Reset OuttRESETWatchdog FeatureWatchdog TimeoutSupervisor FeaturesReset Thresh. Accur.
(%)
ICC
(µA)
Package/PinsBudgetary
Price
min@ +25°CmaxSee Notes
MAX6734Factory Fixed
R/C Adjustable
0 to 1.2
1.2 to 1.8
1.8 to 2.5
2.5 to 3.3
3.3 to 5.5
Active Low
Open Drain
1ms to 15ms
15ms to 85ms
85ms to 300ms
>1s
Extended Setup Period
Input (WDI)
Input/Output (WDI/WDO)
1s to 2s
>2s
Adjustable Reset Input
Manual Reset
2.537SOT/8$1.86 @1k
MAX6735Active Low
Push-Pull
SOT/8$3.21 @1k
Related Products
  • MAX6715:Dual/Triple Ultra-Low-Voltage SOT23 µP Supervisory Circuits
  • MAX6351:Dual/Triple-Voltage µP Supervisory Circuits
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX6731UTLD1-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTLD2-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTLD3+ActiveSOT,;6 pin;9 mm²-40°C to +85°CLead Free
MAX6731UTLD3+TActiveSOT,;6 pin;9 mm²-40°C to +85°CLead Free
MAX6731UTLD3-TNo Longer AvailableMAX6731UTLD3+TSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTLD4-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTLD5-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTLD6-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTMD1-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTMD2-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX6731UTMD3-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTMD4-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTMD5-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTMD6-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTRD1-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTRD2-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTRD3-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTRD4-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTRD5-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTRD6-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX6731UTSD1-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTSD2-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTSD3-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTSD4-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTSD5-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTSD6-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTTD1-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTTD2-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTTD3+ActiveSOT,;6 pin;9 mm²-40°C to +85°CLead Free
MAX6731UTTD3+TActiveSOT,;6 pin;9 mm²-40°C to +85°CLead Free
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX6731UTTD3-TNo Longer AvailableMAX6731UTTD3+TSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTTD4-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTTD5-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTTD6-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTVD1-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTVD2-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTVD3-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTVD4-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTVD5-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTVD6-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX6731UTWD1-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTWD2-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTWD3-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTWD4-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTWD5-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTWD6-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTYD1-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTYD2-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTYD3-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731UTYD4-TNo Longer AvailableSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6730-MAX6735.pdf MAX6735
MAX6730-MAX6735.pdf MAX6733