MAX6731A: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 MAX6730A–MAX6735A single-/dual-/triple-voltage microprocessor (µP) supervisors feature a watchdog timer and manual reset capability. The MAX6730A–MAX6735A 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 MAX6730A/MAX6731A monitor a single fixed voltage, the MAX6732A/MAX6733A monitor two fixed voltages, and the MAX6734A/MAX6735A 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 MAX6730A–MAX6735A 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 MAX6730A/MAX6732A/MAX6734A provide an active-low, open-drain watchdog output. The MAX6731A/MAX6733A/MAX6735A provide an active-low, push-pull watchdog output. Other features include a manual reset input (MAX6730A/MAX6731A/MAX6734A/MAX6735A) and push-pull reset output (MAX6731A/MAX6733A/MAX6735A) or open-drain reset output (MAX6730A/MAX6732A/MAX6734A). The MAX6730A–MAX6733A are offered in a tiny 6-pin SOT23 package. The MAX6734A/MAX6735A are offered in an 8-pin, space-saving SOT23 package. All devices are fully specified over the extended -40°C to +125°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 (MAX6734A/MAX6735A 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 (MAX6730A/MAX6731A/MAX6734A/MAX6735A)
  • 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
MAX6730A, MAX6731A, MAX6732A, MAX6733A, MAX6734A, MAX6735A: Typical Operating Circuit
MAX6730A, MAX6731A, MAX6732A, MAX6733A, MAX6734A, MAX6735A: Typical Operating Circuit
Applications/Uses
  • Computers/Servers
  • Industrial Equipment
  • Multivoltage Systems
  • Portable Battery-Powered Equipment
  • Printers/Fax Machines
  • Set-Top Boxes
  • Telecom/Networking Equipment
DataSheet
titleDownload file
MAX6730A-MAX6735A Data SheetMAX6730A-MAX6735A.pdf
Parametrics
Part NumberReset Thresh.
(V)
Reset OuttRESETWatchdog FeatureWatchdog TimeoutSupervisor FeaturesReset Thresh. Accur.
(%)
ICC
(µA)
Package/PinsBudgetary
Price
min@ +25°CmaxSee Notes
MAX6730A1.2 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 Reset2.539SOT/6$1.46 @1k
MAX6731AActive Low
Push-Pull
SOT/6

Part NumberInterfaceReset Thresh.
(V)
Reset OuttRESETWatchdog FeatureWatchdog TimeoutReset Thresh. Accur.
(%)
ICC
(µA)
Package/PinsBudgetary
Price
min@ +25°CmaxSee Notes
MAX6732AFactory 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
2.539SOT/6$1.93 @1k
MAX6733AActive 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
MAX6734AFactory 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
2.539SOT/8$2.10 @1k
MAX6735AActive Low
Push-Pull
SOT/8$3.21 @1k
Quality and Environmental Data
Related Products
  • MAX6715:Dual/Triple Ultra-Low-Voltage SOT23 µP Supervisory Circuits
  • MAX6351:Dual/Triple-Voltage µP Supervisory Circuits
Ordering Information
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX6731AUTLD1+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTLD2+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTLD3+TActiveSOT,;6 pin;9 mm²-40°C to +85°CLead Free
MAX6731AUTLD4+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTLD5+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTLD6+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTMD1+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTMD2+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTMD3+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTMD4+TActiveSOT;-40°C to +85°CSee data sheet
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX6731AUTMD5+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTMD6+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTRD1+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTRD2+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTRD3+ActiveSOT,;6 pin;9 mm²-40°C to +85°CLead Free
MAX6731AUTRD3+TActiveSOT,;6 pin;9 mm²-40°C to +85°CLead Free
MAX6731AUTRD4+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTRD5+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTRD6+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTSD1+TActiveSOT;-40°C to +85°CSee data sheet
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX6731AUTSD2+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTSD3+ActiveSOT,;6 pin;9 mm²-40°C to +85°CLead Free
MAX6731AUTSD3+TActiveSOT,;6 pin;9 mm²-40°C to +85°CLead Free
MAX6731AUTSD3/GG8ActiveSOT,;6 pin;9 mm²-40°C to +85°CNo
MAX6731AUTSD4+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTSD5+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTSD6+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTTD1+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTTD2+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTTD3+ActiveSOT,;6 pin;9 mm²-40°C to +85°CLead Free
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX6731AUTTD3+TActiveSOT,;6 pin;9 mm²-40°C to +85°CLead Free
MAX6731AUTTD4+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTTD5+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTTD6+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTVD1+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTVD2+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTVD3+ActiveSOT,;6 pin;9 mm²-40°C to +85°CLead Free
MAX6731AUTVD3+TActiveSOT,;6 pin;9 mm²-40°C to +85°CLead Free
MAX6731AUTVD4+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTVD5+TActiveSOT;-40°C to +85°CSee data sheet
Part NumberStatusRecommended ReplacementPackageTempRoHS
MAX6731AUTVD6+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTWD1+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTWD2+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTWD3+TActiveSOT,;6 pin;9 mm²-40°C to +85°CLead Free
MAX6731AUTWD4+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTWD5+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTWD6+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTYD1+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTYD2+TActiveSOT;-40°C to +85°CSee data sheet
MAX6731AUTYD3+TActiveSOT,;6 pin;9 mm²-40°C to +85°CLead Free
MAX6730A-MAX6735A.pdf MAX6735A
MAX6731A.pdf MAX6731A
MAX6730A-MAX6735A.pdf MAX6733A