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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

Product Details

Key Features

Parametric specs for Supervisors (3 Monitored Voltages)
Reset Thresh. (V) 0 to 1.2
1.2 to 1.8
1.8 to 2.5
2.5 to 3.3
3.3 to 5.5
Reset Thresh. Accur. (%) (@ +25°C) 2.5
Reset Out Active Low
Push-Pull
Interface Factory Fixed
R/C Adjustable
tRESET (min) 1ms to 15ms
15ms to 85ms
85ms to 300ms
>1s
Watchdog Feature Extended Setup Period
Input (WDI)
Input/Output (WDI/WDO)
Watchdog Timeout 1s to 2s
>2s
Supervisor Features Adjustable Reset Input
Manual Reset
ICC (µA) (max) 39
Package/Pins SOT23/8
Budgetary
Price (See Notes)
3.58
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Simplified Block Diagram

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Parameters

Parametric specs for Supervisors (3 Monitored Voltages)
Reset Thresh. (V) 0 to 1.2
1.2 to 1.8
1.8 to 2.5
2.5 to 3.3
3.3 to 5.5
Reset Thresh. Accur. (%) (@ +25°C) 2.5
Reset Out Active Low
Push-Pull
Interface Factory Fixed
R/C Adjustable
tRESET (min) 1ms to 15ms
15ms to 85ms
85ms to 300ms
>1s
Watchdog Feature Extended Setup Period
Input (WDI)
Input/Output (WDI/WDO)
Watchdog Timeout 1s to 2s
>2s
Supervisor Features Adjustable Reset Input
Manual Reset
ICC (µA) (max) 39
Package/Pins SOT23/8
Budgetary
Price (See Notes)
3.58

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

Applications/Uses

  • Computers/Servers
  • Industrial Equipment
  • Multivoltage Systems
  • Portable Battery-Powered Equipment
  • Printers/Fax Machines
  • Set-Top Boxes
  • Telecom/Networking Equipment

Description

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.

Simplified Block Diagram

MAX6730A, MAX6731A, MAX6732A, MAX6733A, MAX6734A, MAX6735A: Typical Operating Circuit MAX6730A, MAX6731A, MAX6732A, MAX6733A, MAX6734A, MAX6735A: Typical Operating Circuit Zoom icon

Technical Docs

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 .