Top

High-Voltage Watchdog Timers with Adjustable Timeout Delay

Highest Input Voltage Watchdog Consumes Only 18µA Supply Current

Product Details

Key Features

Parametric specs for Watchdog Timers
Watchdog Feature Input (WDI)
Watchdog Timeout Adjustable
Watchdog Output Open-Drain
ICC (µA) (max) 60
Package/Pins UMAX/8
Oper. Temp. (°C) -40 to +125
Budgetary
Price (See Notes)
1.15
View Less

Simplified Block Diagram

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 .

Parameters

Parametric specs for Watchdog Timers
Watchdog Feature Input (WDI)
Watchdog Timeout Adjustable
Watchdog Output Open-Drain
ICC (µA) (max) 60
Package/Pins UMAX/8
Oper. Temp. (°C) -40 to +125
Budgetary
Price (See Notes)
1.15

Key Features

  • Wide 5V to 40V Input Voltage Range
  • 18µA Quiescent Current (Typical at +125°C)
  • Capacitor-Adjustable Timeout Period for Watchdog and Reset
  • Windowed Watchdog Timer Options (MAX16998B/D)
  • External Voltage Monitoring (RESETIN for the MAX16998A/B/D and EN for the MAX16997A)
  • Car Battery-Compatible EN Input
  • TTL- and CMOS-Compatible Open-Drain Outputs
  • 18V Maximum Open-Drain Reset Output Voltage
  • 28V Maximum Open-Drain Enable Output Voltage
  • Power-On/Power-Off Reset Functionality (MAX16998A/B/D Only)
  • AEC-Q100 Qualified
  • -40°C to +125°C Operating Temperature Range
  • Small (3mm x 3mm) µMAX Package
  • WDI Narrow Pulse Immunity

Applications/Uses

  • Automotive
  • Industrial

Description

The MAX16997/MAX16998 are microprocessor (µP) supervisory circuits for high-input-voltage and low-quiescent-current applications. These devices detect downstream circuit failures and provide switchover to redundant circuitry. See the Selector Guide in the full data sheet for the different versions of this product family.

The MAX16997/MAX16998 family has four independent inputs for reset and watchdog functions. SWT and SRT inputs independently set the timeout periods of watchdog and reset timers through external capacitors. RESETIN/EN monitor voltages at respective inputs. A resistive voltage-divider sets the reset threshold.

The MAX16998A/B/D generate two output signals, active-low RESET and active-low ENABLE. Active-low RESET asserts whenever RESETIN drops below its threshold voltage or when the watchdog timer detects a timing fault at WDI. Once asserted, and after all reset conditions are removed, active-low RESET remains low for the reset timeout period, tRESET, and then goes high. The MAX16997A generates one output signal (active-low ENABLE) based on the voltage level at EN and the signal at WDI.<.p>

The MAX16997A does not have a active-low RESET output. The watchdog is disabled if the voltage at EN is below its threshold. The MAX16997A watchdog timer starts timing when the voltage at EN becomes higher than the preset threshold voltage level. Each time EN rises above the preset threshold voltage, the initial watchdog timeout period is 8 times the normal watchdog timeout period (tWP).

The MAX16997/MAX16998 are available in 8-pin lead-free µMAX® packages and are fully specified over the -40°C to +125°C automotive temperature range.

Simplified Block Diagram

MAX16997, MAX16998: Functional Diagram MAX16997, MAX16998: Functional Diagram 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 .