MAX16997AAUA+

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. 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, RESET and ENABLE. 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, RESET remains low for the reset timeout period, tRESET, and then goes high. The MAX16997A generates one output signal (ENABLE) based on the voltage level at EN and the signal at WDI. The MAX16997A does not have a 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 pre - set 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 (Pb) - free μMAX packages and are fully specified over the - 40°C to + 125°C automotive temperature range.

Applications

• Automotive
• Industrial

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×3mm μMAX Package
• WDI Narrow Pulse Immunity