The MAX16998AAUA/V+ is a high voltage watchdog timer with adjustable timeout delay in 8 pin μMAX package. It is a microprocessor (μP) supervisory circuit for high input voltage and low quiescent current applications. This device detects downstream circuit failures and provides switchover to redundant circuitry. The MAX16998A 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 generates two output signals complementary RESET and complementary ENABLE. Complementary 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, complementary RESET remains low for the reset timeout period, tRESET and then goes high.
Wide 5V to 40V input voltage range
Automotive temperature range from -40°C to 125°C
Automotive AEC-Q100 grade 1 qualified
18μA quiescent current (typical at +125°C)
Capacitor adjustable timeout period for watchdog and reset
External voltage monitoring and power-on/power-off reset functionality
TTL and CMOS compatible open-drain outputs and car battery compatible EN input
Watch dog window size is 100%, WDI narrow pulse immunity
Maximum open-drain enable output voltage is 28V and maximum open-drain reset output voltage of 18V
Windowed watchdog timer option and reset timeout period of 5ms