AME8510 Datasheet, PDF (10/13 Pages) Analog Microelectronics – Micropower uP Watch Dog Timer

AME, Inc.
AME8510 / 8520 / 8530
n Detailed Description(contd.)
Watchdog Input Current
The watchdog input pin (WDI) typically sources/sinks
8µA when driven high or low. So from a power dissipa-
tion point of view the duty cycle of the waveform at WDI
is unimportant. When the WDI pin is floating or tri-stated
the power supply current falls to less than 3.0µA.
Glitch Rejection
The AME8510/8520/8530 family will reject negative go-
ing transients on the V_DD line to some extent. The smaller
the duration of the transient the larger its amplitude may
be without triggering a reset. The “Glitch Rejection” chart
in the graphs section of this datasheet shows the rela-
tion between glitch amplitude and allowable glitch dura-
tion to avoid unintended resets.
Accurate Output State at Low V_DD
With V_DD voltage on the order of the MOS transistor
threshold (<1.0V) the outputs of the AME8510/8520/8530
may become undefined. For parts with active low output
(RESETB) a resistor placed between RESETB and GND
on the order of 100KΩ will ensure that the RESETB out-
put stays low when V is lower than the threshold volt-
DD
age of the part. In a like manner a resistor on the order of
100KΩ when placed between RESET and V_DD will en-
sure parts with active high output (RESET) will remain
high when V_DD is lower than the threshold voltage of the
part.
Micropower µP Watch Dog Timer
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