ADM811/ADM812
INTERFACING TO OTHER DEVICES
OUTPUT
The ADM811/ADM812 are designed to integrate with as many
devices as possible. One feature of the ADM811/ADM812 is the
reset output, which is directly proportional to V
CC
(this is guar-
anteed only while V
CC
is greater than 1 V). This enables the part
to be used with both 3 V and 5 V, or any nominal voltage within
the minimum and maximum specifications for V
CC
.
V
CC
V
CC
Data Sheet
ADM811
RESET
GND
BENEFITS OF A VERY ACCURATE RESET
THRESHOLD
Because the ADM811/ADM812 can operate effectively even
when there are large degradations of the supply voltages, the
possibility of a malfunction during a power failure is greatly
reduced. Another advantage of the ADM811/ADM812 is its
very accurate internal voltage reference circuit. Combined,
these benefits produce an exceptionally reliable microprocessor
supervisory circuit.
Figure 11. Ensuring a Valid RESET Output Down to V
CC
= 0 V
ENSURING A VALID RESET/RESET
OUTPUT DOWN TO V
CC
= 0 V
When V
CC
falls below 0.8 V, the RESET/RESET of the ADM811/
ADM812 no longer sinks current. Therefore, a high impedance
CMOS logic input connected to RESET/RESET can drift to
undetermined logic levels. To eliminate this problem, a 100 kΩ
resistor should be connected from RESET/RESET to ground.
Rev. G | Page 8 of 12
00092-011
AD [ ANALOG DEVICES ]
