Microprocessor Supervisory
Circuit in 4-Lead SOT-143 with DSP
ADM811/ADM812
Data Sheet
FEATURES
FUNCTIONAL BLOCK DIAGRAM
Superior upgrade for MAX811/MAX812
Specified over temperature
Low power consumption: 5 µA typical
Precision voltage monitor: 2.5 V, 3 V, 3.3 V, 5 V options
Reset assertion down to 1 VCC
ADM811/ADM812
V
CC
RESET
GENERATOR
RESET/RESET
GND
V
REF
MR
DEBOUNCE
Power-on reset: 140 ms minimum
RESET
Logic low
output (ADM811)
Figure 1.
Logic high RESET output (ADM812)
Built-in manual reset
APPLICATIONS
Microprocessor systems
Controllers
Intelligent instruments
Automotive systems
Safety systems
Portable instruments
GENERAL DESCRIPTION
The ADM811/ADM812 are reliable voltage monitoring devices
suitable for use in most voltage monitoring applications. The
ADM811/ADM812 are designed to monitor six different
voltages, each allowing a 5% or 10% degradation of standard
PSU voltages before a reset occurs. These voltages have been
selected for the effective monitoring of 2.5 V, 3 V, 3.3 V, and 5 V
supply voltage levels.
V
V
CC
CC
ADM811
MICROPROCESSOR
SYSTEM
MR
RESET
GND
RESET
100kΩ
GND
Included in this circuit is a debounced manual reset input.
Reset can be activated using an electrical switch (or an input
from another digital device) or by a degradation of the supply
voltage. The manual reset function is very useful, especially if
the circuit in which the ADM811/ADM812 are operating enters
into a state that can only be detected by the user. Allowing the
user to reset a system manually can reduce the damage or
danger that could otherwise be caused by an out-of-control
or locked system.
Figure 2. Typical ADM811 Operating Circuit
Rev. G
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