Low-Voltage Manual Reset & Watchdog
Supervisory Circuits in 4-Lead SC70
Preliminary Technical Data
ADM8611/ADM8616/ADM8617/ADM8618
FEATURES
FUNCTIONAL BLOCK DIAGRAMS
Precision 1.8V to 5V Power Supply Monitoring
9 Reset Threshold Options:
1.58V to 4.63V
V
CC
140ms (Min) Reset Timeout
Manual Reset Input (ADM8611)
Watchdog Timer (ADM8616–ADM8618)
Reset Output Stages
ADM8616
V
CC
RESET
RESET
GENERATOR
V
REF
Push-Pull Active-Low
Open-Drain Active-Low
Push-Pull Active-High
WATCHDOG
DETECTOR
Low Power Consumption (3µA)
Guaranteed Reset Output valid to VCC=1V
Power Supply Glitch Immunity
Specified Over -40°C to +85°C Temperature Range
4-Lead SC70 Package
GND
WDI
APPLICATIONS
Microprocessor Systems
Computers
Figure 1.
Controllers
Intelligent Instruments
Portable Equipment
GENERAL DESCRIPTION
Each part is available in a choice of the following 9 reset
threshold options: 1.58V, 1.67V, 2.19V, 2.32V, 2.63V, 2.93V,
3.08V, 4.38V and 4.63V. The reset timeout periods are 20ms
(min) and 140ms (min) for the ADM8611 and ADM8616–
ADM8618, respectively. The watchdog timeout period is 1.6s
(typ). The parts differ in terms of reset output configuration, as
indicated in table 1.
The ADM8611/ADM8616/ADM8617/ADM8618 are
supervisory circuits which monitor power supply voltage levels
and code execution integrity in microprocessor-based systems.
A power-on-reset signal is generated when the supply voltage
rises to a preset threshold level. The ADM8611’s debounced
manual reset input can be used to initiate a reset by means of an
external push-button or logic signal. The ADM8616–ADM8618
have an on-chip watchdog timer which can reset the
microprocessor if it fails to strobe within a preset timeout
period.
The ADM8611/ADM8616/ADM8617/ADM8618 are available
in 4-lead SC70 packages and typically consume only 3µA,
making them suitable for use in low power portable
applications.
Table 1. Selection Table
Output Stage
Part No.
Manual Reset
Watchdog
RESET
RESET
ADM8611
ADM8616
ADM8617
ADM8618
Yes
-
Push-Pull
Push-Pull
Open-Drain
-
-
-
Yes
Yes
Yes
Push-Pull
Rev. PrB
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