Low Voltage Supervisory Circuits
with Watchdog in 4-Lead SC70
ADM8616/ADM8617
FEATURES
FUNCTIONAL BLOCK DIAGRAM
Precision 1.8 V to 5 V power supply monitoring
ADM8616
RESET
9
threshold options
1.58 V to 4.63 V
RESET
V
CC
V
CC
RESET
GENERATOR
4
timeout options
RESET
V
REF
1 ms, 20 ms, 140 ms, 1120 ms
3 watchdog timeout options
6.3 ms, 102 ms, 1.6 sec
WATCHDOG
DETECTOR
RESET
output stages
Push-pull active-low (ADM8616)
Open-drain active-low (ADM8617)
Low power consumption (5 μA)
Guaranteed reset output valid to VCC = 1 V
Power supply glitch immunity
GND
WDI
Figure 1.
Specified over −40°C to +85°C temperature range
4-lead SC70 package
APPLICATIONS
Microprocessor systems
Computers
Controllers
Intelligent instruments
Portable equipment
GENERAL DESCRIPTION
The ADM8616/ADM8617 are supervisory circuits that 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 ADM8616/ADM8617 have an on-chip watchdog
timer that can reset the microprocessor if it fails to strobe
within a preset timeout period.
The parts differ in terms of reset output configuration. The
ADM8616 is active-low with a push-pull output, while the
ADM8617 is active-low with an open-drain output.
The ADM8616/ADM8617 are available in 4-lead SC70 packages
and typically consume only 5 μA, making them suitable for use
in low power, portable applications.
Each part is available in the following nine reset threshold
options: 1.58 V, 1.67 V, 2.19 V, 2.32 V, 2.63 V, 2.93 V, 3.08 V,
4.38 V, and 4.63 V. There are four reset timeout options: 1 ms,
20 ms, 140 ms, and 1120 ms. There are also three possible
watchdog timeouts available: 6.3 ms, 102 ms, and 1.6 sec.
Rev. B
Information furnished by Analog Devices is believed to be accurate and reliable. However, no
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other
rights of third parties that may result from its use. Specifications subject to change without notice. No
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.
Trademarks and registeredtrademarks arethe property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.461.3113
www.analog.com
©2007 Analog Devices, Inc. All rights reserved.