Analog Devices ADM8699, ADM8698 Datasheet
Microprocessor
*
ADM8699 ONLY
+5V
V
CC
WDI
*
GND
ADM8698/
ADM8699
RESET
µP POWER
µP SYSTEM
I/O LINE
µP RESET
a
FEATURES
Superior Up
Guaranteed
Low 70 mA Supply Current
Precision 4.65 V Voltage Monitor
Power OK/Reset Time Delay
Watchdog Timer
Minimum Component Count
Performance Specified over Temperature
APPLICATIONS
Microprocessor Systems
Computers
Controllers
Intelligent Instruments
Automotive Systems
Critical mP Power Monitoring
GENERAL DESCRIPTION
The ADM8698/ADM8699 supervisory circuits provide power
supply monitoring and watchdog timing for microprocessor
systems.
The ADM8698 monitors the 5 V V
ates a
RESET pulse during power up, power down and during
low voltage “Brown Out” conditions. The
guaranteed to be functional (logic low) with V
The ADM8699 features an identical monitoring circuit as in the
ADM8698, plus an additional watchdog timer input to monitor
microprocessor activity. The
watchdog input is not toggled within the 1 second watchdog
timeout period.
Both parts are available in 8-pin plastic DIP/SOIC and 16-lead
SOIC packages. The 16-lead SOIC contains additional outputs
RESET (without inversion) and Watchdog Output WDO
(ADM8699 only).
grade for ADM698/ADM699, MAX698/MAX699
RESET Assertion with VCC = 1 V
power supply and gener-
CC
RESET output is
as low as 1 V.
CC
RESET output is forced low if the
V
CC
WATCHDOG
INPUT
WDI*
Supervisory Circuits
ADM8698/ADM8699
FUNCTIONAL BLOCK DIAGRAM
ADM8698/
ADM8699
RESET
GENERATOR
4.65V
WATCHDOG
TRANSITION DETECTOR
(1 sec)
WDI (ADM8699 ONLY)
*
RESET (SOIC ONLY)
WDO (ADM8699 SOIC ONLY)
TYPICAL APPLICATION CIRCUIT
RESET*
RESET
WATCHDOG
OUTPUT WDO*
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use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
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Tel: 617/329-4700 World Wide Web Site: http://www.analog.com
Fax: 617/326-8703 © Analog Devices, Inc., 1997
ADM8698/ADM8699–SPECIFICATIONS
Parameter Min Typ Max Units Test Conditions/Comments
(VCC = +5 V 6 10%, TA = T
MIN
to T
unless otherwise noted)
MAX
VCC Operating Voltage Range 3.0 5.5 V
Supply Current 70 100 µA
Power-Down Reset Assertion 4.5 4.65 4.75 V
Power-Up Reset Deassertion
Reset Threshold Hysteresis 40 mV
Reset Active Time 140 200 280 ms
Watchdog Timeout Period (ADM8699) 1.0 1.6 2.25 s
Minimum WDI Input Pulse Width 50 ns VIL = 0.4, VIH = 0.8 (VCC)
RESET Output Voltage 0.4 V I
RESET Output Voltage (VCC = 1 V) 12 200 mV I
3.5 V I
RESET and
WDO Output Voltage 0.4 V I
3.5 V I
= 3.2 mA, VCC = 4.4 V
SINK
= 100 µA, VCC = 1.0 V
SINK
= 500 µA, VCC = 5 V
SOURCE
= 3.2 mA, VCC = 5 V
SINK
= 1 µA, VCC = 4.4 V
SOURCE
RESET Output Short Circuit Current 45 mA Output Sink Current
WDI Input Threshold (ADM8699)
Logic Low 0.8 V
Logic High 3.5 V
WDI Input Current +1 +10 µA WDI = V
CC
–10 –1 µA WDI = 0 V
Specifications subject to change without notice.
ABSOLUTE MAXIMUM RATINGS*
(TA = +25°C unless otherwise noted)
VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .–0.3 V to +6 V
All Other Inputs . . . . . . . . . . . . . . . . . . . –0.3 V to V
+ 0.3 V
CC
Power Dissipation 8-Pin DIP . . . . . . . . . . . . . . . . . . . .500 mW
θ
, Thermal Impedance . . . . . . . . . . . . . . . . . . . . +120°C/W
JA
Power Dissipation 16-Pin SOIC . . . . . . . . . . . . . . . . .375 mW
θ
, Thermal Impedance . . . . . . . . . . . . . . . . . . . . +110°C/W
JA
Power Dissipation 8-Pin SOIC . . . . . . . . . . . . . . . . . .500 mW
θ
, Thermal Impedance . . . . . . . . . . . . . . . . . . . . +125°C/W
JA
Operating Temperature Range
Industrial (A Version) . . . . . . . . . . . . . . . . .–40°C to +85°C
Storage Temperature Range . . . . . . . . . . . . .–65°C to +150°C
Model Range Options*
ADM8698AN –40°C to +85°C N-8
ADM8698ARW –40°C to +85°C R-16
ADM8698ARN –40°C to +85°C R-8
ADM8699AN –40°C to +85°C N-8
ADM8699ARW –40°C to +85°C R-16
ADM8699ARN –40°C to +85°C R-8
*N = Plastic DIP; R = Small Outline.
ORDERING GUIDE
Temperature Package
Lead Temperature (Soldering, 10 secs) . . . . . . . . . . . . +300°C
Vapor Phase (60 secs) . . . . . . . . . . . . . . . . . . . . . . . +215°C
Infrared (15 secs) . . . . . . . . . . . . . . . . . . . . . . . . . . . +220°C
ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .>4 kV
*Stresses above those listed under Absolute Maximum Ratings may cause perma-
nent damage to the device. This is a stress rating only; functional operation of the
device at these or any other conditions above those listed in the operational sections
of this specification is not implied. Exposure to absolute maximum ratings for
extended periods of time may affect device reliability.
–2–
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