Supervisory Circuits with Watchdog
and Manual Reset in 5-Lead SOT-23
ADM6316/ADM6317/ADM6318/ADM6319/ADM6320/ADM6321/ADM6322
FEATURES
26 reset threshold options
2.5 V to 5 V in 100 mV increments
4 reset timeout options
1 ms, 20 ms, 140 ms, and 1120 ms (min)
4 watchdog timeout options
6.3 ms, 102 ms, 1600 ms, and 25.6 sec (typ)
Manual reset input
Reset output stages
Push-pull active low
Open-drain active low
Push-pull active high
Low power consumption (5 μA)
Guaranteed reset output valid to V
CC
= 1 V
Power supply glitch immunity
Specified over industrial temperature range
5-lead SOT-23 package
FUNCTIONAL BLOCK DIAGRAM
ADM6316/ADM6320
V
CC
V
CC
V
REF
RESET
GENERATOR
RESET
MR
DEBOUNCE
WATCHDOG
DETECTOR
04533-001
GND
WDI
Figure 1.
APPLICATIONS
Microprocessor systems
Computers
Controllers
Intelligent instruments
Portable equipment
GENERAL DESCRIPTION
TheADM6316/ADM6317/ADM6318/ADM6319/ADM6320/
ADM6321/ADM6322 are supervisory circuits that monitor
power supply voltage levels and code execution integrity in
microprocessor-based systems. As well as providing power-on
reset signals, an on-chip watchdog timer can reset the micro-
processor if it fails to strobe within a preset timeout period. A
reset signal can also be asserted by an external push-button
through a manual reset input. The seven parts feature different
combinations of watchdog input, manual reset input, and
output stage configuration, as shown in Table 1.
Table 1. Selection Table
Output Stage
Part No.
ADM6316
ADM6317
ADM6318
ADM6319
ADM6320
ADM6321
ADM6322
Watchdog
Yes
Yes
Yes
No
Yes
Yes
No
Manual Reset
Yes
Yes
No
Yes
Yes
No
Yes
RESET
Push-Pull
No
Push-Pull
Push-Pull
Open-Drain
Open-Drain
Open-Drain
RESET
No
Push-Pull
Push-Pull
Push-Pull
No
Push-Pull
Push-Pull
Each part is available in a choice of 26 reset threshold options
ranging from 2.5 V to 5 V in 100 mV increments. There are also
four reset timeout options of 1 ms, 20 ms, 140 ms, and 1120 ms
(minimum) and four watchdog timeout options of 6.3 ms, 102 ms,
1600 ms, and 25.6 sec (typical).
The ADM6316/ADM6317/ADM6318/ADM6319/ADM6320/
ADM6321/ADM6322 are available in 5-lead SOT-23 packages
and typically consume only 3 μA, making them suitable for use
in low power portable applications.
Rev. A
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.
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Tel: 781.329.4700
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Fax: 781.461.3113
©2006 Analog Devices, Inc. All rights reserved.
ADM6316/ADM6317/ADM6318/ADM6319/ADM6320/ADM6321/ADM6322
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications....................................................................................... 1
Functional Block Diagram .............................................................. 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Absolute Maximum Ratings............................................................ 5
ESD Caution.................................................................................. 5
Pin Configurations and Function Descriptions ........................... 6
Typical Performance Characteristics ............................................. 7
Circuit Description........................................................................... 9
Reset Output ................................................................................. 9
Open-Drain RESET Output ........................................................9
Manual Reset Input .......................................................................9
Watchdog Input .............................................................................9
Application Information................................................................ 10
Watchdog Input Current ........................................................... 10
Negative-Going V
CC
Transients ................................................ 10
Ensuring Reset Valid to V
CC
= 0 V ........................................... 10
Watchdog Software Considerations......................................... 10
Options ............................................................................................ 11
Outline Dimensions ....................................................................... 13
Ordering Guide .......................................................................... 13
REVISION HISTORY
5/06—Rev. 0 to Rev. A
Updated Format..................................................................Universal
Changes to Functional Block Diagram.......................................... 1
Changes to Table 8.......................................................................... 12
Changes to Figure 22...................................................................... 13
Changes to Ordering Guide .......................................................... 13
10/04—Revision 0: Initial Version
Rev. A | Page 2 of 16
ADM6316/ADM6317/ADM6318/ADM6319/ADM6320/ADM6321/ADM6322
SPECIFICATIONS
V
CC
= full operating range, T
A
= T
MIN
to T
MAX
, unless otherwise noted.
Table 2.
Parameter
SUPPLY
V
CC
Operating Voltage Range
Supply Current
RESET THRESHOLD VOLTAGE
RESET THRESHOLD TEMPERATURE
COEFFICIENT
RESET THRESHOLD HYSTERESIS
RESET TIMEOUT PERIOD
ADM63xxA
ADM63xxB
ADM63xxC
ADM63xxD
V
CC
TO RESET DELAY
PUSH-PULL OUTPUT (ADM6316,
ADM6317, ADM6318, ADM6319,
ADM6321, ADM6322)
RESET Output Voltage
Min
1
10
5
V
TH
V
TH
40
3
1
20
140
1120
1.4
28
200
1600
40
2
40
280
2240
Typ
Max
5.5
20
12
V
TH
+ 1.5%
V
TH
+ 2.5%
Unit
V
μA
μA
V
V
ppm/°C
mV
ms
ms
ms
ms
μs
Test
Conditions/Comments
V
TH
− 1.5%
V
TH
− 2.5%
V
CC
= 5.5 V
V
CC
= 3.6 V
T
A
= 25°C
T
A
= −40°C to +85°C
V
CC
falling at 1 mV/μs
0.3
0.3
0.3
0.4
0.8 × V
CC
V
CC
− 1.5
V
V
V
V
V
V
ns
V
V
V
V
V
RESET Rise Time
5
RESET Output Voltage
0.8 × V
CC
0.8 × V
CC
V
CC
– 1.5
OPEN-DRAIN OUTPUT (ADM6320,
ADM6321, ADM6322)
RESET Output Voltage
25
0.3
0.4
V
CC
≥
1.0 V, I
SINK
= 50 μA
V
CC
≥
1.2 V, I
SINK
= 100 μA
V
CC
≥ 2.7 V, I
SINK
= 1.2 mA
V
CC
≥ 4.5 V, I
SINK
= 3.2 mA
V
CC
≥ 2.7 V, I
SOURCE
= 500 μA
V
CC
≥ 4.5 V, I
SOURCE
= 800 μA
From 10% to 90% V
CC
, C
L
=
5 pF, V
CC
= 3.3 V
V
CC
≥ 2.7 V, I
SINK
= 1.2 mA
V
CC
≥ 4.5 V, I
SINK
= 3.2 mA
V
CC
≥ 1.8 V, I
SOURCE
= 150 μA
V
CC
≥ 2.7 V, I
SOURCE
= 500 μA
V
CC
≥ 4.5 V, I
SOURCE
= 800 μA
0.3
0.3
0.3
0.4
1
V
V
V
V
μA
V
CC
≥ 1.0 V, I
SINK
= 50 μA
V
CC
≥ 1.2 V, I
SINK
= 100 μA
V
CC
≥ 2.7 V, I
SINK
= 1.2 mA
V
CC
≥ 4.5 V, I
SINK
= 3.2 mA
Open-Drain Reset Output
Leakage Current
Rev. A | Page 3 of 16
ADM6316/ADM6317/ADM6318/ADM6319/ADM6320/ADM6321/ADM6322
Parameter
WATCHDOG INPUT (ADM6316,
ADM6317, ADM6318,
ADM6320, ADM6321)
Watchdog Timeout Period
Min
Typ
Max
Unit
Test
Conditions/Comments
WDI Pulse Width
WDI Input Threshold
WDI Input Current
MANUAL RESET INPUT (ADM6316,
ADM6317, ADM6319,
ADM6320, ADM6322)
MR Input Threshold
MR Input Pulse Width
MR Glitch Rejection
MR Pull-Up Resistance
MR to Reset Delay
4.3
71
1.12
17.9
50
0.3 × V
CC
−20
6.3
102
1.6
25.6
9.3
153
2.4
38.4
0.7 × V
CC
160
120
−15
ms
ms
s
s
ns
V
μA
μA
ADM63xxxW
ADM63xxxX
ADM63xxxY
ADM63xxxZ
V
IL
= 0.3 × V
CC
, V
IH
= 0.7 × V
CC
V
WDI
= V
CC
, time average
V
WDI
= 0, time average
0.8
0.3 × V
CC
1
35
100
52
230
2.0
0.7 × V
CC
75
V
V
μs
ns
kΩ
ns
V
TH
> 4.0 V
V
TH
< 4.0 V
V
CC
= 5 V
Rev. A | Page 4 of 16
ADM6316/ADM6317/ADM6318/ADM6319/ADM6320/ADM6321/ADM6322
ABSOLUTE MAXIMUM RATINGS
T
A
= 25°C, unless otherwise noted.
Table 3.
Parameter
V
CC
RESET (ADM6320, ADM6321,
ADM6322)
All Other Pins
Output Current (RESET, RESET)
Operating Temperature Range
Storage Temperature Range
θ
JA
Thermal Impedance, SOT-23
Lead Temperature
Soldering (10 sec)
Vapor Phase (60 sec)
Infrared (15 sec)
Rating
−0.3 V to +6 V
−0.3 V to +6 V
−0.3 V to (V
CC
+ 0.3 V)
20 mA
−40°C to +85°C
−65°C to +125°C
270°C/W
300°C
215°C
220°C
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
ESD CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on
the human body and test equipment and can discharge without detection. Although this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance
degradation or loss of functionality.
Rev. A | Page 5 of 16
