Supervisory Circuits with Watchdog
and Manual Reset in 5-Lead SOT-23
Data Sheet
FEATURES
27 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 (minimum)
4 watchdog timeout options
6.3 ms, 102 ms, 1.6 sec, and 25.6 sec (typical)
Manual reset input
Multiple reset output options
Low power consumption
Specified over wide temperature range (−40°C to +125°C)
Qualified for automotive applications
5-lead SOT-23 package
ADM8316/ADM8318/ADM8319/ADM8320/ADM8321/ADM8322
FUNCTIONAL BLOCK DIAGRAMS
ADM8316
V
CC
V
CC
V
REF
RESET
GENERATOR
RESET
MR
DEBOUNCE
WATCHDOG
DETECTOR
11779-001
GND
WDI
Figure 1.
ADM8316
APPLICATIONS
Automotive infotainment
Microprocessor systems
Computers
Controllers
Intelligent instruments
Portable equipment
V
CC
ADM8320
V
REF
RESET
GENERATOR
RESET
MR
DEBOUNCE
WATCHDOG
DETECTOR
11779-002
GND
WDI
Figure 2.
ADM8320
GENERAL DESCRIPTION
The
ADM8316/ADM8318/ADM8319/ADM8320/ADM8321/
ADM8322
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 microprocessor if it fails to strobe
within a preset timeout period. A reset signal can also be asserted
by an external push-button switch through a manual reset input.
The six devices feature different combinations of watchdog
input, manual reset input, and output stage configuration,
as shown in Table 6.
Each device is available in a choice of 27 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,
1.6 sec, and 25.6 sec (typical).
The
ADM8316/ADM8318/ADM8319/ADM8320/ADM8321/
ADM8322
are available in 5-lead SOT-23 packages and typically
consume only 10 µA, making them suitable for use in low
power, portable applications.
Rev. B
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ADM8316/ADM8318/ADM8319/ADM8320/ADM8321/ADM8322
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications ....................................................................................... 1
Functional Block Diagrams ............................................................. 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
Theory of Operation ...................................................................... 10
Circuit Description..................................................................... 10
Push-Pull Reset Output ............................................................. 10
Data Sheet
Open-Drain RESET Output ..................................................... 10
Manual Reset Input .................................................................... 10
Watchdog Input .......................................................................... 10
Applications Information .............................................................. 11
Watchdog Input Current ........................................................... 11
Negative Going V
CC
Transients................................................. 11
Ensuring Reset Valid to V
CC
= 0 V ........................................... 11
Watchdog Software Considerations ......................................... 11
Options ............................................................................................ 12
Outline Dimensions ....................................................................... 14
Ordering Guide .......................................................................... 14
Automotive Products ................................................................. 15
REVISION HISTORY
9/2016—Rev. A to Rev. B
Change to Features Section ............................................................. 1
Changes to Table 9 .......................................................................... 12
Changes to Table 10 ........................................................................ 13
Changes to Ordering Guide .......................................................... 14
9/2015—Rev. 0 to Rev. A
Changes to Table 10 ........................................................................ 13
10/13—Revision 0: Initial Version
Rev. B | Page 2 of 15
Data Sheet
SPECIFICATIONS
ADM8316/ADM8318/ADM8319/ADM8320/ADM8321/ADM8322
V
CC
= (V
TH
+ 1.5%) to 5.5 V, T
A
= −40°C to +125°C, unless otherwise noted. Typical values are at T
A
= 25°C.
Table 1.
Parameter
SUPPLY
V
CC
Operating Voltage Range
1
V
CC
that Guarantees Valid Output
Supply Current (WDI Floating)
RESET THRESHOLD VOLTAGE
2
RESET THRESHOLD TEMPERATURE COEFFICIENT
RESET THRESHOLD HYSTERESIS
RESET TIMEOUT PERIOD
Reset Timeout Option A
Reset Timeout Option B
Reset Timeout Option C
Reset Timeout Option D
V
CC
TO RESET DELAY, t
RD
PUSH-PULL OUTPUT (ADM8316,
ADM8318, ADM8319,
ADM8321, ADM8322)
RESET Output Voltage
Min
0.9
0.9
10
10
V
TH
V
TH
20
2.5 × V
TH
1.4
28
200
1600
90
Typ
Max
5.5
20
18
V
TH
+ 1%
V
TH
+ 1.5%
Unit
V
V
µA
µA
V
V
ppm/°C
mV
ms
ms
ms
ms
µs
Test Conditions/Comments
V
TH
− 1%
V
TH
− 1.5%
V
CC
= 5.5 V
V
CC
= 3.6 V
T
A
= 25°C
T
A
= −40°C to +125°C
See Table 7
1
20
140
1120
1.8
36
260
2080
V
CC
falling at 1 mV/µs
0.2
0.2
0.2
0.3
0.9 × V
CC
0.9 × V
CC
RESET Rise Time
RESET Output Voltage
0.9 × V
CC
0.9 × V
CC
OPEN-DRAIN OUTPUT (ADM8320,
ADM8321, ADM8322)
RESET Output Voltage
50
100
0.2
0.3
V
V
V
V
V
V
ns
V
V
V
V
V
V
V
V
µA
V
CC
≥ 0.9 V, I
SINK
= 25 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
≥ 2.7 V, I
SOURCE
= 500 µA
V
CC
≥ 4.5 V, I
SOURCE
= 800 µA
V
CC
≥ 0.9 V, I
SINK
= 25 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
WATCHDOG INPUT (ADM8316,
ADM8318, ADM8320,
ADM8321)
Watchdog Timeout Period, t
WD
Watchdog Timeout Option W
Watchdog Timeout Option X
Watchdog Timeout Option Y
Watchdog Timeout Option Z
WDI Pulse Width
WDI Input Threshold
WDI Input Current
0.2
0.2
0.2
0.3
1
See Table 8
4.5
72
1.12
18.0
50
0.3 × V
CC
6.3
102
1.6
25.6
8.1
132
2.24
33.2
0.7 × V
CC
100
ms
ms
sec
sec
ns
V
µA
V
IL
= 0.3 × V
CC
, V
IH
= 0.7 × V
CC
35
Rev. B | Page 3 of 15
ADM8316/ADM8318/ADM8319/ADM8320/ADM8321/ADM8322
Parameter
MANUAL RESET INPUT (ADM8316,
ADM8319, ADM8320,
ADM8322)
V
IL
V
IH
MR Input Pulse Width
MR Glitch Rejection
MR Pull-Up Resistance
MR to Reset Delay
1
2
Data Sheet
Unit
Test Conditions/Comments
Min
Typ
Max
0.8
2.0
1
35
100
75
350
125
V
V
µs
ns
kΩ
ns
V
CC
= 5 V
The device switches from undervoltage reset to normal operation when 1.5 V <
V
CC
< 2.5 V.
The device monitors V
CC
through an internal factory trimmed voltage divider that programs the nominal reset threshold. Factory-trimmed reset thresholds are
available in approximately 100 mV increments from 2.5 V to 5 V.
Rev. B | Page 4 of 15
Data Sheet
T
A
= 25°C, unless otherwise noted.
Table 2.
Parameter
V
CC
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)
ADM8316/ADM8318/ADM8319/ADM8320/ADM8321/ADM8322
Stresses at or above those listed under Absolute Maximum
Ratings may cause permanent damage to the product. This is a
stress rating only; functional operation of the product at these
or any other conditions above those indicated in the operational
section of this specification is not implied. Operation beyond
the maximum operating conditions for extended periods may
affect product reliability.
ABSOLUTE MAXIMUM RATINGS
Rating
−0.3 V to +6 V
−0.3 V to (V
CC
+ 0.3 V)
20 mA
−40°C to +125°C
−65°C to +150°C
270°C/W
300°C
215°C
220°C
ESD CAUTION
Rev. B | Page 5 of 15
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