Analog Devices ADM8616 7 pre Datasheet

Low-Voltage Watchdog

Preliminary Technical Data

FEATURES

Precision 1.8V to 5V Power Supply Monitoring
9 Reset Threshold Options:

1.58V to 4.63V
4 Reset Timeout Options:

1ms, 20ms, 140ms, 1120ms
Watchdog Timer
Reset Output Stages

Push-Pull Active-Low (ADM8616)

Open-Drain Active-Low (ADM8617)
Low Power Consumption (3µA)
Guaranteed Reset Output valid to V
Power Supply Glitch Immunity
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 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 ADM8616/ADM8617 have an on-chip
watchdog timer which can reset the microprocessor if it fails to
strobe within a preset timeout period.

CC

=1V

Supervisory Circuits in 4-Lead SC70

ADM8616/ADM8617

FUNCTIONAL BLOCK DIAGRAMS

V

ADM8616

V

CC

V

REF

GND

RESET

GENERATOR

WATCHDOG

DETECTOR

WDI

Figure 1.

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. There are four reset timeout options­1ms, 20ms, 140ms and 1120ms. There are also four possible
watchdog timeouts available- 6.3ms, 102ms, 1.6s and 25s. The
parts differ in terms of reset output configuration, ADM8616 is
active low with a Push- Pull output while ADM8617 is active
low with an Open- Drain Output.

CC

4-5-6

Rev. PrE

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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
registered trademarks are the property of their respective owners.

The ADM8616/ADM8617 are available in 4-lead SC70
packages and typically consume only 3µA, making them
suitable for use in low power portable applications.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] © 2005 Analog Devices, Inc. All rights reserved.

ADM8616/ADM8617 Preliminary Technical Data

ADM8616/ADM8617—SPECIFICATIONS

Table 2. VCC=Full Operating Range, TA=-40oC to 85oC, unless otherwise noted

Parameter Min Typ Max Units Test Conditions/Comments

SUPPLY
VCC Operating Voltage Range 1 5.5 V

Supply Current 10 20 µA VCC=5.5V
5 12 µA VCC=3.6V

RESET THRESHOLD VOLTAGE

ADM861_L
ADM861_M
ADM861_T
ADM861_S
ADM861_R
ADM861_Z
ADM861_Y
ADM861_W

ADM861_V
RESET THRESHOLD TEMPERATURE COEFFICIENT 40 ppm/°C
RESET THRESHOLD HYSTERESIS 3 mV
RESET TIMEOUT PERIOD
ADM861_ _A 1 1.4 2 ms
ADM861_ _B 20 28 40 ms
ADM861_ _C 140 200 280 ms
ADM861_ _D 1120 1600 2240 ms
VCC TO RESET DELAY 40 µs V
PUSH-PULL OUTPUT (ADM8616)

RESET

Output Voltage

0.3 V VCC>=1.2V, I

0.3 V VCC>=2.7V, I

0.4 V VCC>=4.5V, I

0.8x VCC V VCC>=2.7V, I

V

RESET

Rise Time

OPEN-DRAIN OUTPUT (ADM8617)

RESET

Output Voltage

0.3 V VCC>=1.2V, I

0.3 V VCC>=2.7V, I

0.4 V VCC>=4.5V, I

Open-Drain Reset Output Leakage Current 1 µA
WATCHDOG INPUT
Watchdog Timeout Period

ADM861_ _ _W 4.3 6.3 9.3 ms
ADM861_ _ _X 71 102 153 ms
ADM861_ _ _Y 1.12 1.6 2.24 s

ADM861_ _ _Z 17.9 25.6 38.4 s
WDI Pulse Width 50 ns VIL=0.3xVCC, VIH=0.7xVCC,
WDI Input Threshold 0.3xVCC V

0.7xVCC V
WDI Input Current 120 160 µA V

4.50 4.63 4.75 V

4.25 4.38 4.50 V

3.00 3.08 3.15 V

2.85 2.93 3.00 V

2.55 2.63 2.70 V

2.25 2.32 2.38 V

2.12 2.19 2.25 V

1.62 1.67 1.71 V

1.52 1.58 1.62 V

falling at 1mV/µs

CC

0.3 V VCC>=1.0V, I

-1.5 V VCC>=4.5V, I

CC

5 25 ns

0.3 V V

From 10% to 90% V

=3.3V

V

CC

>=1.0V, I

CC

=50µA

SINK

=100µA

SINK

=1.2mA

SINK

=3.2mA

SINK

SOURCE

SOURCE

=50µA

SINK

=100µA

SINK

=1.2mA

SINK

=3.2mA

SINK

=500µA

=800µA

, CL=5pF,

CC

= VCC, time average

WDI

-20 -15 µA V

=0, time average

WDI

Rev. PrE | Page 2 of 10

Preliminary Technical Data ADM8616/ADM8617

ABSOLUTE MAXIMUM RATINGS

Table 3. TA = 25°C unless otherwise noted.

Parameter Rating
VCC -0.3V to +6V
RESET

/RESET

Output Current (RESET,
Operating Temperature Range -40°C to +85°C
Storage Temperature Range -65°C to +150°C

θJA Thermal Impedance, SC70

Lead Temperature
Soldering (10 sec) 300°C
Vapour Phase (60 sec) 215°C
Infrared (15 sec) 220°C

RESET

)

-0.3V to +6V
20mA

146°C/W

Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only and 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.

Rev. PrE | Page 3 of 10