Analog Devices ADM706 8 a Datasheet

+3 V, Voltage Monitoring

WATCHDOG
TRANSITION

DETECTOR

WATCHDOG

TIMER

1.25V

V

REF

*

WATCHDOG

INPUT (WDI)

POWER FAIL

INPUT (PFI)

POWER FAIL
OUTPUT (PFO)

WATCHDOG
OUTPUT(WDO)

RESET,
(P = RESET)

*VOLTAGE REFERENCE = 2.63V (P/R), 2.93V (S), 3.08V (T)

ADM706

RESET &

WATCHDOG

TIMEBASE

RESET

GENERATOR

MR

V

CC

70mA

V

CC

1.25V

V

REF

*

POWER FAIL

INPUT (PFI)

POWER FAIL
OUTPUT (PFO)

RESET

*VOLTAGE REFERENCE = 2.63V (R), 2.93V (S), 3.08V (T)

ADM708

RESET

GENERATOR

MR

V

CC

70mA

V

CC

RESET

a

FEATURES
Precision Supply-Voltage Monitor

+2.63 V (ADM706P/R, ADM708R)
+2.93 V (ADM706S, ADM708S)

+3.08 V (ADM706T, ADM708T)
100 ␮A Quiescent Current
200 ms Reset Pulsewidth
Debounced Manual Reset Input (MR)
Independent Watchdog Timer—1.6 sec Timeout

(ADM706x)
Reset Output

Active High (ADM706P)

Active Low (ADM706R/S/T)

Both Active High and Active Low (ADM708R/S/T)
Voltage Monitor for Power-Fail or Low Battery Warning
Guaranteed RESET Valid with V
Superior Upgrade for MAX706P/R/S/T, MAX708R/S/T

APPLICATIONS
Microprocessor Systems
Computers
Controllers
Intelligent Instruments
Critical ␮P Monitoring
Automotive Systems
Battery Operated Systems
Portable Instruments

= 1 V

CC

␮P Supervisory Circuits

ADM706P/R/S/T, ADM708R/S/T

FUNCTIONAL BLOCK DIAGRAMS

GENERAL DESCRIPTION

The ADM706P/R/S/T and the ADM708R/S/T microprocessor
supervisory circuits are suitable for monitoring either 3 V or 3.3 V
power supplies.

The ADM706P/R/S/T provide the following functions:

1. Power-supply monitoring circuitry which generates a Reset
output during power-up, power-down and brownout condi­tions. The reset output remains operational with V

as low

CC

as 1 V.

2. Independent watchdog monitoring circuitry which is acti­vated if the watchdog input has not been toggled within

1.6 seconds.

3. A 1.25 V threshold detector for power fail warning, low bat­tery detection, or to monitor an additional power supply.

4. An active low debounced manual reset input (MR).

The ADM706R, ADM706S, ADM706T are identical except for
the reset threshold monitor levels which are 2.63 V, 2.93 V, and

3.08 V respectively. The ADM706P is identical to the ADM706R

in that the reset threshold is 2.63 V. It differs only in that it has
an active high reset output.

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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.

The ADM708R/S/T provide the same functionality as the
ADM706R/S/T and only differ in that:

1. A watchdog timer function is not available.

2. An active high reset output (RESET) in addition to the

active low (RESET) output is available.

All parts are available in 8-lead DIP and narrow SOIC packages.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] World Wide Web Site: http://www.analog.com
Fax: [phone] © Analog Devices, Inc., 1999

(V

ADM706P/R/S/T, ADM708R/S/T–SPECIFICATIONS

V

= 3.00 V to 5.5 V (ADM70_S), V

CC

= 3.15 V to 5.5 V (ADM70_T), TA = T

CC

MIN

to T

unless otherwise noted.)

MAX

= 2.70 V to 5.5 V (ADM70_P/R),

CC

Parameter Min Typ Max Units Test Conditions/Comments

V

Operating Voltage Range 1.0 5.5 V

CC

Supply Current 100 200 µAV

150 350 µAV

Reset Threshold (V

) 2.55 2.63 2.70 V ADM70_P/R

RST

< 3.6 V

CC

< 5.5 V

CC

2.85 2.93 3.00 V ADM70_S

3.00 3.08 3.15 V ADM70_T

Reset Threshold Hysteresis 20 mV

Reset Pulsewidth 160 200 280 ms ADM70_P/R, V

160 200 280 ms ADM70_S/T, V

= 3 V

CC

= 3.3 V

CC

200 ms VCC = 5.0 V

RESET Output Voltage ADM70_R/S/T

V

OH

V

OL

V

OH

V

OL

V

OL

0.8 × V

CC

0.3 V V

VV

(max) < VCC < 3.6 V, I

RST

(max) < VCC < 3.6 V, I

RST

VCC–1.5 V V 4.5 V < VCC < 5.5 V, I

0.4 V 4.5 V < VCC < 5.5 V, I

0.3 V VCC = 1 V, I

SINK

= 100 µA

SOURCE

= 3.2 mA

SINK

SOURCE

SINK

= 800 µA

RESET Output Voltage ADM706P

V

OH

V

OL

V

OH

V

OL

VCC–0.6 V V V

0.3 V V

(max) < VCC < 3.6 V, I

RST

(max) < VCC < 3.6 V, I

RST

VCC–1.5 V V 4.5 V < VCC < 5.5 V, I

0.4 V 4.5 V < VCC < 5.5 V, I

SOURCE

= 3.2 mA

SINK

SOURCE

SINK

= 800 µA

RESET Output Voltage ADM708_

V

OH

V

OL

V

OH

V

OL

Watchdog Timeout Period 1.00 1.60 2.25 sec ADM70_P/R; V

WDI Pulsewidth V

0.8 × V

CC

0.3 V V

VV

(max) < VCC < 3.6 V, I

RST

(max) < VCC < 3.6 V, I

RST

VCC–1.5 V V 4.5 V < VCC < 5.5 V, I

0.4 V 4.5 V < VCC < 5.5 V, I

= 3 V. ADM70_S/T,

< 5.5 V

CC

CC

= 3.3 V

V

CC

= 0.4 V, VIH = (V

IL

100 ns V

(max) < VCC < 3.6 V

RST

50 ns 4.5 V < V

SOURCE

SINK

) × (0.8)

CC

SOURCE

SINK

= 800 µA

= 1.2 mA

WDI Input Threshold ADM706_

V

IL

V

IH

V

IL

V

IH

0.7 × V

CC

3.5 V VCC = 5.0 V

0.6 V V
VV

0.8 V VCC = 5.0 V

WDI Input Current –1.0 0.02 1.0 µA WDI = 0 V or V

(max) < VCC < 3.6 V

RST

(max) < VCC < 3.6 V

RST

CC

WDO Output Voltage

V

OH

V

OL

V

OH

V

OL

0.8 × V

CC

0.3 V V

VCC–1.5 V V 4.5 V < VCC < 5.5 V, I

0.4 V 4.5 V < VCC < 5.5 V, I

VV

(max) < VCC < 3.6 V, I

RST

(max) < VCC < 3.6 V, I

RST

SOURCE

= 1.2 mA

SINK

SOURCE

SINK

= 800 µA

MR Pull Up Current MR = 0 V

25 70 250 µAV
100 250 600 µA 4.5 V < V

(max) < VCC < 3.6 V

RST

< 5.5 V

CC

MR Pulsewidth

500 ns V

(max) < VCC < 3.6 V

RST

150 ns 4.5 V < VCC < 5.5 V

MR Input Threshold

V

IL

V

IH

V

IL

V

IH

0.7 × V

CC

2.0 V 4.5 V < VCC < 5.5 V

0.6 V V
VV

(max) < VCC < 3.6 V

RST

(max) < VCC < 3.6 V

RST

0.8 V 4.5 V < VCC < 5.5 V

= 500 µA

= 1.2 mA

= 215 µA

= 1.2 mA

= 500 µA

= 500 µA

= 500 µA

= 500 µA

REV. A–2–

ADM706P/R/S/T, ADM708R/S/T

Parameter Min Typ Max Units Test Conditions/Comments

MR to Reset Output Delay 750 ns V

250 ns 4.5 V < VCC < 5.5 V

PFI Input Threshold 1.2 1.25 1.3 V ADM70_P/R; V

PFI Input Current –25 0.01 25 nA
PFO Output Voltage

V

OH

V

OL

V

OH

V

OL

0.8 × V

CC

VV

0.3 V V

VCC–1.5 V V 4.5 V < VCC < 5.5 V, I

0.4 V 4.5 V < VCC < 5.5 V, I

(max) < VCC < 3.6 V

RST

= 3.3 V, PFI falling

V

CC

(max) < VCC < 3.6 V, I

RST

(max) < VCC < 3.6 V, I

RST

CC

= 3 V. ADM70_S/T,

SOURCE

SINK

= 800 µA

SOURCE

= 3.2 mA

SINK

= 500 µA

= 1.2 mA

ORDERING GUIDE

Temperature Package

Model Range Options

ADM706PAN –40°C to +85°C N-8
ADM706PAR –40°C to +85°C SO-8

ADM706RAN –40°C to +85°C N-8
ADM706RAR –40°C to +85°C SO-8

ADM706SAN –40°C to +85°C N-8
ADM706SAR –40°C to +85°C SO-8

ADM706TAN –40°C to +85°C N-8
ADM706TAR –40°C to +85°C SO-8

ADM708RAN –40°C to +85°C N-8
ADM708RAR –40°C to +85°C SO-8

ADM708SAN –40°C to +85°C N-8
ADM708SAR –40°C to +85°C SO-8

ADM708TAN –40°C to +85°C N-8
ADM708TAR –40°C to +85°C SO-8

ABSOLUTE MAXIMUM RATINGS*

(T

= +25°C unless otherwise noted)

A

VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +6 V

All Other Inputs . . . . . . . . . . . . . . . . . . –0.3 V to V

+ 0.3 V

CC

Input Current

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 mA

V

CC

GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 mA

Digital Output Current . . . . . . . . . . . . . . . . . . . . . . . . . 20 mA

Power Dissipation, N-8 DIP . . . . . . . . . . . . . . . . . . . .727 mW

Thermal Impedance . . . . . . . . . . . . . . . . . . . . . 135°C/W

θ

JA

Power Dissipation, SO-8 SOIC . . . . . . . . . . . . . . . . . . 470 mW

Thermal Impedance . . . . . . . . . . . . . . . . . . . . . 110°C/W

θ

JA

Operating Temperature Range

Industrial (A Version) . . . . . . . . . . . . . . . . . –40°C to +85°C

Lead Temperature (Soldering, 10 secs) . . . . . . . . . . . . +300°C

Vapor Phase (60 secs) . . . . . . . . . . . . . . . . . . . . . . . +215°C

Infrared (15 secs) . . . . . . . . . . . . . . . . . . . . . . . . . . . +220°C

Storage Temperature Range . . . . . . . . . . . . . –65°C to +150°C

ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .>5 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.

REV. A –3–