Analog Devices ADM708TAR, ADM708TAN, ADM708SAR, ADM708SAN, ADM708RAR Datasheet

FUNCTIONAL BLOCK DIAGRAMS

REV. A

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a

+3 V, Voltage Monitoring

␮P Supervisory Circuits

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

CC

= 1 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

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

CC

as low

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.

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

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

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

Parameter Min Typ Max Units Test Conditions/Comments

V

CC

Operating Voltage Range 1.0 5.5 V

Supply Current 100 200 µAV

CC

< 3.6 V

150 350 µAV

CC

< 5.5 V

Reset Threshold (V

RST

) 2.55 2.63 2.70 V ADM70_P/R

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

CC

= 3 V

160 200 280 ms ADM70_S/T, V

CC

= 3.3 V

200 ms VCC = 5.0 V

RESET Output Voltage ADM70_R/S/T

V

OH

0.8 × V

CC

VV

RST

(max) < VCC < 3.6 V, I

SOURCE

= 500 µA

V

OL

0.3 V V

RST

(max) < VCC < 3.6 V, I

SINK

= 1.2 mA

V

OH

VCC–1.5 V V 4.5 V < VCC < 5.5 V, I

SOURCE

= 800 µA

V

OL

0.4 V 4.5 V < VCC < 5.5 V, I

SINK

= 3.2 mA

V

OL

0.3 V VCC = 1 V, I

SINK

= 100 µA

RESET Output Voltage ADM706P

V

OH

VCC–0.6 V V V

RST

(max) < VCC < 3.6 V, I

SOURCE

= 215 µA

V

OL

0.3 V V

RST

(max) < VCC < 3.6 V, I

SINK

= 1.2 mA

V

OH

VCC–1.5 V V 4.5 V < VCC < 5.5 V, I

SOURCE

= 800 µA

V

OL

0.4 V 4.5 V < VCC < 5.5 V, I

SINK

= 3.2 mA

RESET Output Voltage ADM708_

V

OH

0.8 × V

CC

VV

RST

(max) < VCC < 3.6 V, I

SOURCE

= 500 µA

V

OL

0.3 V V

RST

(max) < VCC < 3.6 V, I

SINK

= 500 µA

V

OH

VCC–1.5 V V 4.5 V < VCC < 5.5 V, I

SOURCE

= 800 µA

V

OL

0.4 V 4.5 V < VCC < 5.5 V, I

SINK

= 1.2 mA

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

CC

= 3 V. ADM70_S/T,

V

CC

= 3.3 V

WDI Pulsewidth V

IL

= 0.4 V, VIH = (V

CC

) × (0.8)

100 ns V

RST

(max) < VCC < 3.6 V

50 ns 4.5 V < V

CC

< 5.5 V

WDI Input Threshold ADM706_

V

IL

0.6 V V

RST

(max) < VCC < 3.6 V

V

IH

0.7 × V

CC

VV

RST

(max) < VCC < 3.6 V

V

IL

0.8 V VCC = 5.0 V

V

IH

3.5 V VCC = 5.0 V

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

CC

WDO Output Voltage

V

OH

0.8 × V

CC

VV

RST

(max) < VCC < 3.6 V, I

SOURCE

= 500 µA

V

OL

0.3 V V

RST

(max) < VCC < 3.6 V, I

SINK

= 500 µA

V

OH

VCC–1.5 V V 4.5 V < VCC < 5.5 V, I

SOURCE

= 800 µA

V

OL

0.4 V 4.5 V < VCC < 5.5 V, I

SINK

= 1.2 mA

MR Pull Up Current MR = 0 V

25 70 250 µAV

RST

(max) < VCC < 3.6 V

100 250 600 µA 4.5 V < V

CC

< 5.5 V

MR Pulsewidth

500 ns V

RST

(max) < VCC < 3.6 V

150 ns 4.5 V < VCC < 5.5 V

MR Input Threshold

V

IL

0.6 V V

RST

(max) < VCC < 3.6 V

V

IH

0.7 × V

CC

VV

RST

(max) < VCC < 3.6 V

V

IL

0.8 V 4.5 V < VCC < 5.5 V

V

IH

2.0 V 4.5 V < VCC < 5.5 V

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

REV. A–2–

(V

CC

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

V

CC

= 3.00 V to 5.5 V (ADM70_S), V

CC

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

MIN

to T

MAX

unless otherwise noted.)

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

Parameter Min Typ Max Units Test Conditions/Comments

MR to Reset Output Delay 750 ns V

RST

(max) < VCC < 3.6 V

250 ns 4.5 V < VCC < 5.5 V

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

CC

= 3 V. ADM70_S/T,

V

CC

= 3.3 V, PFI falling

PFI Input Current –25 0.01 25 nA
PFO Output Voltage

V

OH

0.8 × V

CC

VV

RST

(max) < VCC < 3.6 V, I

SOURCE

= 500 µA

V

OL

0.3 V V

RST

(max) < VCC < 3.6 V, I

SINK

= 1.2 mA

V

OH

VCC–1.5 V V 4.5 V < VCC < 5.5 V, I

SOURCE

= 800 µA

V

OL

0.4 V 4.5 V < VCC < 5.5 V, I

SINK

= 3.2 mA

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

ABSOLUTE MAXIMUM RATINGS*

(T

A

= +25°C unless otherwise noted)

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

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

CC

+ 0.3 V
Input Current
V

CC

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

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

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

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

θ

JA

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

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

θ

JA

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

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–