Analog Devices ADM811 2 c Datasheet

Microprocessor Supervisory

DEBOUNCE

RESET/RESET

GND

V

CC

V

REF

ADM811/ADM812

RESET

GENERATOR

MR

Circuit in 4-Lead SOT-143

ADM811/ADM812

FEATURES
Superior Upgrade for MAX811/MAX812
Specified over Temperature
Low Power Consumption (5 ␮A Typ)
Precision Voltage Monitor: 2.5 V, 3 V, 3.3 V, 5 V Options
Reset Assertion Down to 1 V V

CC

140 ms Min Power-On Reset

Logic Low RESET Output (ADM811)
Logic High RESET Output (ADM812)

Built-In Manual Reset

APPLICATIONS
Microprocessor Systems
Controllers
Intelligent Instruments
Automotive Systems
Safety Systems
Portable Instruments

GENERAL DESCRIPTION

The ADM811/ADM812 is a reliable voltage monitoring device
suitable for use in most voltage monitoring applications. The
ADM811/ADM812 is designed to monitor six different voltages,
each allowing for a 5% or 10% degradation of standard PSU
voltages before a reset occurs. These voltages have been selected
for the effective monitoring of 2.5 V, 3 V, 3.3 V, and 5 V supply
voltage levels.

Included in this circuit is a debounced manual reset input.
Reset can be activated using an electrical switch (or an input
from another digital device) or by a degradation of the supply
voltage. The manual reset function is very useful, especially if
the circuit in which the ADM811/ADM812 is operating enters
into a state that can only be detected by the user. Allowing the
user to reset a system manually can reduce the damage or
danger that could otherwise be caused by an out-of-control or
locked system.

FUNCTIONAL BLOCK DIAGRAM

MR

V

CC

ADM811

GND

MICROPROCESSOR

RESET

100k⍀

RESET

V

SYSTEM

GND

CC

Figure 1. Typical ADM811 Operating Circuit

REV. C

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. 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 companies.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] © 2003 Analog Devices, Inc. All rights reserved.

ADM811/ADM812–SPECIFICATIONS

(VCC = Full Operating Range; TA = T

3.3 V for T/S, 3 V for R, 2.5 V for Z Models; unless otherwise noted.)

MIN

to T

; VCC typ = 5 V for L/M,

MAX

Parameter Min Typ Max Unit Test Conditions/Comments

SUPPLY

Voltage 1.0 5.5 V T

1.2 V T

Current 8 15 µAV

510 µAV

= 0°C to 70°C

A

= –40°C to +85°C

A

< 5.5 V, ADM81_L/M, I

CC

< 3.6 V, ADM81_R/S/T/Z, I

CC

OUT

RESET VOLTAGE THRESHOLD

ADM81_L 4.54 4.63 4.72 V T
ADM81_L 4.50 4.75 V T
ADM81_M 4.30 4.38 4.46 V T
ADM81_M 4.25 4.50 V T
ADM81_T 3.03 3.08 3.14 V T
ADM81_T 3.00 3.15 V T
ADM81_S 2.88 2.93 2.98 V T
ADM81_S 2.85 3.00 V T
ADM81_R 2.58 2.63 2.68 V T
ADM81_R 2.55 2.70 V T
ADM81_Z 2.28 2.32 2.35 V T

= 25°C

A

= –40°C to +85°C

A

= 25°C

A

= –40°C to +85°C

A

= 25°C

A

= –40°C to +85°C

A

= 25°C

A

= –40°C to +85°C

A

= 25°C

A

= –40°C to +85°C

A

= 25°C

A

ADM81_Z 2.25 2.38 V TA = –40°C to +85°C

RESET THRESHOLD

TEMPERATURE COEFFICIENT 30 ppm/°C

TO RESET/RESET DELAY 40 µsV

V

CC

20 µsV

RESET ACTIVE TIMEOUT PERIOD 140 560 ms V

= 125 mV, ADM81_L/M

OD

= 125 mV, ADM81_R/S/T/Z

OD

= V

CC

TH(MAX)

300 700 ms (ADM811-3T Only)

MANUAL RESET

Minimum Pulsewidth 10 µs
Glitch Immunity 100 ns
RESET/RESET Propagation Delay 0.5 µs
Pull-Up Resistance 10 20 30 kΩ
The Manual Reset Circuit Will Act On:

An Input Rising Above 2.3 V V
An Input Falling Below 0.8 V V
An Input Rising Above 0.7 ⫻ V

CC

VV

An Input Falling Below 0.25 ⫻ VCCVV

CC

CC

CC

CC

> V
> V
> V
> V

TH(MAX),

TH(MAX),

TH(MAX),

TH(MAX),

ADM81_L/M
ADM81_L/M
ADM81_R/S/T/Z
ADM81_R/S/T/Z

RESET/RESET Output Voltage

Low (ADM812R/S/T/Z) 0.3 V V
Low (ADM812L/M) 0.4 V V
High (ADM812R/S/T/Z/L/M) 0.8 ⫻ V

CC

V 1.8 V < VCC < V
Low (ADM811R/S/T/Z) 0.3 V V
Low (ADM811L/M) 0.4 V V
Low (ADM811R/S/T/Z/L/M) 0.3 V V
High (ADM811R/S/T/Z) 0.8 ⫻ V
High (ADM811L/M) V

Specifications subject to change without notice.

CC

– 1.5 V VCC > V

CC

VV

= V

CC

= V

CC

= V

CC

= V

CC

> 1.0 V, I

CC

> V

CC

TH(MAX)

TH(MAX)

TH(MIN)

TH(MIN)

TH(MAX)

TH(MAX)

, I
, I

TH(MIN)

, I

SINK

, I

SINK

SINK

, I
, I

= 1.2 mA

SINK

= 3.2 mA

SINK

, I
= 1.2 mA
= 3.2 mA

= 50 µA

SOURCE

SOURCE

SOURCE

= 500 µA
= 800 µA

= 0 mA

= 0 mA

OUT

= 150 µA

REV. C–2–

ADM811/ADM812

ABSOLUTE MAXIMUM RATINGS*

(Typical values are at TA = 25°C, unless otherwise noted.)

Terminal Voltage (With Respect to Ground)

V

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

CC

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

+ 0.3 V

CC

Input Current

V

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

CC

MR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 mA

Output Current

RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 mA

Power Dissipation (T

= 70°C)

A

Operating Temperature Range . . . . . . . . . . . .–40°C to +85°C

Storage Temperature Range . . . . . . . . . . . . . –65°C to +160°C

Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . . . 300°C

Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . . . . 215°C

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

ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 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.

RT-4, (SOT-143) . . . . . . . . . . . . . . . . . . . . . . . . . . 200 mW

Derate by 4 mW/°C above 70°C

Thermal Impedance . . . . . . . . . . . . . . . . . . . . . 330°C/W

θ

JA

ORDERING GUIDE

Reset Temperature Branding

Model* Threshold (V) Range Information Quantity (K)

ADM811LART-REEL 4.63 –40°C to +85°C MBV 10
ADM811LART-REEL-7 4.63 –40°C to +85°C MBV 3
ADM811MART-REEL 4.38 –40°C to +85°C MBT 10
ADM811MART-REEL-7 4.38 –40°C to +85°C MBT 3
ADM811TART-REEL 3.08 –40°C to +85°C MBG 10
ADM811TART-REEL-7 3.08 –40°C to +85°C MBG 3
ADM811-3TART-REEL 3.08 –40°C to +85°CMB3 10
ADM811-3TART-REEL-7 3.08 –40°C to +85°CMB3 3
ADM811SART-REEL 2.93 –40°C to +85°C MBE 10
ADM811SART-REEL-7 2.93 –40°C to +85°C MBE 3
ADM811RART-REEL 2.63 –40°C to +85°CMBB 10
ADM811RART-REEL-7 2.63 –40°C to +85°CMBB 3
ADM811ZART-REEL 2.32 –40°C to +85°C MBZ 10
ADM811ZART-REEL-7 2.32 –40°C to +85°C MBZ 3
ADM812LART-REEL 4.63 –40°C to +85°C MCV 10
ADM812LART-REEL-7 4.63 –40°C to +85°C MCV 3
ADM812MART-REEL 4.38 –40°C to +85°C MCT 10
ADM812MART-REEL-7 4.38 –40°C to +85°C MCT 3
ADM812TART-REEL 3.08 –40°C to +85°C MCG 10
ADM812TART-REEL-7 3.08 –40°C to +85°C MCG 3
ADM812SART-REEL 2.93 –40°C to +85°C MCE 10
ADM812SART-REEL-7 2.93 –40°C to +85°C MCE 3
ADM812RART-REEL 2.63 –40°C to +85°CMCB 10
ADM812RART-REEL-7 2.63 –40°C to +85°CMCB 3
ADM812ZART-REEL 2.32 –40°C to +85°C MCZ 10
ADM812ZART-REEL-7 2.32 –40°C to +85°C MCZ 3

*Only available in reels.

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 the
ADM811/ADM812 feature 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. C

–3–

ADM811/ADM812

PIN CONFIGURATION

GND

RESET/RESET

1

ADM811/

ADM812

TOP VIEW

2

(Not to Scale)

4

V

CC

3

MR

PIN FUNCTION DESCRIPTIONS

Pin Mnemonic Function

1GND 0 V. Ground reference for all signals.
2 RESET (ADM811) Active Low Logic Output. RESET remains low while V

RESET then remains low for at least 140 ms (at least 300 ms for the ADM811-3T) after V

is below the reset threshold or when MR is low;

CC

rises above

CC

the reset threshold.

RESET (ADM812) Active High Logic Output. RESET remains high while V

RESET then remains high for 240 ms (typical) after V

is below the reset threshold or when MR is low;

CC

rises above the reset threshold.

CC

3 MR Manual Reset. This active low debounced input will ignore input pulses of 100 ns or less (typical) and is

guaranteed to accept input pulses of greater than 10 µs. Leave floating when not used.

4V

CC

2.5 V, 3 V, 3.3 V, or 5 V Monitored Supply Voltage.

–4–

REV. C

Typical Performance Characteristics—ADM811/ADM812

900

POWER-DOWN RESET DELAY – ␮s

800

700

600

500

400

300

200

100

0

VOD = 20mV

VOD = 200mV

VOD = 125mV

TEMPERATURE – ⴗC

–40 –20 0 20 30 50 70 85 100 120

12

10

8

6

– ␮A

DD

I

4

2

0

–40

–20 0 20 30 50 70 85 100 120

IDD @ VCC = 5.5V

IDD @ VCC = 3V

IDD @ VCC = 1V

TEMPERATURE – ⴗC

TPC 1. Supply Current vs. Temperature (ADM81_R/S/T/Z)

1000

900

800

700

600

500

400

300

200

POWER-DOWN RESET DELAY – ␮s

100

VOD = 200mV

0

–40 –20 0 20 30 50 70 85 100 120

TPC 2. Power-Down

VOD = 20mV

VOD = 125mV

RESET

TEMPERATURE – ⴗC

Delay vs. Temperature

(ADM81_R/S/T/Z)

10

9

8

7

6

5

– ␮A

DD

I

4

3

2

1

0

–40 –20 0 20 30 50 70 85 100 120

IDD @ VCC = 5.5V

IDD @ VCC = 3V

IDD @ VCC = 1V

TEMPERATURE – ⴗC

TPC 4. Supply Current vs. Temperature (ADM81_L/M)

TPC 5. Power-Down

RESET

Delay vs. Temperature

(ADM81_L/M)

289

284

279

274

269

264

259

REV. C

254

POWER-UP RESET TIMEOUT – ms

249

244

–40 –20 0 20 30 50 70 85 100 120

TPC 3. Power-Up Reset Timeout vs. Temperature

ADM81_L/M

ADM81_R/S/T/Z

TEMPERATURE – ⴗC

–5–

1.007

1.006

1.005

1.004

1.003

1.002

1.001

1.000

0.999

0.998

0.997

NORMALIZED RESET THRESHOLD

0.996

0.995
–40 –20 0 20 30 50 70 85 100 120

TEMPERATURE – ⴗC

TPC 6. Reset Threshold Deviation vs. Temperature

ADM811/ADM812

RESET

ADM811

GND

V

CC

V

CC

CIRCUIT INFORMATION
Reset Thresholds

A reset output is provided to the microprocessor whenever the

input is below the reset threshold. The actual reset thresh-

V

CC

old is dependent on whether an L, M, T, S, R, or Z suffix is
used. Refer to Table I.

Table I. Reset Threshold Options

Reset

Model Threshold (V)

ADM811LART 4.63
ADM811MART 4.38
ADM811TART 3.08
ADM811-3TART 3.08
ADM811SART 2.93
ADM811RART 2.63
ADM811ZART 2.32
ADM812LART 4.63
ADM812MART 4.38
ADM812TART 3.08
ADM812SART 2.93
ADM812RART 2.63
ADM812ZART 2.32

RESET OUTPUT

On power-up and after VCC rises above the reset threshold, an
internal timer holds the reset output active for 240 ms (typical).
This is intended as a power-on reset signal for the processor. It
allows time for both the power supply and the microprocessor to
stabilize after power-up. If a power supply brownout or inter­ruption occurs, the reset output is similarly activated and remains
active for 240 ms (typical) after the supply recovers. This allows
time for the power supply and microprocessor to stabilize.

The ADM811 provides an active low reset output (RESET)
while the ADM812 provides an active high output (RESET).

During power-down of the ADM811, the RESET output remains
valid (low) with V

as low as 1 V. This ensures that the micro-

CC

processor is held in a stable shutdown condition as the supply
falls and also ensures that no spurious activity can occur via
the microprocessor as it powers up.

Glitch Immunity

The ADM811/ADM812 contains internal filtering circuitry
providing glitch immunity from fast transient glitches on the
power supply line.

V

V

RESET

CC

V

REF

t

= RESET TIME = 240ms TYPICAL

1

V

= RESET VOLTAGE THRESHOLD

REF

Figure 2. Power Fail

V

REF

t

1

V

REF

t

1

RESET

Timing

REF

INTERFACING TO OTHER DEVICES
Output

The ADM811/ADM812 is designed to integrate with as many
devices as possible. One feature of the ADM811/ADM812 is
the reset output, which is directly proportional to V
guaranteed only while V

is greater than 1 V). This enables the

CC

(this is

CC

part to be used with both 3 V and 5 V, or any nominal voltage
within the minimum and maximum specifications for V

CC

.

BENEFITS OF A VERY ACCURATE RESET THRESHOLD

Because the ADM811/ADM812 can operate effectively even when
there are large degradations of the supply voltages, the possibility
of a malfunction during a power failure is greatly reduced. Another
advantage of the ADM811/ADM812 is its very accurate internal
voltage reference circuit. Combined, these benefits produce an
exceptionally reliable microprocessor supervisory circuit.

Figure 3. Ensuring a Valid
Down to V

= 0 V

CC

RESET

Output

MANUAL RESET

The ADM811/ADM812 is equipped with a manual reset input.
This input is designed to operate in a noisy environment where
unwanted glitches could be induced. These glitches could be
produced by the bouncing action of a switch contact, or where a
manual reset switch may be located some distance away from
the circuit (the cabling of which may pick-up noise).

The manual reset input is guaranteed to ignore logically valid
inputs that are faster than 100 ns and to accept inputs longer in
duration than 10 µs.

ENSURING A VALID RESET OUTPUT DOWN TO V

When VCC falls below 0.8 V, the ADM811/ADM812’s RESET
no longer sinks current. Therefore, a high impedance CMOS
logic input connected to RESET may drift to undetermined
logic levels. To eliminate this problem, a 100 kΩ resistor should
be connected from RESET to ground.

–6–

= 0 V

CC

REV. C

OUTLINE DIMENSIONS

4-Lead Small Outline Transistor Package [SOT-143]

(RT-4)

Dimensions shown in millimeters

1.92 BSC

ADM811/ADM812

1.40

1.20

PIN 1

0.15

0.05

SEATING

PLANE

4

1

0.20
BSC

COMPLIANT TO JEDEC STANDARDS TO-253D

3.04

2.80

0.89

0.76

3

2.64

2.10

2

1.22

0.80

0.20

0.08

0.45

0.30

0.60

0.40

8ⴗ
0ⴗ

REV. C

–7–

ADM811/ADM812

Revision History

Location Page

2/03—Data Sheet changed from REV. B to REV. C.

Changes FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Changes to GENERAL DESCRIPTION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

Changes to SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Removed Note 2 from ORDERING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Changes to PIN FUNCTION DESCRIPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Removed Note from Table I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

1/03—Data Sheet changed from REV. A to REV. B.

Added ADM812 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Universal

Changes SPECIFICATIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

Changes to ORDERING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

Changes to PIN CONFIGURATION . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Changes to PIN FUNCTION DESCRIPTIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Additions to Table I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Changes to Manual Reset section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

C00092–0–2/03(C)

5/02—Data Sheet changed from REV. 0 to REV. A.

Deletion of ADM812 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Universal

–8–

PRINTED IN U.S.A.

REV. C