ANALOG DEVICES ADM811, ADM812 Service Manual

Microprocessor Supervisory

V

FEATURES

Superior upgrade for MAX811/MAX812
Specified over temperature
Low power consumption: 5 μA typical
Precision voltage monitor: 2.5 V, 3 V, 3.3 V, 5 V options
Reset assertion down to 1 V
Power-on reset: 140 ms minimum
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

CC

Circuit in 4-Lead SOT-143 with DSP

ADM811/ADM812

FUNCTIONAL BLOCK DIAGRAM

ADM811/ADM812

CC

V

REF

MR

RESET

GENERATOR

DEBOUNCE

Figure 1.

RESET/RESE T

GND

0092-001

GENERAL DESCRIPTION

The ADM811/ADM812 are reliable voltage monitoring devices
suitable for use in most voltage monitoring applications. The
ADM811/ADM812 are designed to monitor six different
voltages, each allowing 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 are 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.

V

CC

ADM811

MR RESET

GND

Figure 2. Typical ADM811 Operating Circuit

100kΩ

V

CC

MICROPROCESSOR

SYSTEM

RESET

GND

0092-002

Rev. F

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ADM811/ADM812

TABLE OF CONTENTS

Features .............................................................................................. 1

Applications ....................................................................................... 1 

Functional Block Diagram .............................................................. 1

General Description ......................................................................... 1

Revision History ............................................................................... 2

Specifications ..................................................................................... 3

Absolute Maximum Ratings ............................................................ 4

ESD Caution .................................................................................. 4

Pin Configuration and Function Descriptions ............................. 5

Typical Performance Characteristics ............................................. 6

Circuit Information .......................................................................... 7

REVISION HISTORY

8/09—Rev. E to Rev. F

Changes to Ordering Guide .......................................................... 10

5/08—Rev. D to Rev. E

Changes to Table 2 ............................................................................ 4

Changes to Outline Dimensions ..................................................... 9

Changes to Ordering Guide .......................................................... 10

5/06—Rev. C to Rev. D

Changes to Ordering Guide ............................................................ 9

2/03—Rev. B to Rev. C

Changes Features .............................................................................. 1

Changes to General Description .................................................... 1

Changes to Specifications ................................................................ 2

Removed Note 2 from Ordering Guide ......................................... 3

Reset Thresholds ...........................................................................7

Reset Output ..................................................................................7

Manual Reset ..................................................................................7

Glitch Immunity ............................................................................7

Interfacing to Other Devices ............................................................8

Output .............................................................................................8

Benefits of a Very Accurate Reset Threshold ............................8

Ensuring a Valid

Outline Dimensions ..........................................................................9

Ordering Guide .......................................................................... 10

Changes to Pin Function Descriptions ........................................... 4

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

1/03—Rev. A to Rev. B

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

Changes to Specifications ................................................................. 2

Changes to Ordering Guide ............................................................. 3

Changes to Pin Configuration ......................................................... 4

Changes to Pin Function Description ............................................ 4

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

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

5/02—Rev. 0 to Rev. A

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

RESET

/Reset Output Down to VCC = 0 V....8

Rev. F | Page 2 of 12

ADM811/ADM812

SPECIFICATIONS

VCC = full operating range; TA = T
models, unless otherwise noted.

Table 1.

Parameter Min Typ Max Unit Test Conditions/Comments

SUPPLY

Voltage 1.0 5.5 V TA = 0°C to 70°C

1.2 V TA = −40°C to +85°C

Current 8 15 μA VCC < 5.5 V, ADM81xL/M, I
5 10 μA VCC < 3.6 V, ADM81xR/S/T/Z, I
RESET VOLTAGE THRESHOLD

ADM81xL 4.54 4.63 4.72 V TA = 25°C

ADM81xL 4.50 4.75 V TA = −40°C to +85°C

ADM81xM 4.30 4.38 4.46 V TA = 25°C

ADM81xM 4.25 4.50 V TA = −40°C to +85°C

ADM81xT 3.03 3.08 3.14 V TA = 25°C

ADM81xT 3.00 3.15 V TA = −40°C to +85°C

ADM81xS 2.88 2.93 2.98 V TA = 25°C

ADM81xS 2.85 3.00 V TA = −40°C to +85°C

ADM81xR 2.58 2.63 2.68 V TA = 25°C

ADM81xR 2.55 2.70 V TA = −40°C to +85°C

ADM81xZ 2.28 2.32 2.35 V TA = 25°C

ADM81xZ 2.25 2.38 V TA = −40°C to +85°C
RESET THRESHOLD TEMPERATURE COEFFICIENT 30 ppm/°C
VCC TO RESET/RESET DELAY
20 μs VOD = 125 mV, ADM81xR/S/T/Z
RESET ACTIVE TIMEOUT PERIOD 140 560 ms VCC = V
300 700 ms ADM811-3T only
MANUAL RESET

Minimum Pulse Width 10 μs

Glitch Immunity 100 ns

RESET/RESET Propagation Delay

Pull-Up Resistance 10 20 30 kΩ

The Manual Reset Circuit Acts On

An Input Rising Above 2.3 V VCC > V
An Input Falling Below 0.8 V VCC > V
An Input Rising Above 0.7 × VCC V VCC > V
An Input Falling Below

RESET/RESET Output Voltage

Low (ADM812R/S/T/Z) 0.3 V VCC = V

Low (ADM812L/M) 0.4 V VCC = V

High (ADM812R/S/T/Z/L/M) 0.8 × VCC V 1.8 V < VCC < V

Low (ADM811R/S/T/Z) 0.3 V VCC = V

Low (ADM811L/M) 0.4 V VCC = V

Low (ADM811R/S/T/Z/L/M) 0.3 V VCC > 1.0 V, I

High (ADM811R/S/T/Z) 0.8 × VCC V VCC > V

High (ADM811L/M) VCC × 1.5 V VCC > V

MIN

to T

; VCC typical = 5 V for L/M models, 3.3 V for T/S models, 3 V for R model, 2.5 V for Z

MAX

OUT

40 μs V

= 125 mV, ADM81xL/M

OD

TH(MAX)

0.5 μs

, ADM81xL/M

TH(MAX)

, ADM81xL/M

TH(MAX)

, ADM81xR/S/T/Z

0.25 × VCC V VCC > V

TH(MAX)

, ADM81xR/S/T/Z

TH(MAX)

, I

SINK

, I

SINK

TH(MIN)

, I

SINK

= 50 μA

SINK

, I

SOURCE

, I

SOURCE

= 1.2 mA
= 3.2 mA

, I

SOURCE

= 1.2 mA

= 3.2 mA

= 500 μA
= 800 μA

TH(MAX)

TH(MAX)

TH(MIN), ISINK

TH(MIN)

TH(MAX)

TH(MAX)

= 0 mA

= 0 mA

OUT

= 150 μA

Rev. F | Page 3 of 12

ADM811/ADM812

ABSOLUTE MAXIMUM RATINGS

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

Table 2.

Parameter Rating

Terminal Voltage (With Respect to Ground)

V

−0.3 V to +6 V

CC

All Other Inputs −0.3 V to VCC + 0.3 V

Input Current

VCC 20 mA
MR

Output Current

RESET

Power Dissipation (TA = 70°C)

RA-4 (SOT-143) 200 mW

Derate by 4 mW/°C Above 70°C

θJA Thermal Impedance

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 sec) 220°C

ESD Rating 3 kV

20 mA

20 mA

330°C/W

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

ESD CAUTION

Rev. F | Page 4 of 12