Data Sheet
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
CC
Power-on reset: 140 ms minimum
Logic low RESET output (ADM811)
Logic high RESET output (ADM812)
Built-in manual reset
Microprocessor Supervisory
Circuit in 4-Lead SOT-143 with DSP
ADM811/ADM812
FUNCTIONAL BLOCK DIAGRAM
ADM811/ADM812
V
CC
V
REF
RESET
GENERATOR
RESET/RESET
MR
DEBOUNCE
GND
Figure 1.
APPLICATIONS
Microprocessor systems
Controllers
Intelligent instruments
Automotive systems
Safety systems
Portable instruments
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
V
CC
ADM811
MR
RESET
100kΩ
GND
MICROPROCESSOR
SYSTEM
RESET
GND
Figure 2. Typical ADM811 Operating Circuit
Rev. G
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00092-002
00092-001
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
Data Sheet
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 RESET/Reset Output Down to V
CC
= 0 V....8
Outline Dimensions ..........................................................................9
Ordering Guide .......................................................................... 10
REVISION HISTORY
3/13—Rev. F to Rev. G
Changes to Pin 4 Description; Table 3 ........................................... 5
Updated Outline Dimensions ......................................................... 9
Changes to Ordering Guide .......................................................... 10
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
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
Rev. G | Page 2 of 12
Data Sheet
SPECIFICATIONS
ADM811/ADM812
V
CC
= full operating range; T
A
= T
MIN
to T
MAX
; V
CC
typical = 5 V for L/M models, 3.3 V for T/S models, 3 V for R model, 2.5 V for Z
models, unless otherwise noted.
Table 1.
Parameter
SUPPLY
Voltage
Current
RESET VOLTAGE THRESHOLD
ADM81xL
ADM81xL
ADM81xM
ADM81xM
ADM81xT
ADM81xT
ADM81xS
ADM81xS
ADM81xR
ADM81xR
ADM81xZ
ADM81xZ
RESET THRESHOLD TEMPERATURE COEFFICIENT
V
CC
TO RESET/RESET DELAY
RESET ACTIVE TIMEOUT PERIOD
MANUAL RESET
Minimum Pulse Width
Glitch Immunity
RESET/RESET Propagation Delay
Pull-Up Resistance
The Manual Reset Circuit Acts On
An Input Rising Above
An Input Falling Below
An Input Rising Above
An Input Falling Below
RESET/RESET Output Voltage
Low (ADM812R/S/T/Z)
Low (ADM812L/M)
High (ADM812R/S/T/Z/L/M)
Low (ADM811R/S/T/Z)
Low (ADM811L/M)
Low (ADM811R/S/T/Z/L/M)
High (ADM811R/S/T/Z)
High (ADM811L/M)
Min
1.0
1.2
8
5
4.54
4.50
4.30
4.25
3.03
3.00
2.88
2.85
2.58
2.55
2.28
2.25
4.63
4.38
3.08
2.93
2.63
2.32
30
40
20
140
300
10
100
0.5
20
560
700
Typ
Max
5.5
15
10
4.72
4.75
4.46
4.50
3.14
3.15
2.98
3.00
2.68
2.70
2.35
2.38
Unit
V
V
µA
µA
V
V
V
V
V
V
V
V
V
V
V
V
ppm/°C
µs
µs
ms
ms
µs
ns
µs
kΩ
V
V
V
V
V
V
V
V
V
V
V
V
V
CC
> V
TH(MAX)
, ADM81xL/M
V
CC
> V
TH(MAX)
, ADM81xL/M
V
CC
> V
TH(MAX)
, ADM81xR/S/T/Z
V
CC
> V
TH(MAX)
, ADM81xR/S/T/Z
V
CC
= V
TH(MAX)
, I
SINK
= 1.2 mA
V
CC
= V
TH(MAX)
, I
SINK
= 3.2 mA
1.8 V < V
CC
< V
TH(MIN)
, I
SOURCE
= 150 µA
V
CC
= V
TH(MIN),
I
SINK
= 1.2 mA
V
CC
= V
TH(MIN)
, I
SINK
= 3.2 mA
V
CC
> 1.0 V, I
SINK
= 50 µA
V
CC
> V
TH(MAX)
, I
SOURCE
= 500 µA
V
CC
> V
TH(MAX)
, I
SOURCE
= 800 µA
Test Conditions/Comments
T
A
= 0°C to 70°C
T
A
= −40°C to +85°C
V
CC
< 5.5 V, ADM81xL/M, I
OUT
= 0 mA
V
CC
< 3.6 V, ADM81xR/S/T/Z, I
OUT
= 0 mA
T
A
= 25°C
T
A
= −40°C to +85°C
T
A
= 25°C
T
A
= −40°C to +85°C
T
A
= 25°C
T
A
= −40°C to +85°C
T
A
= 25°C
T
A
= −40°C to +85°C
T
A
= 25°C
T
A
= −40°C to +85°C
T
A
= 25°C
T
A
= −40°C to +85°C
V
OD
= 125 mV, ADM81xL/M
V
OD
= 125 mV, ADM81xR/S/T/Z
V
CC
= V
TH(MAX)
ADM811-3T only
10
2.3
30
0.8
0.7 × V
CC
0.25 × V
CC
0.3
0.4
0.8 × V
CC
0.3
0.4
0.3
0.8 × V
CC
V
CC
× 1.5
Rev. G | Page 3 of 12
ADM811/ADM812
ABSOLUTE MAXIMUM RATINGS
Typical values are at T
A
= 25°C, unless otherwise noted.
Table 2.
Parameter
Terminal Voltage (With Respect to Ground)
V
CC
All Other Inputs
Input Current
V
CC
MR
Output Current
RESET
Power Dissipation (T
A
= 70°C)
RA-4 (SOT-143)
Derate by 4 mW/°C Above 70°C
θ
JA
Thermal Impedance
Operating Temperature Range
Storage Temperature Range
Lead Temperature (Soldering, 10 sec)
Vapor Phase (60 sec)
Infrared (15 sec)
ESD Rating
Rating
−0.3 V to +6 V
−0.3 V to V
CC
+ 0.3 V
20 mA
20 mA
20 mA
200 mW
330°C/W
−40°C to +85°C
−65°C to +160°C
300°C
215°C
220°C
3 kV
Data Sheet
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. G | Page 4 of 12
Data Sheet
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
GND
1
4
ADM811/ADM812
ADM811/
ADM812
V
CC
Figure 3. Pin Configuration
Table 3. Pin Function Descriptions
Pin No.
1
2
Mnemonic
GND
RESET (ADM811)
Description
Ground Reference For All Signals, 0 V.
Active Low Logic Output. RESET remains low while V
CC
is below the reset threshold or when MR is low;
RESET then remains low for at least 140 ms (at least 300 ms for the ADM811-3T) after V
CC
rises above the
reset threshold.
Active High Logic Output. RESET remains high while V
CC
is below the reset threshold or when MR is low;
RESET then remains high for 240 ms (typical) after V
CC
rises above the reset threshold.
Manual Reset. This active low debounced input ignores 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.
Monitored Supply Voltage of 2.5 V, 3 V, 3.3 V, or 5 V. A 0.1 µF decoupling capacitor between V
CC
and the
GND pin is recommended.
RESET (ADM812)
3
4
MR
V
CC
Rev. G | Page 5 of 12
00092-003
TOP VIEW
RESET/RESET
2
(Not to Scale)
3
MR
