Microprocessor Supervisory
Circuit in 4-Lead SOT-143 with DSP
ADM811/ADM812
FEATURES
FUNCTIONAL BLOCK DIAGRAM
ADM811/ADM812
VCC
RESET
GENERATOR
VREF
MR
RESET/RESET
DEBOUNCE
00092-001
Superior upgrade for MAX811/MAX812
Specified over temperature
Low power consumption (5 μA typ)
Precision voltage monitor: 2.5 V, 3 V, 3.3 V, 5 V options
Reset assertion down to 1 VCC
140 ms min power-on reset
Logic low RESET output (ADM811)
Logic high RESET output (ADM812)
Built-in manual reset
GND
Figure 1.
APPLICATIONS
Microprocessor systems
Controllers
Intelligent instruments
Automotive systems
Safety systems
Portable instruments
GENERAL DESCRIPTION
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.
MR
VCC
VCC
ADM811
MICROPROCESSOR
SYSTEM
RESET
RESET
100kΩ
GND
GND
00092-002
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.
Figure 2. Typical ADM811 Operating Circuit
Rev. D
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. Specifications subject to change without notice. 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 owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
www.analog.com
Fax: 781.461.3113
©2006 Analog Devices, Inc. All rights reserved.
ADM811/ADM812
TABLE OF CONTENTS
Features .............................................................................................. 1
Reset Output ..................................................................................7
Applications....................................................................................... 1
Manual Reset..................................................................................7
Functional Block Diagram .............................................................. 1
Glitch Immunity............................................................................7
General Description ......................................................................... 1
Interfacing to Other Devices............................................................8
Specifications..................................................................................... 3
Output.............................................................................................8
Absolute Maximum Ratings............................................................ 4
Benefits of a Very Accurate Reset Threshold ............................8
ESD Caution.................................................................................. 4
Ensuring a Valid RESET/Reset Output Down to VCC = 0 V....8
Pin Configuration and Function Descriptions............................. 5
Outline Dimensions ..........................................................................9
Typical Performance Characteristics ............................................. 6
ADM811 Ordering Guide ............................................................9
Circuit Information .......................................................................... 7
ADM812 Ordering Guide ......................................................... 10
Reset Thresholds........................................................................... 7
REVISION HISTORY
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. D | Page 2 of 12
ADM811/ADM812
SPECIFICATIONS
VCC = full operating range; TA = TMIN to TMAX; VCC typ = 5 V for L/M, 3.3 V for T/S, 3 V for R, 2.5 V for Z models, unless otherwise noted.
Table 1.
Parameter
SUPPLY
Voltage
Min
Typ
1.0
1.2
Current
RESET VOLTAGE THRESHOLD
ADM81_L
ADM81_L
ADM81_M
ADM81_M
ADM81_T
ADM81_T
ADM81_S
ADM81_S
ADM81_R
ADM81_R
ADM81_Z
ADM81_Z
RESET THRESHOLD TEMPERATURE COEFFICIENT
VCC 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)
4.54
4.50
4.30
4.25
3.03
3.00
2.88
2.85
2.58
2.55
2.28
2.25
Max
Unit
Test Conditions/Comments
5.5
V
V
μA
μA
TA = 0°C to 70°C
TA = −40°C to +85°C
VCC < 5.5 V, ADM81_L/M, IOUT = 0 mA
VCC < 3.6 V, ADM81_R/S/T/Z, IOUT = 0 mA
TA = 25°C
TA = −40°C to +85°C
TA = 25°C
TA = −40°C to +85°C
TA = 25°C
TA = −40°C to +85°C
TA = 25°C
TA = −40°C to +85°C
TA = 25°C
TA = −40°C to +85°C
TA = 25°C
TA = −40°C to +85°C
560
700
V
V
V
V
V
V
V
V
V
V
V
V
ppm/°C
μs
μs
ms
ms
30
μs
ns
μs
kΩ
8
5
15
10
4.63
4.72
4.75
4.46
4.50
3.14
3.15
2.98
3.00
2.68
2.70
2.35
2.38
4.38
3.08
2.93
2.63
2.32
30
40
20
140
300
10
100
0.5
20
10
2.3
0.8
0.7 × VCC
0.25 × VCC
0.3
0.4
0.8 × VCC
0.3
0.4
0.3
0.8 × VCC
VCC × 1.5
Rev. D | Page 3 of 12
VOD = 125 mV, ADM81_L/M
VOD = 125 mV, ADM81_R/S/T/Z
VCC = VTH(MAX)
ADM811-3T only
V
V
V
V
VCC > VTH(MAX), ADM81_L/M
VCC > VTH(MAX), ADM81_L/M
VCC > VTH(MAX), ADM81_R/S/T/Z
VCC > VTH(MAX), ADM81_R/S/T/Z
V
V
V
V
V
V
V
V
VCC = VTH(MAX), ISINK = 1.2 mA
VCC = VTH(MAX), ISINK = 3.2 mA
1.8 V < VCC < VTH(MIN), ISOURCE = 150 μA
VCC = VTH(MIN), ISINK = 1.2 mA
VCC = VTH(MIN), ISINK = 3.2 mA
VCC > 1.0 V, ISINK = 50 μA
VCC > VTH(MAX), ISOURCE = 500 μA
VCC > VTH(MAX), ISOURCE = 800 μA
ADM811/ADM812
ABSOLUTE MAXIMUM RATINGS
Typical values are at TA = 25°C, unless otherwise noted.
Table 2.
Parameter
Terminal Voltage (With Respect to Ground)
VCC
All Other Inputs
Input Current
VCC
MR
Output Current
RESET
Power Dissipation (TA = 70°C)
RT-4 (SOT-143)
Derate by 4 mW/°C Above 70°C
θJA 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 VCC + 0.3 V
20 mA
20 mA
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.
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
ESD 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 this product features
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. D | Page 4 of 12
ADM811/ADM812
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
4
ADM811/
ADM812
VCC
TOP VIEW
RESET/RESET 2 (Not to Scale) 3 MR
00092-003
GND 1
Figure 3. Pin Configuration
Table 3. Pin Function Descriptions
Pin No.
1
2
Mnemonic
GND
RESET (ADM811)
RESET (ADM812)
3
MR
4
VCC
Function
0 V. Ground reference for all signals.
Active Low Logic Output. RESET remains low while VCC 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 VCC rises above the
reset threshold.
Active High Logic Output. RESET remains high while VCC is below the reset threshold or when MR is low;
RESET then remains high for 240 ms (typical) after VCC 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.
2.5 V, 3 V, 3.3 V, or 5 V Monitored Supply Voltage.
Rev. D | Page 5 of 12
ADM811/ADM812
TYPICAL PERFORMANCE CHARACTERISTICS
12
10
IDD @ VCC = 5.5V
9
10
7
8
IDD @ VCC = 3V
6
IDD (μA)
IDD (μA)
IDD @ VCC = 5.5V
8
6
IDD @ VCC = 3V
5
4
4
3
2
–20
0
20
30
50
70
TEMPERATURE (°C)
85
100
1
0
–40
120
900
900
800
POWER-DOWN RESET DELAY (μs)
1000
800
700
600
500
400
VOD = 20mV
300
200 VOD = 125mV
VOD = 200mV
100
0
–40
–20
0
20
30
50
70
TEMPERATURE (°C)
85
100
20
30
50
70
TEMPERATURE (°C)
85
100
120
700
600
500
400
VOD = 20mV
300
200
VOD = 125mV
100
VOD = 200mV
0
–40
120
Figure 5. Power-Down RESET Delay vs. Temperature (ADM81_R/S/T/Z)
–20
0
20
30
50
70
TEMPERATURE (°C)
85
100
120
Figure 8. Power-Down RESET Delay vs. Temperature (ADM81_L/M)
299
1.007
1.006
NORMALIZED RESET THRESHOLD
ADM81_LM
279
274
269
264
259
254
00092-006
ADM81_R/S/T/Z
249
244
–40
–20
0
20
30
50
70
TEMPERATURE (°C)
85
100
1.005
1.004
1.003
1.002
1.002
1.001
1.000
0.999
0.998
0.997
00092-009
294
POWER-UP RESET TIMEOUT (ms)
0
Figure 7. Supply Current vs. Temperature (ADM81_L/M)
00092-005
POWER-DOWN RESET DELAY (μs)
Figure 4. Supply Current vs. Temperature (ADM81_R/S/T/Z)
–20
00092-008
IDD @ VCC = 1V
0
–40
IDD @ VCC = 1V
00092-007
00092-004
2
0.996
0.995
–40
120
–20
0
20
30
50
70
TEMPERATURE (°C)
85
100
Figure 9. RESET Threshold Deviation vs. Temperature
Figure 6. Power-Up RESET Timeout vs. Temperature
Rev. D | Page 6 of 12
120
ADM811/ADM812
CIRCUIT INFORMATION
RESET THRESHOLDS
A reset output is provided to the microprocessor whenever the
VCC input is below the reset threshold. The actual reset threshold
depends on whether an L, M, T, S, R, or Z suffix is used. Refer
to Table 4.
Table 4. Reset Threshold Options
Reset Threshold (V)
4.63
4.38
3.08
3.08
2.93
2.63
2.32
4.63
4.38
3.08
2.93
2.63
2.32
During power-down of the ADM811, the RESET output
remains valid (low) with VCC as low as 1 V. This ensures that the
microprocessor 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.
MANUAL RESET
The ADM811/ADM812 are 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 can 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.
GLITCH IMMUNITY
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/ADM812 contain internal filtering circuitry
providing glitch immunity from fast transient glitches on the
power supply line.
Rev. D | Page 7 of 12
VCC
RESET
VREF
VREF
VREF
t1
VREF
t1
t1 = RESET TIME = 250ms TYPICAL
VREF = RESET VOLTAGE THRESHOLD
Figure 10. Power Fall RESET Timing
00092-010
Model
ADM811LART
ADM811MART
ADM811TART
ADM811-3TART
ADM811SART
ADM811RART
ADM811ZART
ADM812LART
ADM812MART
ADM812TART
ADM812SART
ADM812RART
ADM812ZART
The ADM811 provides an active low reset output (RESET)
while the ADM812 provides an active high output (RESET).
ADM811/ADM812
INTERFACING TO OTHER DEVICES
VCC
OUTPUT
The ADM811/ADM812 are designed to integrate with as many
devices as possible. One feature of the ADM811/ADM812 is the
reset output, which is directly proportional to VCC (this is
guaranteed only while VCC is greater than 1 V). This enables the
part to be used with both 3 V and 5 V, or any nominal voltage
within the minimum and maximum specifications for VCC.
VCC
ADM811
GND
00092-011
RESET
Figure 11. Ensuring a Valid RESET Output Down to VCC = 0 V
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.
ENSURING A VALID RESET/RESET
OUTPUT DOWN TO VCC = 0 V
When VCC falls below 0.8 V, the ADM811/ADM812’s RESET
/RESET no longer sinks current. Therefore, a high impedance
CMOS logic input connected to RESET/RESET can drift to
undetermined logic levels. To eliminate this problem, a 100 kΩ
resistor should be connected from RESET/RESET to ground.
Rev. D | Page 8 of 12
ADM811/ADM812
OUTLINE DIMENSIONS
3.04
2.90
2.80
1.40
1.30
1.20
4
3
1
2
2.64
2.10
PIN 1
1.92 BSC
1.07
0.90
0.75
0.15
0.05
0.50
0.30
0.89
0.76
0.20
0.08
SEATING
PLANE
8°
0°
0.54 REF
0.60
0.50
0.40
COMPLIANT TO JEDEC STANDARDS TO-253-AA
111605-0
1.22
0.80
Figure 12. 4-Lead Small Outline Transistor Package [SOT-143]
(RT-4)
Dimensions shown in millimeters
ADM811 ORDERING GUIDE
Model 1
Reset
Threshold (V)
ADM811LART-REEL
ADM811LART-REEL7
ADM811LARTZ-REEL 2
ADM811LARTZ-REEL72
ADM811MART-REEL
ADM811MART-REEL7
ADM811MARTZ-REEL2
ADM811MARTZ-REEL72
ADM811TART-REEL
ADM811TART-REEL7
ADM811TARTZ-REEL2
ADM811TARTZ-REEL72
ADM811-3TART-REEL
ADM811-3TART-REEL-7
ADM811-3TARTZ-RL2
ADM811-3TARTZ-RL72
ADM811SART-REEL
ADM811SART-REEL7
ADM811SARTZ-REEL2
ADM811SARTZ-REEL72
ADM811RART-REEL
ADM811RART-REEL7
ADM811RARTZ-REEL2
ADM811RARTZ-REEL72
ADM811ZART-REEL
ADM811ZART-REEL7
ADM811ZARTZ-REEL2
ADM811ZARTZ-REEL72
4.63
4.63
4.63
4.63
4.38
4.38
4.38
4.38
3.08
3.08
3.08
3.08
3.08
3.08
3.08
3.08
2.93
2.93
2.93
2.93
2.63
2.63
2.63
2.63
2.32
2.32
2.32
2.32
1
2
Temperature
Range
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
Ordering
Quantity
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
Only available in reels.
Z = Pb-free part, # denotes lead-free may be top or bottom marked.
Rev. D | Page 9 of 12
Package
Description
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
Package
Option
Branding
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
MBV
MBV
M4J
M4J
MBT
MBT
MBT#
MBT#
MBG
MBG
MBG#
MBG#
MB3
MB3
M4E
M4E
MBE
MBE
MBE#
MBE#
MBB
MBB
M4N
M4N
MBZ
MBZ
M6G
M6G
ADM811/ADM812
ADM812 ORDERING GUIDE
Model 1
Reset
Threshold (V)
Temperature
Range
ADM812LART-REEL
ADM812LART-REEL7
ADM812LARTZ-REEL2
ADM812LARTZ-REEL72
ADM812MART-REEL
ADM812MART-REEL7
ADM812MARTZ-REEL2
ADM812MARTZ-REEL72
ADM812TART-REEL
ADM812TART-REEL7
ADM812TARTZ-REEL2
ADM812TARTZ-REEL72
ADM812SART-REEL
ADM812SART-REEL7
ADM812SARTZ-REEL2
ADM812SARTZ-REEL72
ADM812RART-REEL
ADM812RART-REEL7
ADM812RARTZ-REEL2
ADM812RARTZ-REEL72
ADM812ZART-REEL
ADM812ZART-REEL7
ADM812ZARTZ-REEL 2
ADM812ZARTZ-REEL72
4.63
4.63
4.63
4.63
4.38
4.38
4.38
4.38
3.08
3.08
3.08
3.08
2.93
2.93
2.93
2.93
2.63
2.63
2.63
2.63
2.32
2.32
2.32
2.32
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
–40°C to +85°C
1
2
Ordering
Quantity
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
10,000
3,000
Package
Description
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
4-Lead SOT-143
Only available in reels.
Z = Pb-free part.
Rev. D | Page 10 of 12
Package
Option
Branding
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
RT-4
MCV
MCV
M5D
M5D
MCT
MCT
M6D
M6D
MCG
MCG
M68
M68
MCE
MCE
M67
M67
MCB
MCB
M6F
M6F
MCZ
MCZ
M69
M69
ADM811/ADM812
NOTES
Rev. D | Page 11 of 12
ADM811/ADM812
NOTES
©2006 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
C00092-0-5/06(D)
Rev. D | Page 12 of 12
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