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Part Number ADM809-5S

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REV. 0
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
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.
a
ADM809-5S/L
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
World Wide Web Site: http://www.analog.com
Fax: 781/326-8703
© Analog Devices, Inc., 2000
Microprocessor
Supervisory Circuit
FUNCTIONAL BLOCK DIAGRAM
V
REF
V
CC
RESET
GENERATOR
55ms
ADM809-5S/L
RESET
GND
FEATURES
Specified Over Temperature
Low Power Consumption (17 A)
Precision Voltage Monitor: 3 V, 5 V Options
Reset Assertion Down to 1 V V
CC
30 ms min Power-On Reset
Logic Low
RESET Output
APPLICATIONS
Microprocessor Systems
Computers
Controllers
Intelligent Instruments
Automotive Systems
GENERAL DESCRIPTION
The ADM809-5S/L supervisory circuits monitor the power
supply voltage in microprocessor systems. It provides a reset
output during power-up, power-down and brownout conditions.
On power-up, an internal timer holds reset asserted for 55 ms.
This holds the microprocessor in a reset state until conditions
have stabilized. The
RESET output remains operational with
V
CC
as low as 1 V. The ADM809-5S/L provides an active low
reset signal (
RESET).
The reset comparator features built-in glitch immunity,
making it immune to fast transients on V
CC
.
The ADM809-5S/L consumes only 17
µA, making it suitable
for low power portable equipment.
RESET
RESET
INPUT
GND
GND
V
CC
V
CC
P
SYSTEM
ADM809-5S/L
V
CC
Figure 1. Typical Operating Circuit
­2­
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ADM809-5S/L­SPECIFICATIONS
Parameter
Min
Typ Max
Unit
Test Conditions/Comments
V
CC
Operating Voltage Range
1.0
3.3
5.5
V
T
A
= 0
°C to +150°C with 100 k Pull-Down on Output
(Figure 3)
1.2
3.3
5.5
V
T
A
= ­40
°C to +150°C with 22 k External Pull-Up
on Output (Figure 6)
Supply Current
24
60
µA
V
CC
< 5.5 V, ADM8_L, T
A
= ­40
°C to +85°C
17
50
µA
V
CC
< 3.6 V, ADM8_S, T
A
= ­40
°C to +85°C
100
µA
V
CC
< 5.5 V, ADM8_L, T
A
= +85
°C to +150°C
100
µA
V
CC
< 3.6 V, ADM8_S, T
A
= +85
°C to +150°C
RESET THRESHOLD
Reset Voltage Threshold
ADM809-5L
4.5
4.75
V
T
A
= ­40
°C to +85°C
ADM809-5L
4.40
4.86
V
T
A
= +85
°C to +150°C
ADM809-5S
2.85
3.00
V
T
A
= ­40
°C to +85°C
ADM809-5S
2.78
3.08
V
T
A
= +85
°C to +150°C
Reset Threshold Temperature Coefficient
30
ppm/
°C
V
CC
to Reset Delay
20
µs
V
CC
= V
TH
to (V
TH
­100 mV)
Reset Active Timeout Period
30
55
80
ms
T
A
= ­40
°C to +150°C
RESET Output Voltage Low
0.3
V
V
CC
= V
TH
min, I
SINK
= 1.2 mA, ADM809-5S
0.4
V
V
CC
= V
TH
min, I
SINK
= 3.2 mA, ADM809-5L
0.3
V
V
CC
>1.0 V, I
SINK
= 50
µA, T
A
= 0
°C to +150°C
V
CC
>1.2 V, I
SINK
= 50
µA, T
A
= ­40
°C to +150°C
RESET Output Voltage High
0.8 V
CC
V
V
CC
> V
TH
max, I
SOURCE
= 500
µA
V
CC
­ 1.5
V
V
CC
> V
TH
max, I
SOURCE
= 800
µA
JUNCTION TEMPERATURE
­40
+150
°C
(V
CC
= Full Operating Range, T
A
= T
MIN
to T
MAX
, V
CC
typ = 5 V for L, 3.3 V for S
Models unless otherwise noted.)
ABSOLUTE MAXIMUM RATINGS
*
(T
A
= 25
°C unless otherwise noted)
V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ­0.3 V to +6 V
RESET,
RESET . . . . . . . . . . . . . . . . . . ­0.3 V to V
CC
+ 0.5 V
Input Current
V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 mA
Output Current
RESET,
RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 mA
Rate of Rise, V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 V/
µs
Power Dissipation, RT-3 SOT-23
Derate by 4 mW/
°C above 70°C . . . . . . . . . . . . . . . 320 mW
JA
Thermal Impedance . . . . . . . . . . . . . . . . . . . . . 333
°C/W
Lead Temperature (Soldering, 10 sec) . . . . . . . . . . . . . 300
°C
Vapor Phase (60 sec) . . . . . . . . . . . . . . . . . . . . . . . . . 215
°C
Infrared (15 sec) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220
°C
Storage Temperature Range . . . . . . . . . . . . . ­65
°C to +150°C
*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.
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 ADM809-5S/L 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.
WARNING!
ESD SENSITIVE DEVICE
ADM809-5S/L
­3­
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PIN FUNCTION DESCRIPTION
Pin
Mnemonic
Function
1
GND
0 V. Ground reference for all
signals.
2
RESET
Active Low Logic Output.
RESET
remains low while V
CC
is below the
reset threshold, and remains low
for 55 ms (typ) after V
CC
rises
above the reset threshold
3
V
CC
Supply voltage being monitored.
PIN CONFIGURATION
1
2
TOP VIEW
(Not to Scale)
ADM809-
5S/L
GND
3
RESET
V
CC
V
CC
RESET
t1
t1
V
REF
V
REF
V
REF
V
REF
t1 =
RESET TIME = 55ms TYP.
V
REF
=
RESET VOLTAGE THRESHOLD
Figure 2. Power Fail
Reset Timing
Table I.
RESET Threshold Options
RESET
Model
Threshold
ADM809-5LART
4.63 V
ADM809-5SART
2.93 V
ORDERING GUIDE
Reset
Temperature
Branding
Model
Threshold
Range
Information
Quantity
ADM809-5LART-REEL
4.63 V
­40
°C to +150°C
M9L
10K
ADM809-5LART-REEL-7
4.63 V
­40
°C to +150°C
M9L
3K
ADM809-5SART-REEL
2.93 V
­40
°C to +150°C
M9S
10K
ADM809-5SART-REEL-7
2.93 V
­40
°C to +150°C
M9S
3K
ADM809-5SCHIPS
2.93 V
­40
°C to +150°C
NA
1 Wafer
ADM809-5S/L
­4­
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TEMPERATURE ­ C
30
0
­40
­20
0
20
40
60
80
25
20
15
10
5
85
V
CC
= 5V
V
CC
= 3V
V
CC
= 1V
SUPPLY CURRENT
TPC 1. Supply Current vs. Tempera-
ture (No Load)
TEMPERATURE ­ C
0
­40
­20
0
20
40
60
80
20
40
60
80
100
120
140
160
180
85
V
OD
= V
TH
­ V
CC
V
OD
= 20mV
V
OD
= 100mV
V
OD
= 200mV
V
OD
= 10mV
RESET DELAY
TPC 4. Power-Down RESET Delay vs.
Temperature ADM809-5S
­Typical Performance Characteristics
ADM8_L/M
400
350
0
1
10
1000
100
300
250
50
200
150
100
ADM8_R/S/T
TITLE
TITLE
TPC 2. Maximum Transient Duration
Without Causing a RESET Pulse vs.
RESET Comparator Overdrive
TEMPERATURE ­ C
0.999
­40
­20
0
20
40
60
80
1.002
1.0015
1.001
1.0005
1.0
0.9995
85
THRESHOLD
TPC 5. Normalized RESET Voltage
Threshold vs. Temperature
TEMPERATURE ­ C
0
­40
­20
0
20
40
60
80
20
40
60
80
100
120
140
160
180
200
85
V
OD
= V
TH
­ V
CC
V
OD
= 20mV
V
OD
= 100mV
V
OD
= 200mV
V
OD
= 10mV
RESET DELAY
TPC 3. Power-Down RESET Delay vs.
Temperature ADM809-5L
ADM809-5S/L
­5­
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INTERFACING TO OTHER DEVICES OUTPUT
The ADM809-5S/L is designed to integrate with as many devices
as possible and therefore has an output dependant on V
CC
.
Because of this design approach, interfacing this device to other
devices is simplified.
ENSURING A VALID RESET OUTPUT DOWN TO V
CC
= 0 V
When V
CC
falls below 0.8 V, ADM809-5S/L's
RESET no longer
sinks current. A high impedance CMOS logic input connected
to
RESET may, therefore, drift to undetermined logic levels. To
eliminate this problem a 100 k
resistor should be connected
from
RESET to ground.
V
CC
V
CC
GND
RESET
ADM809-5S/L
100k
Figure 3. Ensuring a Valid
RESET Output Down to
V
CC
= 0 V
THE BENEFITS OF A VERY ACCURATE
RESET
THRESHOLD
In other microprocessor supervisory circuits, tolerances in supply
voltages lead to an overall increase in
RESET tolerance levels
due to the deterioration of the microprocessor
RESET circuit's
power supply. The possibility of a malfunction during a power
failure is greatly reduced because the ADM809-5S/L series can
operate effectively even when there are large degradations of the
supply voltages. Another advantage of the ADM809-5S/L series
is its very accurate internal voltage reference circuit. These
benefits combine to produce an exceptionally reliable Voltage
Monitor Circuit.
INTERFACING TO MICROPROCESSORS WITH
MULTIPLE INTERRUPTS
In a number of cases it is necessary to interface many interrupts
from different devices (i.e., thermal, attitude, and velocity sen-
sors). The ADM809-5S/L can easily be integrated into existing
interrupt-handling circuits (Figure 6) or used as a stand-alone
device.
PRIORITY ENCODER
74LS147
4 LINE BCD
TO µP
V
CC
ADM809
GND
RESET
OTHER SENSING
DEVICES
V
CC
Figure 4. Interfacing to
µPs with Multiple Interrupts
47k
47k
100nF
3.3V
V
CC
GND
RESET
ADM809-5S/L
Figure 5. Alternative Application Circuit with Extra
Decoupling
22k
100nF
3.3V
V
CC
GND
RESET
ADM809-5S/L
Figure 6. Additional Decoupling Can Be Achieved
Using a 100 nF Capacitor Between V
CC
and Ground
ADM809-5S/L
­6­
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OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
Surface Mount Package
RT-3
0.1200 (3.048)
0.1102 (2.799)
PIN 1
0.0550 (1.397)
0.0470 (1.194)
0.0236 (0.599)
0.0177 (0.450)
0.1040 (2.642)
0.0827 (2.101)
0.0413 (1.049)
0.0374 (0.950)
0.0807 (2.050)
0.0701 (1.781)
1
2
3
SEATING
PLANE
0.0440 (1.118)
0.0320 (0.813)
0.0040 (0.102)
0.0005 (0.013)
0.0210 (0.533)
0.0146 (0.371)
0.027 (0.686)
REF
0.0059 (0.150)
0.0034 (0.086)
0.0100 (0.254)
0.0050 (0.127)
C00090­2.5­9/00 (rev. 0)
PRINTED IN U.S.A.