AD ADM809-5LART-REEL Microprocessor supervisory circuit Datasheet

a
Microprocessor
Supervisory Circuit
ADM809-5S/L
FUNCTIONAL BLOCK DIAGRAM
FEATURES
Specified Over Temperature
Low Power Consumption (17 ␮A)
Precision Voltage Monitor: 3 V, 5 V Options
Reset Assertion Down to 1 V VCC
30 ms min Power-On Reset
Logic Low RESET Output
ADM809-5S/L
VCC
RESET
GENERATOR
55ms
VREF
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
VCC 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 VCC.
RESET
GND
VCC
VCC
VCC
ADM809-5S/L
RESET
GND
RESET
INPUT
␮P
SYSTEM
GND
Figure 1. Typical Operating Circuit
The ADM809-5S/L consumes only 17 µA, making it suitable
for low power portable equipment.
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.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700
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Fax: 781/326-8703
© Analog Devices, Inc., 2000
(VCC = Full Operating Range, TA = TMIN to TMAX, VCC typ = 5 V for L, 3.3 V for S
ADM809-5S/L–SPECIFICATIONS Models unless otherwise noted.)
Parameter
VCC Operating Voltage Range
Min
Typ Max
Unit
Test Conditions/Comments
1.0
3.3
5.5
V
1.2
3.3
5.5
V
24
17
60
50
100
100
µA
µA
µA
µA
TA = 0°C to +150°C with 100 kΩ Pull-Down on Output
(Figure 3)
TA = –40°C to +150°C with 22 kΩ External Pull-Up
on Output (Figure 6)
VCC < 5.5 V, ADM8_L, TA = –40°C to +85°C
VCC < 3.6 V, ADM8_S, TA = –40°C to +85°C
VCC < 5.5 V, ADM8_L, TA = +85°C to +150°C
VCC < 3.6 V, ADM8_S, TA = +85°C to +150°C
4.75
4.86
3.00
3.08
V
V
V
V
TA = –40°C to +85°C
TA = +85°C to +150°C
TA = –40°C to +85°C
TA = +85°C to +150°C
Supply Current
RESET THRESHOLD
Reset Voltage Threshold
ADM809-5L
ADM809-5L
ADM809-5S
ADM809-5S
4.5
4.40
2.85
2.78
Reset Threshold Temperature Coefficient
VCC to Reset Delay
Reset Active Timeout Period
30
20
30
RESET Output Voltage Low
RESET Output Voltage High
0.8 VCC
VCC – 1.5
JUNCTION TEMPERATURE
–40
55
ppm/°C
µs
VCC = VTH to (VTH –100 mV)
80
ms
TA = –40°C to +150°C
0.3
0.4
0.3
V
V
V
VCC = VTH min, ISINK = 1.2 mA, ADM809-5S
VCC = VTH min, ISINK = 3.2 mA, ADM809-5L
VCC >1.0 V, ISINK = 50 µA, TA = 0°C to +150°C
VCC >1.2 V, ISINK = 50 µA, TA = –40°C to +150°C
V
V
VCC > VTH max, ISOURCE = 500 µA
VCC > VTH max, ISOURCE = 800 µA
+150 °C
θJA 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
ABSOLUTE MAXIMUM RATINGS*
(TA = 25°C unless otherwise noted)
VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to +6 V
RESET, RESET . . . . . . . . . . . . . . . . . . –0.3 V to VCC + 0.5 V
Input Current
VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 mA
Output Current
RESET, RESET . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 mA
Rate of Rise, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100 V/µs
Power Dissipation, RT-3 SOT-23
Derate by 4 mW/°C above 70°C . . . . . . . . . . . . . . . 320 mW
*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 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.
–2–
WARNING!
ESD SENSITIVE DEVICE
REV. 0
ADM809-5S/L
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 VCC is below the
reset threshold, and remains low
for 55 ms (typ) after VCC rises
above the reset threshold
3
V CC
VREF
VCC
RESET
RESET 2
VREF
t1
t1 = RESET TIME = 55ms TYP.
VREF = RESET VOLTAGE THRESHOLD
Figure 2. Power Fail Reset Timing
Table I. RESET Threshold Options
PIN CONFIGURATION
ADM8095S/L
VREF
t1
Supply voltage being monitored.
GND 1
VREF
Model
RESET
Threshold
ADM809-5LART
ADM809-5SART
4.63 V
2.93 V
3 VCC
TOP VIEW
(Not to Scale)
ORDERING GUIDE
Model
Reset
Threshold
Temperature
Range
Branding
Information
Quantity
ADM809-5LART-REEL
ADM809-5LART-REEL-7
ADM809-5SART-REEL
ADM809-5SART-REEL-7
ADM809-5SCHIPS
4.63 V
4.63 V
2.93 V
2.93 V
2.93 V
–40°C to +150°C
–40°C to +150°C
–40°C to +150°C
–40°C to +150°C
–40°C to +150°C
M9L
M9L
M9S
M9S
NA
10K
3K
10K
3K
1 Wafer
REV. 0
–3–
ADM809-5S/L –Typical Performance Characteristics
30
VOD = VTH – VCC
180
350
VOD = 10mV
160
20
VCC = 3V
RESET DELAY
300
250
TITLE
SUPPLY CURRENT
25
200
400
VCC = 5V
15
200
150
10
ADM8_L/M
140
120
100
VOD = 20mV
80
60
100
0
–40
VOD = 100mV
40
5
50 ADM8_R/S/T
VCC = 1V
–20
0
20
40
60
TEMPERATURE – ⴗC
10
100
1000
TITLE
TPC 1. Supply Current vs. Temperature (No Load)
180
0
1
80 85
20
TPC 2. Maximum Transient Duration
Without Causing a RESET Pulse vs.
RESET Comparator Overdrive
VOD = VTH – VCC
1.002
VOD = 10mV
1.0015
0
–40
VOD = 200mV
–20
0
20
40
60
TEMPERATURE – ⴗC
80 85
TPC 3. Power-Down RESET Delay vs.
Temperature ADM809-5L
160
120
100
THRESHOLD
RESET DELAY
140
VOD = 20mV
80
60
40
1.0005
1.0
VOD = 100mV
0.9995
20
0
–40
1.001
VOD = 200mV
–20
0
20
40
60
TEMPERATURE – ⴗC
80 85
TPC 4. Power-Down RESET Delay vs.
Temperature ADM809-5S
0.999
–40
–20
0
20
40
60
TEMPERATURE – ⴗC
80 85
TPC 5. Normalized RESET Voltage
Threshold vs. Temperature
–4–
REV. 0
ADM809-5S/L
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 VCC.
Because of this design approach, interfacing this device to other
devices is simplified.
PRIORITY ENCODER
4 LINE BCD
TO µP
74LS147
VCC
ENSURING A VALID RESET OUTPUT DOWN TO V CC = 0 V
When VCC 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 kΩ resistor should be connected
from RESET to ground.
VCC
ADM809
OTHER SENSING
DEVICES
RESET
VCC
GND
VCC
Figure 4. Interfacing to µ Ps with Multiple Interrupts
ADM809-5S/L
RESET
3.3V
100nF
100k⍀
VCC
RESET
GND
ADM809-5S/L
47k⍀
47k⍀
GND
Figure 3. Ensuring a Valid RESET Output Down to
VCC = 0 V
THE BENEFITS OF A VERY ACCURATE RESET
THRESHOLD
Figure 5. Alternative Application Circuit with Extra
Decoupling
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.
3.3V
100nF
VCC
RESET
22k⍀
ADM809-5S/L
GND
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 sensors). The ADM809-5S/L can easily be integrated into existing
interrupt-handling circuits (Figure 6) or used as a stand-alone
device.
REV. 0
Figure 6. Additional Decoupling Can Be Achieved
Using a 100 nF Capacitor Between VCC and Ground
–5–
ADM809-5S/L
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
Surface Mount Package
RT-3
0.0550 (1.397)
0.0470 (1.194)
3
1
2
C00090–2.5–9/00 (rev. 0)
0.1200 (3.048)
0.1102 (2.799)
0.1040 (2.642)
0.0827 (2.101)
PIN 1
0.0236 (0.599)
0.0177 (0.450)
0.0413 (1.049)
0.0374 (0.950)
0.0807 (2.050)
0.0701 (1.781)
SEATING
PLANE
0.0210 (0.533)
0.0146 (0.371)
0.0100 (0.254)
0.0050 (0.127)
0.0059 (0.150)
0.0034 (0.086)
0.027 (0.686)
REF
PRINTED IN U.S.A.
0.0040 (0.102)
0.0005 (0.013)
0.0440 (1.118)
0.0320 (0.813)
–6–
REV. 0
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