PulseCore ASM705EUAF Low power î¼p supervisor circuit Datasheet

ASM705/706/707/708
ASM813L
April 2008
rev 1.6
Low Power µP Supervisor Circuits
General Description
Features
The ASM705 / 706 / 707 / 708 and ASM813L are cost
•
effective CMOS supervisor circuits that monitors powersupply and battery voltage level, and µP/µC operation.
• 4.40V threshold (ASM706/708)
•
The family offers several functional options. Each device
Precision power supply monitor
• 4.65V threshold (ASM705/707/813L)
•
generates a reset signal during power-up, power-down and
Debounced manual reset input
Voltage monitor
• 1.25V threshold
during brownout conditions. A reset is generated when
• Battery monitor / Auxiliary supply monitor
the supply drops below 4.65V (ASM705/707/813L) or
•
Watchdog timer (ASM705/706/813L)
4.40V (ASM706/708). For 3V power supply applications,
•
200ms reset pulse width
refer to the ASM705P/R/S/T data sheet. In addition, the
•
Active HIGH reset output (ASM707/708/813L)
ASM705/706/813L feature a 1.6 second watchdog timer.
•
MicroSO package
The ASM707/708 have both active-HIGH and active-LOW
reset outputs but no watchdog function. The ASM813L
Application
has the same pin-out and functions as the ASM705 but has
•
an active-HIGH reset output. A versatile power-fail circuit
•
Portable/Battery-operated systems
has a 1.25V threshold, useful in low battery detection and
•
Intelligent instruments
for monitoring non-5V supplies. All devices have a manual
•
Wireless communication systems
reset (MR) input. The watchdog timer output will trigger
•
•
•
PDAs and hend-held equipment
a reset if connected to MR.
Computers and embedded controllers
Automative Systems
Safety Systems
All devices are available in 8-pin DIP, SO and MicroSO
packages.
Typical Operating Circuit
PulseCore Semiconductor Corporation
1715 S. Bascom Ave Suite 200 Campbell, CA 95008 • Tel: 408-879-9077 • Fax: 408-879-9018
www.pulsecoresemi.com
Notice: The information in this document is subject to change without notice.
ASM705/706/707/708
ASM813L
April 2008
rev 1.6
Block Diagram
Pin Configuration
Low Power µP Supervisor Circuits
Notice: The information in this document is subject to change without notice.
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ASM705/706/707/708
ASM813L
April 2008
rev 1.6
Pin Description
Pin Number
ASM705/706
DIP/
SO
MicroSO
ASM707/708
DIP/
SO
MicroSO
ASM813L
DIP/
SO
Name
Function
MicroSO
1
3
1
3
1
3
MR
Manual reset input. The active LOW input
triggers a reset pulse. A 250 µA pull-up
current allows the pin to be driven by
TTL/CMOS logic or shorted to ground with a
switch.
2
4
2
4
2
4
VCC
+5V power supply input.
3
5
3
5
3
5
GND
Ground reference for all signals.
4
6
4
6
4
6
PFI
5
7
5
7
5
7
PFO
6
8
-
-
6
8
WDI
-
-
6
8
-
-
NC
7
1
7
1
-
-
8
2
-
-
8
2
WDO
-
-
8
2
7
1
RESET
RESET
Power-fail input voltage monitor. With PFI
less than 1.25V, PFO goes LOW. Connect
PFI to Ground or VCC when not in use.
Power-fail output. The output is active LOW
and sinks current when PFI is less than
1.25V.
Watchdog input. WDI controls the internal
watchdog timer. A HIGH or LOW signal for
1.6sec at WDI allows the internal timer to
run-out, setting WDO LOW. The watchdog
function is disabled by floating WDI or by
connecting WDI to a high impedance threestate buffer. The internal watchdog timer
clears when: RESET is asserted; WDI is
three-stated ; or WDI sees a rising or falling
edge.
Not Connected.
Active LOW reset output. Pulses LOW for
200ms when triggered, and stays LOW
whenever VCC is below the reset threshold.
RESET remains LOW for 200ms after VCC
rises above the reset threshold or MR goes
from LOW to HIGH. A watchdog timeout will
not trigger RESET unless WDO is
connected to MR.
Watchdog output. WDO goes LOW when
the 1.6 second internal watchdog timer
times-out and does not go HIGH until the
watchdog is cleared. In addition, when VCC
falls below the reset threshold, WDO goes
LOW. Unlike RESET, WDO does not have a
minimum pulse width and as soon as VCC
exceeds the reset threshold, WDO goes
HIGH with no delay.
Active HIGH reset output. The inverse of
RESET. The ASM813L only has a RESET
output.
Low Power µP Supervisor Circuits
Notice: The information in this document is subject to change without notice.
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ASM705/706/707/708
ASM813L
April 2008
rev 1.6
Detailed Description
A proper reset input enables a microprocessor /
microcontroller to start in a known state. ASM70X and
ASM813L assert reset to prevent code execution errors
during power-up, power-down and brown-out conditions.
RESET/RESET Timing
The RESET/RESET signals are designed to start a
µP/µC in a known state or return the system to a known
state.
The ASM707/708 have two reset outputs, one activeHIGH RESET and one active-LOW RESET output. The
ASM813L has only an active-HIGH output. RESET is
simply
the
complement
of
RESET.
Manual Reset (MR)
RESET is guaranteed to be LOW with VCC above 1.2V.
The active-LOW manual reset input is pulled high by a
During a power-up sequence, RESET remains low until
250µA pull-up current and can be driven low by
the supply rises above the threshold level, either 4.65V or
CMOS/TTL logic or a mechanical switch to ground. An
4.40V. RESET goes high approximately 200ms after
external debounce circuit is unnecessary since the
crossing the threshold.
140ms minimum reset time will debounce mechanical
pushbutton switches.
During power-down, RESET goes LOW as VCC falls
By connecting the watchdog output (WDO) and MR, a
below the threshold level and is guaranteed to be under
watchdog timeout forces RESET to be generated. The
0.4V with VCC above 1.2V.
ASM813L should be used when an active-HIGH RESET
In a brownout situation where VCC falls below the
is required.
threshold level, RESET pulses low. If a brown-out occurs
Watchdog Timer
during an already initiated reset, the pulse will continue
The watchdog timer available on the ASM705/706/813L
for a minimum of 140ms.
monitors µP/µC activity. An output line on the processor
is used to toggle the WDI line. If this line is not toggled
Power Failure Detection With Auxiliary Comparator
within 1.6 seconds, the internal timer puts the watchdog
All devices have an auxiliary comparator with 1.25V trip
output, WDO, into a LOW state. WDO will remain LOW
point and uncommitted output (PFO) and noninverting
until a toggle is detected at WDI.
input (PFI). This comparator can be used as a supply
If WDI is floated or connected to a three-stated circuit, the
voltage monitor with an external resistor voltage divider.
watchdog function is disabled, meaning, it is cleared and
The attenuated voltage at PFI should be set just below
not counting. The watchdog timer is also disabled if
the 1.25 threshold. As the supply level falls, PFI is
RESET is asserted. When RESET becomes inactive and
reduced causing the PFO output to transit LOW. Normally
the WDI input sees a high or low transition as short as
PFO interrupts the processor so the system can be shut
50ns, the watchdog timer will begin a 1.6 second
down in a controlled manner.
countdown. Additional transitions at WDI will reset the
watchdog timer and initiate a new countdown sequence.
Low Power µP Supervisor Circuits
Notice: The information in this document is subject to change without notice.
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ASM705/706/707/708
ASM813L
April 2008
rev 1.6
WDO will also become LOW and remain so, whenever
the supply voltage, VCC , falls below the device threshold
level. WDO goes HIGH as soon as VCC transitions above
the threshold. There is no minimum pulse width for WDO
as there is for the RESET outputs. If WDI is floated, WDO
essentially acts as a low-power output indicator.
Monitoring Voltages Other Than VCC
The ASM705-708 can monitor voltages other than VCC
using the Power Fail circuitry. If a resistive divider is
connected from the voltage to be monitored to the Power
Fail input (PFI), the PFO will go LOW if the voltage at PFI
goes below 1.25V reference. Should hysteresis be
desired, connect a resistor (equal to approximately 10
times the sum of the two resistors in the divider) between
the PFI and PFO pins. A capacitor between PFI and GND
Application Information
will reduce circuit sensitivity to input high-frequency
Ensuring That RESET is Valid Down to VCC = 0V
noise. If it is desired to assert a RESET for voltages other
When VCC falls below 1.1V, the ASM705-708 RESET
than VCC then the PFO output is to be connected to the
output no longer pulls down; it becomes indeterminate.
MR.
To avoid the possibility that stray charges build up and
force RESET to the wrong state, a pull-down resistor
should be connected to the RESET pin, thus draining
such charges to ground and holding RESET low. The
resistor value is not critical. A 100kΩ resistor will pull
RESET to ground without loading it.
Bi-directional Reset Pin Interfacing
The ASM705/6/7/8 can interface with µP/µC bi-directional
reset pins by connecting a 4.7kΩ resistor in series with
the RESET output and the µP/µC bi-directional RESET
pin.
Low Power µP Supervisor Circuits
Notice: The information in this document is subject to change without notice.
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ASM705/706/707/708
ASM813L
April 2008
rev 1.6
Monitoring a Negative Voltage
The Power-Fail circuitry can also monitor a negative
supply rail. When the negative rail is OK, PFO will be
LOW, and when the negative rail is failing (not negative
enough), PFO goes HIGH (the opposite of when positive
voltages are monitored). To trigger a reset, these outputs
need to be inverted: adding the resistors and transistor as
shown achieves this. The RESET output will then have
the same sense as for positive voltages: good = HIGH,
bad = LOW. It should be noted that this circuit’s accuracy
depends on the VCC line, the PFI threshold tolerance, and
the resistors.
Low Power µP Supervisor Circuits
Notice: The information in this document is subject to change without notice.
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ASM705/706/707/708
ASM813L
April 2008
rev 1.6
Absolute Maximum Ratings
Parameter
Min
Max
Unit
Pin Terminal Voltage with Respect to Ground
VCC
-0.3
6.0
V
All other inputs1
-0.3
VCC + 0.3
V
20
mA
Output Current: All outputs
20
mA
Rate of Rise at VCC
100
V/µs
Plastic DIP Power Dissipation
(Derate 9mW/°C above 70°C)
700
mV
470
mW
330
mW
Input Current at VCC and GND
SO Power Dissipation
(Derate 5.9mW/°C above 70°C)
MicroSO Power Dissipation
(Derate 4.1mW/°C above 70°C)
Operating Temperature Range
ASM705E/706E/707E/708E/813LE
-40
+85
°C
ASM705C/706C/707C/708C/813LC
0
70
°C
-65
160
°C
300
°C
2
200
KV
V
Storage Temperature Range
Lead Temperature (Soldering 10sec)
ESD rating
HBM
MM
Note:
1. The input voltage limits of PFI and MR can be exceeded if the input current is less than 10mA.
These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may affect
device reliability.
Low Power µP Supervisor Circuits
Notice: The information in this document is subject to change without notice.
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ASM705/706/707/708
ASM813L
April 2008
rev 1.6
Electrical Characteristics
Unless otherwise noted, specifications are over the operating temperature range and VCC supply voltages are 2.7V to 5.5V
(ASM706P,ASM708R), 3.0 V to 5.5V (ASM706/708S), 3.15V to 5.5V (ASM706/708T) and 4.1V to 5.5.V (ASM706/708J)
Parameter
Operating Voltage Range
SYMBOL
VCC
Supply Current
ICC
RESET Threshold
VRT
RESET Threshold
Hysteresis
RESET Pulse Width
MR Pulse Width
MR to RESET Out Delay
MR Input Threshold
MR Pullup current
tRS
tMD
VIH
VIL
Max
75
75
50
50
4.65
4.40
5.5
5.5
5.5
140
140
140
140
4.75
4.50
40
140
0.25
VIL = 0.4V, VIH=0.8VCC,
50
3.5
VOH
VOL
ASM705/706/813L, VCC = 5V
ISOURCE = 800µA
ISINK = 3.2mA
V
ms
250
0.8
600
µs
V
µA
0.4
0.3
V
0.4
0.4
V
2.25
S
0.9
tWP
VIH
VIL
ASM705/6/813L, WDI = VCC
ASM705/6/813L, WDI = 0V
ASM705/6/813L, ISOURCE =
800µA
ASM705/6/813L, ISINK =
1.2mA
VCC = 5V
µA
VCC - 1.5
1.00
PFI Input Threshold
PFI Input Current
280
2.0
100
VCC - 1.5
V
µs
Note 1
ASM705/6/813L
VOH
200
Unit
mV
0.15
tWD
VOL
PFO Output Voltage
4.50
4.25
Note 1
MR = 0V
ISOURCE = 800µA
ISINK = 3.2mA
ASM705/6/7/8, VCC = 1.2V,
ISINK = 100µA
ASM707/8/813L, ISOURCE =
800µA
ASM707/8, ISINK = 1.2mA
ASM813L, ISINK =3.2mA
ASM813L, VCC = 1.2V,
ISOURCE = 4µA
WDI Input Current
WDO Output Voltage
TYP
1.2
1.1
1.2
tMR
RESET Output Voltage
WDI Input Threshold
Min
Note 1
RESET Output Voltage
Watchdog Timeout
Period
WDI Pulse Width
Test Conditions
ASM705/6/7/8C
ASM813L
ASM705/6/7/8E, ASM813E
ASM705/706C/813LC
ASM705E/706E/813LE
ASM707C/708C
ASM707E/708E
ASM705/707/813L, Note 1
ASM706/708 Note 1
-150
1.60
ns
50
-50
0.8
150
V
µA
VCC - 1.5
V
0.4
1.2
-25
VCC - 1.5
1.25
0.01
1.3
25
0.4
V
nA
V
Notes 1: RESET (ASM705/6/7/8), RESET(ASM707/8, ASM813L)
Low Power µP Supervisor Circuits
Notice: The information in this document is subject to change without notice.
8 of 15
ASM705/706/707/708
ASM813L
April 2008
rev 1.6
Package Dimensions
8-Pin MicroSO
Low Power µP Supervisor Circuits
Notice: The information in this document is subject to change without notice.
9 of 15
ASM705/706/707/708
ASM813L
April 2008
rev 1.6
Package Dimensions (contd)
Plastic DIP (8-Pin)
Low Power µP Supervisor Circuits
Notice: The information in this document is subject to change without notice.
10 of 15
ASM705/706/707/708
ASM813L
April 2008
rev 1.6
Package Dimensions (contd)
SO (8-Pin)
Low Power µP Supervisor Circuits
Notice: The information in this document is subject to change without notice.
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ASM705/706/707/708
ASM813L
April 2008
rev 1.6
Ordering Codes
Part Number
Reset Threshold
Temperature
Pins-Package
Package
Marking
TIN - LEAD DEVICES
ASM705 Active LOW Reset, Watchdog Output And Manual RESET
ASM705CPA
4.65
0°C to +70 °C
8-Plastic DIP
ASM705CPA
ASM705CSA
4.65
0°C to +70 °C
8-SO
ASM705CSA
ASM705CUA
4.65
0°C to +70 °C
8-MicroSO
ASM705CUA
ASM705EPA
4.65
-40°C to +85°C
8-Plastic DIP
ASM705EPA
ASM705ESA
4.65
-40°C to +85°C
8-SO
ASM705ESA
ASM705EUA
4.65
-40°C to +85°C
8-MicroSO
ASM705EUA
8-Plastic DIP
ASM706CPA
ASM706 Active LOW Reset, Watchdog Output And Manual RESET
ASM706CPA
4.40
0°C to +70 °C
ASM706CSA
4.40
0°C to +70 °C
8-SO
ASM706CSA
ASM706CUA
4.40
0°C to +70 °C
8-MicroSO
ASM706CUA
ASM706EPA
4.40
-40°C to +85°C
8-Plastic DIP
ASM706EPA
ASM706ESA
4.40
-40°C to +85°C
8-SO
ASM706ESA
ASM707 Active LOW & HIGH Reset with Manual RESET
ASM707CPA
4.65
0°C to +70 °C
8-Plastic DIP
ASM707CPA
ASM707CSA
4.65
0°C to +70 °C
8-SO
ASM707CSA
ASM707CUA
4.65
0°C to +70 °C
8-MicroSO
ASM707CUA
ASM707EPA
4.65
-40°C to +85°C
8-Plastic DIP
ASM707EPA
ASM707ESA
4.65
-40°C to +85°C
8-SO
ASM707ESA
8-Plastic DIP
ASM708CPA
ASM708Active LOW & HIGH Reset with Manual RESET
ASM708CPA
4.40
0°C to +70 °C
ASM708CSA
4.40
0°C to +70 °C
8-SO
ASM708CSA
ASM708CUA
4.40
0°C to +70 °C
8-MicroSO
ASM708CUA
ASM708EPA
4.40
-40°C to +85°C
8-Plastic DIP
ASM708EPA
ASM708ESA
4.40
-40°C to +85°C
8-SO
ASM708ESA
ASM813L Active HIGH Reset, Watchdog Output And Manual RESET
ASM813LCPA
4.65
0°C to +70 °C
8-Plastic DIP
ASM813LCPA
ASM813LCSA
4.65
0°C to +70 °C
8-SO
ASM813LCSA
ASM813LCUA
4.65
0°C to +70 °C
8-MicroSO
ASM813LCUA
ASM813LEPA
4.65
-40°C to +85°C
8-Plastic DIP
ASM813LEPA
ASM813LESA
4.65
-40°C to +85°C
8-SO
ASM813LESA
Low Power µP Supervisor Circuits
Notice: The information in this document is subject to change without notice.
12 of 15
ASM705/706/707/708
ASM813L
April 2008
rev 1.6
Ordering Codes
Part Number
Reset Threshold
Temperature
Pins-Package
Package
Marking
LEAD FREE DEVICES
ASM705 Active LOW Reset, Watchdog Output And Manual RESET
ASM705CPAF
4.65
0°C to +70 °C
8-Plastic DIP
ASM705CPAF
ASM705CSAF
4.65
0°C to +70 °C
8-SO
ASM705CSAF
ASM705CUAF
4.65
0°C to +70 °C
8-MicroSO
ASM705CUAF
ASM705EPAF
4.65
-40°C to +85°C
8-Plastic DIP
ASM705EPAF
ASM705ESAF
4.65
-40°C to +85°C
8-SO
ASM705ESAF
ASM705EUAF
4.65
-40°C to +85°C
8-MicroSO
ASM705EUAF
8-Plastic DIP
ASM706CPAF
ASM706 Active LOW Reset, Watchdog Output And Manual RESET
ASM706CPAF
4.40
0°C to +70 °C
ASM706CSAF
4.40
0°C to +70 °C
8-SO
ASM706CSAF
ASM706CUAF
4.40
0°C to +70 °C
8-MicroSO
ASM706CUAF
ASM706EPAF
4.40
-40°C to +85°C
8-Plastic DIP
ASM706EPAF
ASM706ESAF
4.40
-40°C to +85°C
8-SO
ASM706ESAF
ASM707 Active LOW & HIGH Reset with Manual RESET
ASM707CPAF
4.65
0°C to +70 °C
8-Plastic DIP
ASM707CPAF
ASM707CSAF
4.65
0°C to +70 °C
8-SO
ASM707CSAF
ASM707CUAF
4.65
0°C to +70 °C
8-MicroSO
ASM707CUAF
ASM707EPAF
4.65
-40°C to +85°C
8-Plastic DIP
ASM707EPAF
ASM707ESAF
4.65
-40°C to +85°C
8-SO
ASM707ESAF
8-Plastic DIP
ASM708CPAF
ASM708Active LOW & HIGH Reset with Manual RESET
ASM708CPAF
4.40
0°C to +70 °C
ASM708CSAF
4.40
0°C to +70 °C
8-SO
ASM708CSAF
ASM708CUAF
4.40
0°C to +70 °C
8-MicroSO
ASM708CUAF
ASM708EPAF
4.40
-40°C to +85°C
8-Plastic DIP
ASM708EPAF
ASM708ESAF
4.40
-40°C to +85°C
8-SO
ASM708ESAF
ASM813L Active HIGH Reset, Watchdog Output And Manual RESET
ASM813LCPAF
4.65
0°C to +70 °C
8-Plastic DIP
ASM813LCPAF
ASM813LCSAF
4.65
0°C to +70 °C
8-SO
ASM813LCSAF
ASM813LCUAF
4.65
0°C to +70 °C
8-MicroSO
ASM813LCUAF
ASM813LEPAF
4.65
-40°C to +85°C
8-Plastic DIP
ASM813LEPAF
ASM813LESAF
4.65
-40°C to +85°C
8-SO
ASM813LESAF
Note:
For parts to be packed in Tape and Reel, add “-T” at the end of the part number.
Low Power µP Supervisor Circuits
Notice: The information in this document is subject to change without notice.
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ASM705/706/707/708
ASM813L
April 2008
rev 1.6
Feature Summary
ASM705
ASM706
ASM707
ASM708
ASM813L
Brownout detection
♦
♦
♦
♦
♦
♦
♦
♦
♦
♦
Manual RESET input
♦
♦
♦
♦
♦
Power-up/down RESET
♦
♦
♦
♦
♦
Watchdog Timer
♦
♦
Power fail detector
Active HIGH RESET output
Active LOW RESET output
RESET Threshold (V)
♦
♦
♦
♦
♦
♦
♦
4.65
4.40
4.65
4.40
Low Power µP Supervisor Circuits
Notice: The information in this document is subject to change without notice.
♦
4.65
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ASM705/706/707/708
ASM813L
April 2008
rev 1.6
PulseCore Semiconductor Corporation
1715 S. Bascom Ave Suite 200
Campbell, CA 95008
Tel: 408-879-9077
Fax: 408-879-9018
www.pulsecoresemi.com
Copyright © PulseCore Semiconductor
All Rights Reserved
Part Number: ASM705 / 706 / 707 / 708
ASM813L
Document Version: 1.6
© Copyright 2006 PulseCore Semiconductor Corporation. All rights reserved. Our logo and name are trademarks or registered trademarks
of PulseCore Semiconductor. All other brand and product names may be the trademarks of their respective companies. PulseCore reserves
the right to make changes to this document and its products at any time without notice. PulseCore assumes no responsibility for any errors
that may appear in this document. The data contained herein represents PulseCore’s best data and/or estimates at the time of issuance.
PulseCore reserves the right to change or correct this data at any time, without notice. If the product described herein is under development,
significant changes to these specifications are possible. The information in this product data sheet is intended to be general descriptive
information for potential customers and users, and is not intended to operate as, or provide, any guarantee or warrantee to any user or
customer. PulseCore does not assume any responsibility or liability arising out of the application or use of any product described herein, and
disclaims any express or implied warranties related to the sale and/or use of PulseCore products including liability or warranties related to
fitness for a particular purpose, merchantability, or infringement of any intellectual property rights, except as express agreed to in
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does not authorize its products for use as critical components in life-supporting systems where a malfunction or failure may reasonably be
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Low Power µP Supervisor Circuits
Notice: The information in this document is subject to change without notice.
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