SGM706
Low-Cost, Microprocessor
Supervisory Circuit
GENERAL DESCRIPTION
The SGM706 microprocessor supervisory circuit reduces
the complexity and number of components required to
monitor
accuracy
power-supply
compared
to
and
monitor
microprocessor
or
discrete
activity. It significantly improves system reliability and
separate
ICs
components.
The SGM706 provides power-supply monitoring circuitry
that
generates
a
reset
output
during
power-up,
power-down and brownout conditions. The reset output
remains operational with V
CC
as low as 1V. Independent
watchdog monitoring circuitry is also provided. This is
activated if the watchdog input has not been toggled
within 1.6 seconds.
In addition, there is a 1.25V threshold detector for
power-fail warning, low-battery detection, or monitoring
an additional power supply. An active-low manual-reset
input (
MR
) is also included.
The SGM706 is available in Green SOIC-8 package. It
operates over an ambient temperature range of -40℃ to
+85℃.
FEATURES
Precision Supply-Voltage Monitor
4.65V for SGM706-L
4.40V for SGM706-M
4.0V for SGM706-J
3.08V for SGM706-T
2.93V for SGM706-S
2.63V for SGM706-R
Guaranteed
RESET
Valid at V
CC
= 1V
200ms Reset Pulse Width
Debounced TTL/CMOS-Compatible
Manual-Reset Input
Independent Watchdog Timer (1.6sec) Timeout
Voltage Monitor for Power-Fail or Low-Battery Warning
-40℃ to +85℃ Operating Temperature Range
Green SOIC-8 Package
APPLICATIONS
Computers
Controllers
Intelligent Instruments
Automotive Systems
Critical
μP
Power Monitoring
SG Micro Corp
www.sg-micro.com
REV. A. 2
SGM706
PACKAGE/ORDERING INFORMATION
MODEL
RESET
THRESHOLD (V)
4.65
4.40
SGM706
4.0
3.08
2.93
2.63
PACKAGE
DESCRIPTION
SOIC-8
SOIC-8
SOIC-8
SOIC-8
SOIC-8
SOIC-8
ORDERING
NUMBER
SGM706-LYS8G/TR
SGM706-MYS8G/TR
SGM706-JYS8G/TR
SGM706-TYS8G/TR
SGM706-SYS8G/TR
SGM706-RYS8G/TR
Low-Cost, Microprocessor
Supervisory Circuit
PACKAGE
MARKING
SGM706-LYS8
SGM706-MYS8
SGM706-JYS8
SGM706-TYS8
SGM706-SYS8
SGM706-RYS8
PACKAGE
OPTION
Tape and Reel, 2500
Tape and Reel, 2500
Tape and Reel, 2500
Tape and Reel, 2500
Tape and Reel, 2500
Tape and Reel, 2500
NOTE: Order number is defined as the follow:
ABSOLUTE MAXIMUM RATINGS
(Typical values are at T
A
= +25℃, unless otherwise noted.)
Terminal Voltage (with respect to GND)
V
CC
....................................................................... -0.3V to 6.0V
All Other Inputs........................................ -0.3V to (V
CC
+ 0.3V)
Input Current, V
CC
..............................................................20mA
GND................................................................................. 20mA
Output Current, (all outputs).............................................. 20mA
Operating Temperature Range........................... -40℃ to +85℃
Junction Temperature....................................................... 150℃
Storage Temperature........................................ -65℃ to +150℃
Lead Temperature (Soldering, 10sec).............................. 260℃
ESD Susceptibility
HBM..................................................................................4000V
MM......................................................................................300V
ORDER NUMBER
SGM 706- X Y X G / TR
Tape and Reel
Green product
Package Type
S8
Y
SOIC-8
-40℃ to +85℃
Operating Temperature Range
RESET THRESHOLD
L: 4.65V
M:4.40V
J: 4.0V
T: 3.08V
S: 2.93V
R: 2.63V
CAUTION
This integrated circuit can be damaged by ESD if you don’t pay
attention to ESD protection. SGMICRO recommends that all
integrated circuits be handled with appropriate precautions.
Failure to observe proper handling and installation procedures
can cause damage. ESD damage can range from subtle
performance degradation to complete device failure. Precision
integrated circuits may be more susceptible to damage because
very small parametric changes could cause the device not to
meet its published specifications.
SGMICRO reserves the right to make any change in circuit
design, specification or other related things if necessary without
notice at any time. Please contact SGMICRO sales office to get
the latest datasheet.
NOTE:
Stresses beyond those listed under “Absolute Maximum
Ratings” may cause permanent damage to the device. These
are stress ratings only, and functional operation of the device at
these or any other conditions beyond those indicated in the
operational sections of the specifications is not implied.
Exposure to absolute maximum rating conditions for extended
periods may affect device reliability.
SG Micro Corp
www.sg-micro.com
2
SGM706
TYPICAL OPERATION CIRCUIT
UNREGULATED DC
+5V DC LINEAR
REGULATOR
Low-Cost, Microprocessor
Supervisory Circuit
MICROPROCESSOR
V
CC
V
CC
PFI
MR
PUSHBUTTON
SWITCH
RESET
RESET
I/O LINE
NMI
INTERRUPT
SGM706
WDI
WDO
PFO
SG Micro Corp
www.sg-micro.com
3
SGM706
PIN CONFIGURATION
(TOP VIEW)
MR
V
CC
GND
PFI
1
2
3
4
SOIC-8
8
Low-Cost, Microprocessor
Supervisory Circuit
WDO
RESET
WDI
PFO
SGM706
7
6
5
PIN DESCRIPTION
PIN
1
2
3
4
NAME
MR
FUNCTION
Manual-Reset Input triggers a reset pulse when pulled below 0.8V. This active-low input has an
internal 250μA (V
CC
= +5V) pull-up current. It can be driven from a TTL or CMOS logic line as well as
shorted to ground with a switch.
Power Supply Voltage that is monitored.
0V Ground Reference for all signals.
Power-Fail Voltage Monitor Input. When PFI is less than 1.25V,
PFO
goes low. Connect PFI to GND
or V
CC
when not used.
Power-Fail Output goes low and sinks current when PFI is less than 1.25V; otherwise
PFO
stays
high.
Watchdog Input. If WDI remains high or low for 1.6sec, the internal watchdog timer runs out and WDO
goes low (BLOCK DIAGRAM). Floating WDI or connecting WDI to a high-impedance three-state
buffer disables the watchdog feature. The internal watchdog timer clears whenever reset is asserted,
WDI is three-stated, or WDI sees a rising or falling edge.
Active-Low Reset Output pulses low for 200ms when triggered, and stays low whenever V
CC
is below
the reset threshold (4.65V for SGM706-L, 4.4V for SGM706-M, 4.0V for SGM706-J, 3.08V for
SGM706-T and 2.93V for SGM706-S, 2.63V for SGM706-R). It remains low for 200ms after V
CC
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 pulls low when the internal watchdog timer finishes its 1.6sec count and does not
go high again until the watchdog is cleared.
WDO
also goes low during low-line conditions.
Whenever V
CC
is below the reset threshold,
WDO
stays low; however, unlike
RESET
,
WDO
does
not have a minimum pulse width. As soon as V
CC
rises above the reset threshold,
WDO
goes high
with no delay.
V
CC
GND
PFI
5
PFO
6
WDI
7
RESET
8
WDO
SG Micro Corp
www.sg-micro.com
4
SGM706
Low-Cost, Microprocessor
Supervisory Circuit
ELECTRICAL CHARACTERISTICS
(V
CC
= 4.75V to 5.5V for SGM706-L; V
CC
= 4.5V to 5.5V for SGM706-M; V
CC
= 4.07V to 5.5V for SGM706-J; V
CC
= 3.14V to 5.5V for
SGM706-T; V
CC
= 2.95V to 5.5V for SGM706-S; V
CC
= 2.68V to 5.5V for SGM706-R; T
A
= -40°C to +85°C, unless otherwise noted.)
PARAMETER
Operating Voltage Range (V
CC
)
Supply Current (I
SUPPLY
)
SGM706-L
SGM706-M
Reset Threshold (V
RT
)
SGM706-J
SGM706-T
SGM706-S
SGM706-R
SGM706-L, SGM706-M
Reset Threshold Hysteresis
SGM706-J
SGM706-T, SGM706-S
SGM706-R
Reset Pulse Width (t
RS
)
I
SOURCE
= 800μA
RESET
Output Voltage
CONDITIONS
MIN
1.0
TYP
50
MAX
5.5
150
4.75
4.5
4.07
3.14
2.95
2.68
UNITS
V
μA
4.5
4.25
3.91
3.02
2.85
2.56
4.65
4.4
4.0
3.08
2.93
2.63
40
34
25
22
V
mV
120
V
CC
- 1.5
I
sink
= 3.2mA
V
CC
= 1V, I
sink
= 50μA
1.0
V
IL
= 0.4V, V
IH
= V
CC
Low
V
CC
= 5V
V
CC
= 5V
V
RST(MAX)
< V
CC
< 3.6V
V
RST(MAX)
< V
CC
< 3.6V
WDI = V
CC
WDI = 0V
I
SOURCE
= 800μA
I
sink
= 1.2mA
MR
= 0V
Low
High
200
280
0.4
0.3
ms
V
sec
ns
Watchdog Timeout Period (t
WD
)
WDI Pulse Width (t
WP
)
High
Low
High
WDI Input Current
WDO
Output Voltage
1.6
2.25
0.8
70
3.5
0.8
0.7 × V
CC
50
-150
V
CC
- 1.5
0.4
100
250
WDI Input Threshold
V
150
-50
μA
V
μA
ns
MR
Pull-Up Current
MR
Pulse Width (t
MR
)
600
0.8
MR
Input Threshold
T
A
= +25
℃
2
350
1.18
V
CC
- 1.5
0.4
1.25
0.2
1.3
V
ns
V
nA
V
MR
to Reset Out Delay (t
MD
)
PFI Input Threshold
PFI Input Current
PFO
Output Voltage
V
CC
= 5V
I
SOURCE
= 800μA
I
sink
= 3.2mA
SG Micro Corp
www.sg-micro.com
5
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