SGM706
Low-Cost, Microprocessor
Supervisory Circuit
GENERAL DESCRIPTION
The
SGM706
microprocessor
FEATURES
supervisory
Precision Supply-Voltage Monitor
circuit
reduces the complexity and number of components
4.65V for SGM706-L
required
4.40V for SGM706-M
to
monitor
power-supply
and
monitor
microprocessor activity. It significantly improves system
4.0V for SGM706-J
reliability and accuracy compared to separate ICs or
3.08V for SGM706-T
discrete components.
2.93V for SGM706-S
The
SGM706
provides
power-supply
2.63V for SGM706-R
monitoring
Guaranteed RESET Valid at VCC = 1V
circuitry that generates a reset output during power-up,
200ms Reset Pulse Width
power-down and brownout conditions. The reset output
remains
operational
with
VCC
as
low
as
Debounced TTL/CMOS-Compatible
1V.
Manual-Reset Input
Independent watchdog monitoring circuitry is also
Independent Watchdog Timer (1.6sec) Timeout
provided. This is activated if the watchdog input has not
Voltage Monitor for Power-Fail or Low-Battery
been toggled within 1.6 seconds.
Warning
In addition, there is a 1.25V threshold detector for
-40℃ to +85℃ Operating Temperature Range
power-fail warning, low-battery detection, or monitoring
Available in Green SOIC-8 Package
an additional power supply. An active-low manual-reset
input ( MR ) is also included.
APPLICATIONS
The SGM706 is available in Green SOIC-8 package. It
operates over an ambient temperature range of -40℃
Computers
to +85℃.
Controllers
Intelligent Instruments
Automotive Systems
Critical μP Power Monitoring
TYPICAL OPERATION CIRCUIT
UNREGULATED DC
+5V DC LINEAR
REGULATOR
MICROPROCESSOR
VCC
VCC
PFI
MR
RESET
SGM706
WDI
WDO
PFO
RESET
I/O LINE
NMI
INTERRUPT
PUSHBUTTON
SWITCH
SG Micro Corp
www.sg-micro.com
MARCH 2017 – REV. A. 3
Low-Cost, Microprocessor
Supervisory Circuit
SGM706
PACKAGE/ORDERING INFORMATION
MODEL
SGM706
RESET
THRESHOLD (V)
PACKAGE
DESCRIPTION
ORDERING
NUMBER
4.65
SOIC-8
SGM706-LYS8G/TR
4.40
SOIC-8
SGM706-MYS8G/TR
4.0
SOIC-8
SGM706-JYS8G/TR
3.08
SOIC-8
SGM706-TYS8G/TR
2.93
SOIC-8
SGM706-SYS8G/TR
2.63
SOIC-8
SGM706-RYS8G/TR
PACKAGE
MARKING
SGM706-LYS8
XXXXX
SGM706-MYS8
XXXXX
SGM706-JYS8
XXXXX
SGM706-TYS8
XXXXX
SGM706-SYS8
XXXXX
SGM706-RYS8
XXXXX
PACKAGE
OPTION
Tape and Reel, 4000
Tape and Reel, 4000
Tape and Reel, 4000
Tape and Reel, 4000
Tape and Reel, 4000
Tape and Reel, 4000
NOTE: XXXXX = Date Code and Vendor Code.
Green (RoHS & HSF): SG Micro Corp defines "Green" to mean Pb-Free (RoHS compatible) and free of halogen substances. If
you have additional comments or questions, please contact your SGMICRO representative directly.
ABSOLUTE MAXIMUM RATINGS
ESD SENSITIVITY CAUTION
(Typical values are at TA = +25℃, unless otherwise noted.)
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.
Terminal Voltage (with respect to GND)
VCC .................................................................. -0.3V to 6.0V
All Other Inputs ...................................-0.3V to (VCC + 0.3V)
Input Current, VCC ........................................................ 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
DISCLAIMER
SG Micro Corp reserves the right to make any change in
circuit design, specification or other related things if necessary
without notice at any time.
OVERSTRESS CAUTION
Stresses beyond those listed may cause permanent damage
to the device. Functional operation of the device at these or
any other conditions beyond those indicated in the operational
section of the specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
reliability.
SG Micro Corp
www.sg-micro.com
MARCH 2017
2
Low-Cost, Microprocessor
Supervisory Circuit
SGM706
PIN CONFIGURATION
(TOP VIEW)
MR
1
VCC
2
GND
3
PFI
4
SGM706
8
WDO
7
RESET
6
WDI
5
PFO
SOIC-8
PIN DESCRIPTION
PIN
NAME
2
VCC
FUNCTION
Manual-Reset Input triggers a reset pulse when pulled below 0.8V. This active-low input has an internal
250μA (VCC = +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.
1
MR
3
GND
0V Ground Reference for all signals.
4
PFI
5
PFO
6
WDI
7
RESET
8
WDO
Power-Fail Voltage Monitor Input. When PFI is less than 1.25V, PFO goes low. Connect PFI to GND or VCC
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 VCC 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 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 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 VCC is below
the reset threshold, WDO stays low; however, unlike RESET , WDO does not have a minimum pulse
width. As soon as VCC rises above the reset threshold, WDO goes high with no delay.
SG Micro Corp
www.sg-micro.com
MARCH 2017
3
Low-Cost, Microprocessor
Supervisory Circuit
SGM706
ELECTRICAL CHARACTERISTICS
(VCC = 4.75V to 5.5V for SGM706-L; VCC = 4.5V to 5.5V for SGM706-M; VCC = 4.07V to 5.5V for SGM706-J; VCC = 3.14V to 5.5V
for SGM706-T; VCC = 2.95V to 5.5V for SGM706-S; VCC = 2.68V to 5.5V for SGM706-R; TA = -40°C to +85°C, unless otherwise
noted.)
PARAMETER
CONDITIONS
Operating Voltage Range (VCC)
MIN
Reset Threshold Hysteresis
5.5
V
50
150
μA
4.75
SGM706-L
4.5
4.65
SGM706-M
4.25
4.4
4.5
SGM706-J
3.91
4.0
4.07
SGM706-T
3.02
3.08
3.14
SGM706-S
2.85
2.93
2.95
SGM706-R
2.56
2.63
2.68
SGM706-L, SGM706-M
40
SGM706-J
34
SGM706-T, SGM706-S
25
SGM706-R
22
Reset Pulse Width (tRS)
120
ISOURCE = 800μA
RESET Output Voltage
MAX
1.0
Supply Current (ISUPPLY)
Reset Threshold (VRT)
TYP
200
VCC = 1V, Isink = 50μA
WDI Pulse Width (tWP)
WDI Input Threshold
Low
VCC = 5V
High
VCC = 5V
Low
VRST(MAX) < VCC < 3.6V
High
VRST(MAX) < VCC < 3.6V
WDI = 0V
ISOURCE = 800μA
WDO Output Voltage
MR = 0V
SG Micro Corp
www.sg-micro.com
V
2.25
Low
High
TA = +25℃
0.8
50
-150
150
-50
VCC - 1.5
0.4
100
600
0.8
2
1.18
Isink = 3.2mA
μA
V
μA
ns
1.25
1.3
0.2
ISOURCE = 800μA
V
0.7 × VCC
350
VCC = 5V
sec
0.8
3.5
PFI Input Current
PFO Output Voltage
0.4
ns
MR to Reset Out Delay (tMD)
PFI Input Threshold
ms
250
MR Pulse Width (tMR)
MR Input Threshold
1.6
Isink = 1.2mA
MR Pull-Up Current
280
70
WDI = VCC
WDI Input Current
mV
0.3
1.0
VIL = 0.4V, VIH = VCC
V
VCC - 1.5
Isink = 3.2mA
Watchdog Timeout Period (tWD)
UNITS
V
ns
V
nA
VCC - 1.5
0.4
V
MARCH 2017
4
Low-Cost, Microprocessor
Supervisory Circuit
SGM706
FUNCTIONAL BLOCK DIAGRAM
WDI
WATCHDOG
TRANSITION
DETECTOR
6
WATCHDOG
TIMER
VCC
MR
RESET
GENERATOR
VCC
2
7
RESET
+
_
4.65V for SGM706-L*
PFI
WDO
TIMEBASE FOR
RESET AND
WATCHDOG
250μA
1
8
4
SGM706
+
_
5
PFO
1.25V
* 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
SG Micro Corp
www.sg-micro.com
3
GND
MARCH 2017
5
Low-Cost, Microprocessor
Supervisory Circuit
SGM706
TYPICAL PERFORMANCE CHARACTERISTICS
VCC
VCC
VCC
RESET
GND
PFI
+
-
RESET
2kΩ
VCC
GND
RESET
330pF
10kΩ
RESET
30pF
+5V
PFO
30pF
+1.25V
+5V
1kΩ
PFI
+
PFO
-
30pF
1kΩ
+1.25V
SG Micro Corp
www.sg-micro.com
MARCH 2017
6
SGM706
Low-Cost, Microprocessor
Supervisory Circuit
TYPICAL PERFORMANCE CHARACTERISTICS
SG Micro Corp
www.sg-micro.com
MARCH 2017
7
Low-Cost, Microprocessor
Supervisory Circuit
SGM706
APPLICATION NOTES
Ensuring a Valid RESET Output Down to
VCC = 0V
When VCC falls below 1V, the SGM706 RESET output no
longer sinks current-it becomes an open circuit.
High-impedance CMOS logic inputs can drift to undetermined
voltages if left undriven. If a pull-down resistor is added to the
RESET pin as shown in Figure 1, any stray charge or
leakage currents will be drained to ground, holding RESET
low. Resistor value (R1) is not critical. It should be about
100kΩ, large enough not to load RESET and small enough
to pull RESET to ground.
Monitoring a Negative Voltage
The power-fail comparator can also monitor a negative supply
rail (Figure 3). When the negative rail is good (a negative
voltage of large magnitude), PFO is low, and when the
negative rail is degraded (a negative voltage of lesser
magnitude), PFO is high. By adding the resistors and
transistor as shown, a high PFO triggers reset. As long as
PFO remains high, the SGM706 will keep reset asserted
( RESET = low, RESET = high). Note that this circuit’s
accuracy depends on the PFI threshold tolerance, the VCC
line, and the resistors.
+5V
100kΩ
VCC
SGM706
MR
R1
SGM706
PFI
RESET
R1
PFO
100kΩ
RESET
R2
2N3904
TO μP
GND
V-
Figure 1. RESET Valid to Ground Circuit
Monitoring Voltages Other Than the
Unregulated DC Input
Monitor voltages other than the unregulated DC by
connecting a voltage divider to PFI and adjusting the ratio
appropriately. If required, add hysteresis by connecting a
resistor (with a value approximately 10 times the sum of the
two resistors in the potential divider network) between PFI
and PFO . A capacitor between PFI and GND will reduce the
power-fail circuit’s sensitivity to high-frequency noise on the
line being monitored. RESET can be asserted on other
voltages in addition to the +5V VCC line. Connect PFO to
MR to initiate a RESET pulse when PFI drops below 1.25V.
Figure 2 shows the SGM706 configured to assert RESET
when the +5V supply falls below the reset threshold, or when
the +12V supply falls below approximately 11V.
+12V +5V
MR
+5V
0V
+5V
PFO
0V
V-
VTRIP
0V
1.25 - VTRIP
5 – 1.25
=
R1
R2
VTRIP < 0
Figure 3. Monitoring a Negative Voltage
Interfacing to μPs with Bidirectional Reset
Pins
μPs with bidirectional reset pins, such as the Motorola
68HC11 series, can contend with the SGM706 RESET
output. If, for example, the RESET output is driven high and
the Microprocessor wants to pull it low, indeterminate logic
levels may result. To correct this, connect a 4.7kΩ resistor
between the RESET output and the μP reset I/O, as in
Figure 4. Buffer the RESET output to other system
components.
BUFFRED RESET TO OTHER SYSTEM COMPONENTS
VCC
1MΩ
1%
130kΩ
1%
RESET
SGM706
PFI
GND
TO μP
VCC
MR
PFO
Figure 2. Monitoring Both +5V and +12V
SG Micro Corp
www.sg-micro.com
VCC
Microprocessor
SGM706
RESET
GND
4.7kΩ
RESET
GND
Figure 4. Interfacing to Microprocessors with
Bidirectional Reset I/O
MARCH 2017
8
SGM706
Low-Cost, Microprocessor
Supervisory Circuit
REVISION HISTORY
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
MARCH 2017 ‒ REV.A.2 to REV.A.3
Changed Packing Option ..................................................................................................................................................................................... 2
JANUARY 2013 ‒ REV.A.1 to REV.A.2
Added Recommended Land Pattern Information ............................................................................................................................................... 10
Added Tape and Reel Information ............................................................................................................................................................... 11, 12
MAY 2011 ‒ REV.A to REV.A.1
Updated Package Description ........................................................................................................................................................................... All
Changes from Original (APRIL 2010) to REV.A
Changed from product preview to production data ............................................................................................................................................. All
SG Micro Corp
www.sg-micro.com
MARCH 2017
9
PACKAGE INFORMATION
PACKAGE OUTLINE DIMENSIONS
SOIC-8
0.6
D
e
2.2
E1
E
5.2
b
1.27
RECOMMENDED LAND PATTERN (Unit: mm)
L
A
A1
c
θ
A2
Symbol
Dimensions
In Millimeters
MIN
MAX
Dimensions
In Inches
MIN
MAX
A
1.350
1.750
0.053
0.069
A1
0.100
0.250
0.004
0.010
A2
1.350
1.550
0.053
0.061
b
0.330
0.510
0.013
0.020
c
0.170
0.250
0.006
0.010
D
4.700
5.100
0.185
0.200
E
3.800
4.000
0.150
0.157
E1
5.800
6.200
0.228
0.244
e
SG Micro Corp
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1.27 BSC
0.050 BSC
L
0.400
1.270
0.016
0.050
θ
0°
8°
0°
8°
TX00010.000
PACKAGE INFORMATION
TAPE AND REEL INFORMATION
REEL DIMENSIONS
TAPE DIMENSIONS
P2
W
P0
Q1
Q2
Q1
Q2
Q1
Q2
Q3
Q4
Q3
Q4
Q3
Q4
B0
Reel Diameter
K0
A0
P1
Reel Width (W1)
DIRECTION OF FEED
NOTE: The picture is only for reference. Please make the object as the standard.
KEY PARAMETER LIST OF TAPE AND REEL
Reel
Diameter
Reel Width
W1
(mm)
A0
(mm)
B0
(mm)
K0
(mm)
P0
(mm)
P1
(mm)
P2
(mm)
W
(mm)
Pin1
Quadrant
SOIC-8
13″
12.4
6.40
5.40
2.10
4.0
8.0
2.0
12.0
Q1
SG Micro Corp
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TX10000.000
DD0001
Package Type
PACKAGE INFORMATION
CARTON BOX DIMENSIONS
NOTE: The picture is only for reference. Please make the object as the standard.
KEY PARAMETER LIST OF CARTON BOX
Length
(mm)
Width
(mm)
Height
(mm)
Pizza/Carton
13″
386
280
370
5
SG Micro Corp
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DD0002
Reel Type
TX20000.000
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