S P 7 0 6 R/ S / T - S P 7 0 8 R/ S / T
3.0V/3.3V Low Power Microprocessor Supervisory
Circuits
April 2015
Rev. 3.0.0
GENERAL DESCRIPTION
The SP706R/S/T and SP708R/S/T series is a
family of microprocessor (µP) supervisory
circuits that integrate myriad components
involved in discrete solutions which monitor
power-supply and battery in µP and digital
systems.
The SP706R/S/T and SP708R/S/T series will
significantly improve system reliability and
operational efficiency when compared to
solutions obtained with discrete components.
The features of the SP706R/S/T and
SP708R/S/T series include a watchdog timer, a
µP reset, a Power Fail Comparator, and a
manual-reset input.
The SP706R/S/T and SP708R/S/T series is ideal
for 3.0V or 3.3V applications in automotive
systems, computers, controllers, and intelligent
instruments. The SP706R/S/T and SP708R/S/T
series is an ideal solution for systems in which
critical monitoring of the power supply to the µP
and related digital components is demanded.
APPLICATIONS
Processors & DSPs Based Systems
Industrial & Medical Instruments
FEATURES
Precision Low Voltage Monitor
SP706R/SP708R: +2.63V
SP706S/SP708S: +2.93V
SP706T/SP708T: +3.08V
200ms RESET Pulse Width
SP706R/S/T: Active Low
SP708R/S/T: Active High and Active Low
Independent Watchdog Timer
1.6s Timeout (SP706R/S/T)
Enable/Disable Function
40µA Maximum Supply Current
Debounced TTL/CMOS Manual Reset
Input
RESET
Asserted Down to V
CC
=1V
V
CC
Glitch Immunity
Voltage Monitor for Power Failure or
Low Battery Warning
8-Pin NSOIC and MSOP Packages
Pin Compatible with Industry
Standards 706R/S/T and 708R/S/T
Part Number
SP706R
SP706S
SP706T
SP708R
SP708S
SP708T
RESET Threshold
2.63V
2.93V
3.08V
2.63V
2.93V
3.08V
RESET Active
Low
Low
Low
Low and High
Low and High
Low and High
Manual RESET
Yes
Yes
Yes
Yes
Yes
Yes
Watchdog
Yes
Yes
Yes
No
No
No
PFI Accuracy
4%
4%
4%
4%
4%
4%
Exar Corporation
48720 Kato Road, Fremont CA 94538, USA
www.exar.com
Tel. +1 510 668-7000 – Fax. +1 510 668-7001
S P 7 0 6 R/ S / T - S P 7 0 8 R/ S / T
3.0V/3.3V Low Power Microprocessor Supervisory
Circuits
ABSOLUTE MAXIMUM RATINGS
These are stress ratings only and functional operation of
the device at these ratings or any other above those
indicated in the operation sections of the specifications
below is not implied. Exposure to absolute maximum rating
conditions for extended periods of time may affect
reliability.
V
CC
.......................................................... -0.3V to 6.0V
All Other Inputs (Note 1) ................... -0.3V to (V
CC
+0.3V)
Input Current
VCC .................................................................20mA
GND ................................................................20mA
Output Current (All outputs) ...............................20mA
ESD Rating (HBM - Human Body Model) .................... 2kV
Continuous Power Dissipation
SO (derate 5.88mW/°C above +70°C)...............471mW
Mini SO (derate 4.10mW/°C above +70°C) ........330mW
Storage Temperature ..............................-65°C to 160°C
Lead Temperature (Soldering, 10 sec) ....................300°C
ELECTRICAL SPECIFICATIONS
Unless otherwise indicated, V
CC
= 2.7V to 5.5V (SP70xR), V
CC
= 3.15V to 5.5V (SP70xS), V
CC
= 3.0V to 5.5V (SP70xT), T
A
=
T
MIN
to T
MAX
, typical at 25°C.
Parameter
Operating Voltage Range V
CC
Supply Current I
SUPPLY
Min.
1.0
Typ.
Max.
5.5
Units
V
µA
µA
V
mV
Conditions
MR=V
CC
or floating, WDI floating,
V
CC
= 3.3V
MR=V
CC
or floating, V
CC
= 5.5V
SP706R. SP708R
SP706S. SP708S
SP706T. SP708T
Note 2
Note 2
V
RST(MAX)
<V
CC
<3.6V, I
SOURCE
=500µA
25
40
2.55
2.63
2.93
3.08
20
140
0.8xV
CC
200
40
80
2.70
3.00
3.15
280
Reset Threshold
Reset Threshold Hysteresis
Reset Pulse Width t
RS
RESET
Output Voltage
V
OH
V
OL
V
OH
V
OL
RESET Output Voltage
V
OH
V
OL
V
OH
V
OL
Watchdog Timeout Period t
WD
WDI Pulse Width t
WP
(note 1)
WDI Input Threshold
V
IL
V
IH
V
IL
V
IH
WDI Input Current
WDO
Output Voltage
V
IL
V
IH
V
IL
2.85
3.00
ms
0.3
V
CC
-1.5
0.4
V
CC
-0.6
0.3
V
CC
-1.5
0.4
1.00
50
0.6
0.7xV
CC
0.8
3.5
-1
0.8xV
CC
0.3
V
CC
-1.5
0.02
1
1.60
2.25
V
V
RST(MAX)
<V
CC
<3.6V, I
SINK
=1.2mA
4.5V<V
CC
<5.5V, I
SOURCE
=800µA
4.5V<V
CC
<5.5V, I
SINK
=3.2mA
V
RST(MAX)
<V
CC
<3.6V, I
SOURCE
=215µA
V
V
RST(MAX)
<V
CC
<3.6V, I
SOURCE
=1.2mA
4.5V<V
CC
<5.5V, I
SOURCE
=800µA
4.5V<V
CC
<5.5V, I
SOURCE
=3.2mA
s
ns
V
CC
<3.6V
V
IL
=0.4V, V
IH
=0.8xV
CC
V
RST(MAX)
<V
CC
<3.6V
V
V
RST(MAX)
<V
CC
<3.6V
V
CC
=5V
V
CC
=5V
µA
WDI=0V or WDI=V
CC
V
RST(MAX)
<V
CC
<3.6V, I
SOURCE
=500µA
V
RST(MAX)
<V
CC
<3.6V, I
SINK
=1.2mA
4.5V<V
CC
<5.5V, I
SOURCE
=800µA
V
© 2015 Exar Corporation
2/17
Rev. 3.0.0
S P 7 0 6 R/ S / T - S P 7 0 8 R/ S / T
3.0V/3.3V Low Power Microprocessor Supervisory
Circuits
Parameter
V
IH
MR
Pull-up Current
MR
Pulse Width t
MR
MR
Input Threshold
V
IL
V
IH
V
IL
V
IH
MR
to Reset Out Delay t
MD
PFI Input Threshold
PFI Input Current
PFO
Output Voltage
V
IL
V
IH
V
IL
V
IH
Note 1:WDI minimum rise /fall time is 1µs.
V
CC
-1.5
0.4
0.8xV
CC
0.3
V
V
RST(MAX)
<V
CC
<3.6V, I
SOURCE
=500µA
V
RST(MAX)
<V
CC
<3.6V, I
SINK
=1.2mA
4.5V<V
CC
<5.5V, I
SOURCE
=800µA
4.5V<V
CC
<5.5V, I
SINK
=3.2mA
1.20
-200.00
1.25
0.01
2.0
750
250
1.30
200.00
ns
V
nA
0.7xV
CC
0.8
0.6
V
V
RST(MAX)
<V
CC
<3.6V
V
RST(MAX)
<V
CC
<3.6V
4.5V<V
CC
<5.5V
4.5V<V
CC
<5.5V
V
RST(MAX)
<V
CC
<3.6V
4.5V<V
CC
<5.5V
V
CC
=3.0V - SP70xR, PFI falling
V
CC
=3.3V - SP70xS/T, PFI falling
V
PFI
= 1.36V
25
100
500
150
70
250
Min.
Typ.
Max.
0.4
250
600
µA
ns
Units
Conditions
4.5V<V
CC
<5.5V, I
SINK
=3.2mA
MR
= 0V, V
RST(MAX)
<V
CC
<3.6V
MR
= 0V, 4.5V<V
CC
<5.5V
V
RST(MAX)
<V
CC
<3.6V
4.5V<V
CC
<5.5V
BLOCK DIAGRAM
Fig. 1: SP706R/S/T Block Diagram
© 2015 Exar Corporation
3/17
Rev. 3.0.0
S P 7 0 6 R/ S / T - S P 7 0 8 R/ S / T
3.0V/3.3V Low Power Microprocessor Supervisory
Circuits
Fig. 2: SP708R/S/T Block Diagram
PIN ASSIGNMENT
Fig. 3: Pin Assignment
© 2015 Exar Corporation
4/17
Rev. 3.0.0
S P 7 0 6 R/ S / T - S P 7 0 8 R/ S / T
3.0V/3.3V Low Power Microprocessor Supervisory
Circuits
PIN DESCRIPTION
Name
Pin Number
SP706R/S/T
SOIC
MSOP
SP708R/S/T
SOIC
MSOP
Description
Manual Reset
This input triggers a reset pulse when pulled below 0.8V. This active
LOW input has an internal 70µA pull-up current. It can be driven
from a TTL or CMOS logic line or shorted to ground with a switch.
Voltage Input
Ground reference for all signals
Power-Fail Input
When this voltage monitor input is less than 1.25V,
PFO
goes LOW.
Connect PFI to ground or V
CC
when not in use.
Power-Fail Output
This output is LOW until PFI is less then 1.25V
Watchdog Input
If this input remains HIGH or LOW for 1.6s, the internal watchdog
timer times out and
WDO
goes LOW. Floating WDI or connecting WDI
to a high-impedance tri-state buffer disables the watchdog feature.
The internal watchdog timer clears whenever
RESET
is asserted, WDI
is tri-stated, or whenever WDI sees a rising or falling edge.
No Connect
Active-LOW
RESET
Output
This output pulses LOW for 200ms when triggered and stays LOW
whenever V
CC
is below the reset threshold. 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
This output pulls LOW when the internal watchdog timer finishes its
1.6s 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
is above
the reset threshold,
WDO
goes HIGH with no delay.
Active-HIGH RESET Output
This output is the complement of
RESET.
Whenever RESET is HIGH,
RESET
is LOW and vice-versa. Note that the SP708R/S/T has a reset
output only.
MR
V
CC
GND
PFI
PFO
1
2
3
4
5
3
4
5
6
7
1
2
3
4
5
3
4
5
6
7
WDI
6
8
-
-
N.C.
-
-
6
8
RESET
7
1
7
1
WDO
8
2
-
-
RESET
-
-
8
2
ORDERING INFORMATION
Part Number
SP706RCN-L
SP706RCN-L/TR
SP706RCU-L
SP706RCU-L/TR
SP706REN-L
SP706REN-L/TR
SP706REU-L
SP706REU-L/TR
SP706SCN-L
SP706SCN-L/TR
SP706SCU-L
SP706SCU-L/TR
Temperature
Range
0°C≤T
A
≤+70°C
0°C≤T
A
≤+70°C
0°C≤T
A
≤+70°C
0°C≤T
A
≤+70°C
-40°C≤T
A
≤+85°C
-40°C≤T
A
≤+85°C
-40°C≤T
A
≤+85°C
-40°C≤T
A
≤+85°C
0°C≤T
A
≤+70°C
0°C≤T
A
≤+70°C
0°C≤T
A
≤+70°C
0°C≤T
A
≤+70°C
Marking
SP706RC
YYWWL
X
706R
CXXX
YWW
SP706RE
YYWWL
X
706R
EXXX
YWW
SP706SC
YYWWL
X
706S
CXXX
YWW
Package
8-pin NSOIC
Packing
Quantity
Bulk
Note 1
Lead Free
Note 2
8-pin NSOIC 2.5K/Tape & Reel Lead Free
Bulk
8-pin MSOP
Lead Free
8-pin MSOP 2.5K/Tape & Reel Lead Free
Bulk
8-pin NSOIC
Lead Free
8-pin NSOIC 2.5K/Tape & Reel Lead Free
Bulk
8-pin MSOP
Lead Free
8-pin MSOP 2.5K/Tape & Reel Lead Free
Bulk
8-pin NSOIC
Lead Free
8-pin NSOIC 2.5K/Tape & Reel Lead Free
Bulk
8-pin MSOP
Lead Free
8-pin MSOP 2.5K/Tape & Reel Lead Free
© 2015 Exar Corporation
5/17
Rev. 3.0.0