SS811, SS812
Reset Circuits with Manual Reset Input
FEATURES
Ultra-low supply current of 1µA (typ.)
Guaranteed reset valid to Vcc=0.9V
Available in two output yypes:
Push-pull active -low (SS811)
Push-pull active -high (SS812)
Power-on reset pulse width minimum 140ms
Internally fixed threshold 2.3V, 2.6V, 2. 9V, 3.1V, 4.0V,
4.4V, and 4.6V
Tight voltage threshold tolerance: 1.5%
Low profile package: SOT-23-5
These devices perform as valid singles in applications
with Vcc ranging from 6.0V down to 0.9V. The reset
signal lasts for a minimum period of 140ms whenever the
V
CC
supply voltage falls below a preset threshold. Both
the SS811 and SS812 were designed with a reset
comparator to help identify invalid signals lasting less
than 140ms. The only difference between the SS811 and
the SS812 is that one has an active -low
RESET
output
and the other has an active -high RESET output .
DESCRIPTION
The SS811 and SS812 are low-power microprocessor
(µP ) supervisory circuits used to monitor power supplies
in µP and digital systems. They improve circuit reliability
and reduce cost by eliminating external components.
The SS811 and SS812 also offer a manual reset input.
APPLICATIONS
l
l
l
l
Notebook Computers
Digital Still Cameras
PDAs
Critical Microprocessor Monitoring
A low supply current (1µA) makes the SS811 and
SS812 ideal for portable equipment. The devices are
available in a SOT-23-5 package.
TYPICAL APPLICATION CIRCUIT
V
CC
VCC
SS811
(SS812)
RESET
MR (RESET)
GND
VCC
µP
RESET
INPUT
GND
Pushbutton
Switch
Rev.1.01 4/06/2004
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SS811, SS812
ABSOLUTE MAXIMUM RATINGS
V
CC
RESET,
RESET
Input Current (V
CC
,
MR
)
Output Current (RESET or
RESET
)
Continuous Power Dissipation (T
A
= +70°C)
Operating Junction Temperature Range
Storage Temperature Range
Lead Temperature (Soldering) 10 sec
-0.3V ~6.5V
-0.3V ~ (VCC+0.3V)
20mA
20mA
320mW
-40°C ~ 85°C
- 65°C ~ 150°C
260°C
Note1: Any stress beyond the Absolute Maximum Ratings above may cause permanent damage to the device.
TEST CIRCUIT
1
2
3
GND
VCC
NC
MR
RESET
SS811
5
4
Iin
Vin
Pushbutton
Switch
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SS811, SS812
ELECTRICAL CHARACTERISTICS
(Typical values are at T
A
=25° C, unless otherwise specified)
PARAMETER
Operating Voltage Range
Supply Current
TEST CONDITIONS
V
CC
= V
TH
+0.1V
SS811-23
SS811-26
SS811-29
Reset Threshold
V
TH
SS811-31
SS811-40
SS811-44
SS811-46
V
CC
to Reset Delay
Reset Active Timeout Period
T
RD
T
RP
T
MD
V
IH
V
IL
10
V
OH
V
OL
V
OH
V
OL
V
CC
=V
TH
+0.1V, I
SOURCE
=1mA
V
CC
=V
TH
- 0.1V, I
SINK
=1mA
V
CC
=V
TH
+0.1V, I
SOURCE
=1mA
V
CC
=V
TH
- 0.1V, I
SINK
=1mA
0.8V
CC
0.2Vcc
0.8V
CC
0.2Vcc
20
T
A
=+25°C
T
A
= -40°C to +85°C
T
A
=+25°C
T
A
= -40°C to +85°C
T
A
=+25°C
T
A
= -40°C to +85°C
T
A
=+25°C
T
A
= -40°C to +85°C
T
A
=+25°C
T
A
= -40°C to +85°C
T
A
=+25°C
T
A
= -40°C to +85°C
T
A
=+25°C
T
A
=-40°C to +85°C
T
A
=+25°C
2.265
2.254
2.561
2.548
2.857
2.842
3.054
3.038
3.940
3.920
4.334
4.312
4.531
4.508
20
140
100
0.5
0.7V
CC
0.25V
CC
30
230
560
1030
4.6
4.4
4.0
3.1
2.9
2.6
MIN.
0.9
1
2.3
TYP.
MAX.
6
3
2.335
2.346
2.639
2.652
2.944
2.958
3.147
3.162
4.060
4.080
4.466
4.488
4.669
4.692
µS
mS
µS
V
KΩ
V
V
V
UNIT
V
µA
SYMBOL
V
CC
I
CC
V
CC
=V
TH
to (V
TH
–0.1V), V
TH
=3.1V
V
CC
= V
TH(MAX)
T
A
= -40°C to +85°C
Vcc=6V
MR
to Reset Propagation
Delay
MR
Input Threshold
MR
Pull-Up Resistance
RESET
Output Voltage
RESET Output Voltage
Note2:
RESET
output is for the SS811; RESET output is for the SS812.
Note3: Specifications for operating temperature ranges from -40°C to 85°C, are guaranteed by Statistical Quality
Controls (SQC), with no production testing.
Rev.1.01 4/06/2004
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SS811, SS812
TYPICAL PERFORMANCE CHARACTERISTICS
1.5
1.4
120
Power -Down Reset Delay (µs )
110
100
90
80
70
60
50
40
30
20
10
0
-60
-40
-20
0
20
40
V
TH
=2.3V
Supply Current (µA)
1.3
1.2
1.1
1.0
0.9
0.8
0.7
0.6
0.5
-40
-
20
0
20
V
TH
=2.3V
V
O D
=V
TH
-V
CC
V
TH
=3.1V
V
TH
=4.6V
V
OD
=50mV
V
OD
=100mV
V
OD
=200mV
40
60
80
100
60
80
100
Temperature (
°
C)
Fig 1 Supply Current vs. Temperature
240
Temperature (
°
C)
Fig 2 Power-Down Reset Delay vs. Temperature
Power -Down Reset Delay (µs )
Power -Down Reset Delay (µs )
220
200
180
160
140
120
100
80
60
40
20
0
-
60
-
40
-20
V
TH
=3.1V
V
O D
=V
TH
-V
CC
400
V
OD
=50mV
V
TH
=4.6V
V
OD
=V
TH
-V
CC
300
V
OD
=50mV
200
V
OD
=100mV
100
V
OD
=100mV
V
OD
=200mV
0
20
40
60
80
100
V
OD
=200mV
0
-60
-
40
-
20
0
20
40
60
80
100
Temperature (
°
C)
Fig 3 Power-Down Reset Delay vs. Temperature
600
Temperature (
°
C)
Fig 4 Power-Down Reset Delay vs. Temperature
Normalized Reset Threshold (V)
1.010
1.005
1.000
0.995
0.990
0.985
-40
-20
0
V
TH
=4.6V
Power -Up Reset Timeout (ms)
1.015
500
400
V
TH
=3.1V
300
200
V
TH
=3.1V
V
TH
=4.6V
V
TH
=2.3V
V
TH
=2.3V
100
0
-60
20
40
60
80
100
-40
-20
0
20
40
60
80
100
Temperature (
°
C)
Fig 5 Normalized Reset Threshold vs. Temperature
Temperature (
°
C)
Fig 6 Power-Up Reset Timeout vs. Temperature
Rev.1.01 4/06/2004
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