UM809/810
3-Pin Microprocessor Reset Circuits
UM809/810 SC70-3/SOT23-3
General Description
The UM809/810 series are ultra low current, cost effective system supervisory circuits designed to
monitor the power supplies in digital systems. They provide a reset signal to the host processor
when necessary, offer excellent circuit reliability & low cost by eliminating external component
and adjustment when used with +5V, +3.3V, +3.0V or other voltage powered circuits.
The reset output is driven active within 10 µs of power supply falling through the reset voltage
threshold. Reset is keeping active for a minimum of 140ms after system power supply has risen
above the reset threshold. Reset threshold suitable for operation with variety of supply voltage are
available.
UM809 has an active-low reset output while UM810 has an active-high reset output. The UM809
/ 810 are optimized to reject fast transient glitches on the power supply line, and the reset output
are guaranteed to be in the correct logic state for power supply V
CC
down to 1V.
Each of these ICs consists of a voltage reference comparator, resistors for detector threshold
setting, delay generator, output driver & hysteresis circuit. The reset threshold & time delay are
fixed with high accuracy internally and does not require any external adjustment.
Low supply current of 3 µA (V
CC
=3V) makes UM809/810 ideal for low power application. Both
devices are available in 3 Pin SC70 or SOT23 packages.
Applications
CPU and logic circuit Reset
Power fail detector
Computers
Embedded system
Battery powered equipment
Intelligent instrument
Features
Wide operation voltage range of 1V to 10V
Typical Quiescent current of
3μA
No External components
3-Pin small SC70 and SOT23 packages
V
CC
Transient immunity
Correct logic output guaranteed to V
CC
=1.0V
Precision V
CC
monitor for 2.5V, 3.0V, 3.3V,
and 5.0V supplies
Available in 2 output configurations
Push-pull low active Reset output(UM809)
Push-pull high active Reset output(UM810)
Wide operation Temperature: -40
℃
to 105
℃
Pin Configurations
Top View
Top View
Top View
UM809/810
M: Monthly Code
SC70-3/SOT23-3
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UM809/810
Ordering Information
UM8 XX ZZ P
XX: Output Type
=09 Push-pull Active Low
=10 Push-pull Active High
ZZ: Reset Threshold (V)
P: Package Type
=S SOT23-3
=P SC70-3
Absolute Maximum Ratings (Note 1)
Symbol
V
CC
I
CC
I
O
Supply Voltage
RESET, RESET (push-pull)
Input Current, V
CC
Output Current, RESET, RESET
Rate of Rise, V
CC
Continuous Power Dissipation
Operating Junction Temperature
Storage Temperature Range
_____________
_____________
Parameter
Value
-0.3 to +10
-0.3 to V
CC
+0.3
20
20
SC70-3
SOT23-3
SC70-3
SOT23-3
100
174
320
-40 to +125
-40 to +105
-65 to +150
Unit
V
V
mA
mA
V/us
mW
°C
°C
P
D
T
J
T
STG
Lead Temperature (soldering, 10s)
300
°C
Note 1: 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 are not implied. Exposure
to absolute maximum rating conditions for extended periods may affect device reliability.
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UM809/810
Electrical Characteristics
V
CC
= full range, T
A
= -40°C to +105°C (SOT23) or T
A
= -40°C to +125°C (SC70), unless
otherwise noted. Typical values are at T
A
=+25°C, V
CC
= 5V for L/M/J versions, V
CC
= 3.3V for
T/S versions, V
CC
= 3V for R version, and V
CC
= 2.5V for Z version. (Note 1)
Symbol
Parameter
Conditions
T
A
=0
℃
to + 70
℃
V
CC
Range
T
A
=-40
℃
to + 105
℃
(SOT23 )
T
A
=-40
℃
to + 125
℃
(SC70 )
T
A
=-40
℃
to
+ 85℃
T
A
=-40
℃
to
+ 105℃
T
A
=-40
℃
to
+ 85℃
T
A
=-40
℃
to
+ 105℃
UM8_L
V
CC
<5.5V, UM8_L/M/J
V
CC
<3.6V, UM8_R/S/T/Z
V
CC
<5.5V, UM8_L/M/J
V
CC
<3.6V, UM8_R/S/T/Z
V
CC
<5.5V, UM8_L/M/J
V
CC
<3.6V,UM 8_R/S/T/Z
V
CC
<5.5V, UM8_L/M/J
V
CC
<3.6V, UM8_R/S/T/Z
T
A
=+25℃
T
A
=-40℃ to + 85℃
T
A
=-40℃ to + 105℃
T
A
=+25℃
T
A
=-40℃ to + 85℃
T
A
=-40℃ to + 105℃
T
A
=+25℃
T
A
=-40℃ to + 85℃
T
A
=-40℃ to + 105℃
T
A
=+25℃
T
A
=-40℃ to + 85℃
T
A
=-40℃ to + 105℃
T
A
=+25℃
T
A
=-40℃ to + 85℃
T
A
=-40℃ to + 105℃
T
A
=+25℃
T
A
=-40℃ to + 85℃
T
A
=-40℃ to + 105℃
TA=+25℃
TA=-40℃ to + 85℃
TA=-40℃ to + 105℃
4.56
4.50
4.40
4.31
4.25
4.16
3.93
3.89
3.80
3.04
3.00
2.92
2.89
2.85
2.78
2.59
2.55
2.50
2.28
2.25
2.20
Min.
1.0
1.2
1.2
Typ.
Max.
10
10
10
Unit
V
3
3
3
3
3
3
3
3
4.63
5
5
6
6
5
5
6
6
4.70
4.75
4.86
4.45
4.50
4.56
4.06
4.10
4.20
3.11
3.15
3.23
2.96
3.00
3.08
2.66
2.70
2.76
2.35
2.38
2.44
uA
I
CC
Supply Current
(SOT23)
I
CC
Supply Current
(SC70)
4.38
UM8_M
4.00
UM8_J
Reset Threshold
(SOT23 only)
V
TH
3.08
UM8_T
V
2.93
UM8_S
2.63
UM8_R
2.32
UM8_Z
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UM809/810
Electrical Characteristics (Continued)
V
CC
= full range, T
A
= -40°C to +105°C (SOT23) or T
A
= -40°C to +125°C (SC70), unless
otherwise noted. Typical values are at T
A
=+25°C, V
CC
= 5V for L/M/J versions, V
CC
= 3.3V for
T/S versions, V
CC
= 3V for R version, and V
CC
= 2.5V for Z version. (Note 1)
Symbol
Parameter
Conditions
TA=+25℃
TA=-40℃ to + 85℃
TA=-40℃ to + 125℃
TA=+25℃
TA=-40℃ to + 85℃
TA=-40℃ to + 125℃
TA=+25℃
TA=-40℃ to + 85℃
TA=-40℃ to + 125℃
TA=+25℃
TA=-40℃ to + 85℃
TA=-40℃ to + 125℃
TA=+25℃
TA=-40℃ to + 85℃
TA=-40℃ to + 125℃
TA=+25℃
TA=-40℃ to + 85℃
TA=-40℃ to + 125℃
TA=+25℃
TA=-40℃ to + 85℃
TA=-40℃ to + 125℃
Min.
4.56
4.50
4.44
4.31
4.25
4.20
3.93
3.89
3.84
3.04
3.00
2.92
2.89
2.85
2.81
2.59
2.55
2.52
2.28
2.25
2.22
Typ.
4.63
Max.
4.70
4.75
4.82
4.45
4.50
4.56
4.06
4.10
4.16
3.11
3.15
3.23
2.96
3.00
3.05
2.66
2.70
2.74
2.35
2.38
2.42
Un
it
UM8_L
4.38
UM8_M
4.00
UM8_J
Reset Threshold
（SC70
only）
V
TH
3.08
UM8_T
V
2.93
UM8_S
2.63
UM8_R
2.32
UM8_Z
Reset Threshold Tempco
V
CC
to Reset Delay（Note 2）
Reset Active Timeout Period
（SOT23
Version）
Reset Active Timeout Period
（SC70
Version）
30
V
CC
=V
TH
to
( V
TH
– 100mV )
140
140
140
140
240
10
240
560
840
460
840
0.3
0.4
0.3
0.8V
CC
V
CC
–
1.5
0.3
0.4
ppm
/℃
us
ms
T
A
=-40
℃
to + 85
℃
T
A
=+85
℃
to + 105
℃
T
A
=-40
℃
to + 85
℃
T
A
=+85
℃
to + 125℃
V
CC
=V
TH
min, I
SINK
=1.2mA,
UM809R/S/T/Z
V
CC
=V
TH
min, I
SINK
=3.2mA,
UM809J/L/M
V
CC
≤1.0V,
I
SINK
=50μA
V
CC
>V
TH
max, I
SOURCE
=500μA,
UM809R/S/T/Z
V
CC
>V
TH
max, I
SOURCE
=800μA,
UM809J/L/M
V
CC
=V
TH
max, I
SINK
=1.2mA,
UM810R/S/T/Z
V
CC
=V
TH
max, I
SINK
=3.2mA,
UM810J/L/M
ms
V
OL
Output Voltage Low
(push-pull active low UM809)
V
V
OH
Output Voltage High
(push-pull active low UM809)
RESET Output Voltage Low
(push-pull active high,
UM810)
V
V
OL
V
RESET Output Voltage High
1.8V < V
CC
< V
TH
min,
0.8V
CC
V
OH
(push-pull active high,
I
SOURCE
= 150µA
UM810)
Note 1:
Production testing done at T
A
= +25°C; limits over temperature guaranteed by design only.
_____________
Note 2:
RESET output for UM809; RESET output for UM810.
V
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UM809/810
Block Diagram
Typical Operating Circuit
Typical Characteristics
The following data is given for UM809 threshold levels: 2.63V, 3.08V, 4.00V and 4.38V.
UM810 threshold levels: 2.63V, 2.93V, 3.08V, 4.38V and 4.63V.
6
6
SUPPLY CURRENT(µA)
SUPPLY CURRENT(µA)
5
4
5
4
V
CC
=5V
3
2
1
0
-40
V
CC
=3V
V
CC
=5V
3
2
1
0
-40
V
CC
=3V
-20
0
20
40
60
85
-20
0
20
40
o
60
85
TEMPERATURE(
o
C)
TEMPERATURE( C)
Figure 1. Supply Current vs Temperature
(No Load,SC70)
Figure 2. Supply Current vs Temperature
(No Load,SOT23-3)
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