IMP809, IMP81 0
P
OWER
M
ANAGEMENT
3-Pin Microcontroller
Power Supply Supervisor
The IMP809/IMP810 are 3.0V, 3.3V and 5.0V power supply supervisor cir-
cuits optimized for low-power microprocessor (µP), microcontroller (µC)
and digital systems. The IMP809/810 are improved drop-in replacements
for the Maxim MAX809/810 and feature 60% lower supply current.
A reset signal is issued if the power supply voltage drops below a preset
reset threshold and is asserted for at least 140ms after the supply has
risen above the reset threshold. The IMP809 has an active-low RESET
output that is guaranteed to be in the correct state for V
CC
down to 1.1V.
The IMP810 has an active-high RESET output. The reset comparator is
designed to ignore fast transients on V
CC
.
Low supply current makes the IMP809/IMP810 ideal for use in portable
and battery operated equipment. The IMP809/IMP810 are available in a
compact 3-pin SOT23 package.
Six voltage thresholds are available to support 3V to 5V systems:
Key Features
x
Improved Maxim MAX809/MAX810 replacement
— Lower supply current…6µA
— 80% lower maximum supply current
x
Monitor 5V, 3.3V and 3V supplies
x
140ms min. reset pulse width
x
Active-low reset valid with 1.1V supply
(IMP809)
x
Small 3-pin SOT-23 package
x
No external components
x
Specified over full temperature range
— – 40°C to 105°C
Applications
x
x
x
x
x
Embedded controllers
Battery operated systems
Intelligent instruments
Wireless communication systems
PDAs and handheld equipment
Reset Threshold
Suffix
Voltage (V)
L
M
J
T
S
R
4.63
4.38
4.00
3.08
2.93
2.63
Block Diagrams
VCC
VCC
IMP809
(IMP810)
RESET
(RESET)
GND
RESET
Input
VCC
µP
GND
809/10_01.eps
IMP, Inc.
San Jose, CA
408-432-9100/www.impweb.com
IMP809, IMP81 0
Pin Configuration
SOT23
GND 1
IMP809
(IMP810)
3 V
CC
(RESET) RESET 2
809/10_02.eps
Ordering Information
Part Number
1
Reset Threshold (V)
IMP809 Active LOW Reset
IMP809LEUR-T
IMP809MEUR-T
IMP809JEUR-T
IMP809TEUR-T
IMP809SEUR-T
IMP809REUR-T
4.63
4.38
4.00
3.08
2.93
2.63
4.63
4.38
4.00
3.08
2.93
2.63
Temperature Range
– 40°C to +105°C
– 40°C to +105°C
– 40°C to +105°C
– 40°C to +105°C
– 40°C to +105°C
– 40°C to +105°C
– 40°C to +105°C
– 40°C to +105°C
– 40°C to +105°C
– 40°C to +105°C
– 40°C to +105°C
– 40°C to +105°C
Pin-Package
3-SOT23
3-SOT23
3-SOT23
3-SOT23
3-SOT23
3-SOT23
3-SOT23
3-SOT23
3-SOT23
3-SOT23
3-SOT23
3-SOT23
Package Marking
2
(XX Lot Code)
AAXX
ABXX
CWXX
ACXX
ADXX
AFXX
AGXX
AHXX
AIXX
AJXX
AKXX
ALXX
IMP810 Active HIGH Reset
IMP810LEUR-T
IMP810MEUR-T
IMP810JEUR-T
IMP810TEUR-T
IMP810SEUR-T
IMP810REUR-T
Notes:
1. Tape and Reel packaging is indicated by the -T designation.
2. Devices may also be marked with full part number: 809L, 810M etc. XX refers to lot.
Related Products
IMP809
Max. Supply Current
Package Pins
Manual RESET input
Package Type
Active-HIGH RESET output
Active-LOW RESET output
2
IMP810
15µA
3
SOT-23
s
IMP811
15µA
4
s
SOT-143
s
IMP812
15µA
4
s
SOT-143
s
15µA
3
SOT-23
s
IMP809, IMP810
Absolute Maximum Ratings
Pin Terminal Voltage with Respect to Ground
V
CC
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3V to 6.0V
RESET, RESET . . . . . . . . . . . . . . . . . . . . . . . . . –0.3V to (V
CC
+ 0.3V)
Input Current at V
CC
. . . . . . . . . . . . . . . . . . . 20mA
Output Current: RESET, RESET . . . . . . . . . 20mA
Rate of Rise at V
CC
. . . . . . . . . . . . . . . . . . . . 100V/µs
These are stress ratings only and functional operation is not implied.
Exposure to absolute maximum ratings for prolonged time periods may
affect device reliability
Power Dissipation (T
A
= 70
°
C) . . . . . . . . . . 320mW
(Derate 4mW/°C above 70
°
C)
Operating Temperature Range . . . . . . . . . . –40°C to 105°C
Storage Temperature Range . . . . . . . . . . . . . –65°C to 160°C
Lead Temperature (soldering, 10 sec) . . . . . 300°C
Electrical Characteristics
Unless otherwise noted V
CC
is over the full voltage range, T
A
= –40°C to 105°C.
Typical values at T
A
= 25°C, V
CC
= 5V for L/M/J devices, V
CC
= 3.3V for T/S devices and V
CC
= 3V for R devices.
Parameter
Input Voltage (V
CC
) Range
Supply Current
Symbol Conditions
V
CC
I
CC
T
A
= 0°C to 70°C
T
A
= – 40°C to 105°C
T
A
= – 40°C to 85°C
T
A
= – 40°C to 85°C
T
A
= 85°C to 105°C
T
A
= 85°C to 105°C
L devices
V
CC
< 5.5V, L/M/J
V
CC
< 3.6V, R/S/T
V
CC
< 5.5V, L/M/J
V
CC
< 3.6V, R/S/T
T
A
= 25°C
T
A
= – 40°C to 85°C
T
A
= 85°C to 105°C
T
A
= 25°C
T
A
= – 40°C to 85°C
T
A
= 85°C to 105°C
T
A
= 25°C
T
A
= – 40°C to 85°C
T
A
= 85°C to 105°C
T
A
= 25°C
T
A
= – 40°C to 85°C
T
A
= 85°C to 105°C
T
A
= 25°C
T
A
= – 40°C to 85°C
T
A
= 85°C to 105°C
T
A
= 25°C
T
A
= – 40°C to 85°C
T
A
= 85°C to 105°C
Min
1.1
1.2
Typ
9
6
Max
5.5
5.5
15
10
25
20
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
Units
V
µA
Reset Threshold
V
TH
M devices
J devices
T devices
S devices
R devices
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
4.63
V
4.38
4.00
3.08
2.93
2.63
Reset Threshold Stability
V
CC
to Reset Delay
Reset Active Timeout Period
Low RESET Output Voltage
(IMP809)
V
OL
V
OL
High RESET Output Voltage
(IMP809)
Low RESET Output Voltage
(IMP810)
High RESET Output Voltage
(IMP810)
Notes:
V
OH
V
OL
V
OH
V
CC
= V
TH
to V
TH
- 100mV
T
A
= – 40°C to 85°C
140
T
A
= 85°C to 105°C
100
V
CC
= V
TH
min., I
SINK
= 1.2mA, IMP809R/S/T
V
CC
= V
TH
min., I
SINK
= 3.2mA, IMP809L/M/J
V
CC
> 1.1V, I
SINK
= 50µA
V
CC
> V
TH
max., I
SOURCE
= 500µA, IMP809R/S/T 0.8V
CC
V
CC
> V
TH
max., I
SOURCE
= 800µA, IMP809L/M/J V
CC
-1.5
V
CC
= V
TH
max., I
SINK
= 1.2mA, IMP810R/S/T
V
CC
= V
TH
max., I
SINK
= 3.2mA, IMP810L/M/J
1.8V < V
CC
< V
TH
min., I
SOURCE
= 150µA
0.8V
CC
30
20
240
560
840
0.3
0.4
0.3
ppm/°C
µs
ms
V
V
0.3
0.4
V
V
1. Production testing done at T
A
= 25°C. Over-temperature specifications guaranteed by design only.
2.R
SET output is active LOW for the IMP809 and RESET output is active HIGH for the IMP810
E
3
IMP809, IMP81 0
Pin Descriptions
Pin Number
1
2
(IMP809)
2
(IMP810)
3
Name
GND
RESET
RESET
V
CC
Function
Ground
RESET is asserted LOW if V
CC
falls below the reset threshold and remains LOW for the
240ms typical reset timeout period (140ms minimum) after V
CC
exceeds the threshold.
RESET is asserted HIGH if V
CC
falls below the reset threshold and remains HIGH for the
240ms typical reset timeout period (140ms minimum) after V
CC
exceeds the threshold.
Power supply input voltage (3.0V, 3.3V, 5.0V)
Detailed Descriptions
Reset Timing
The reset signal is asserted–LOW for the IMP809 and HIGH for the
IMP810–when the V
CC
signal falls below the threshold trip voltage
and remains asserted for 140ms minimum after the V
CC
has risen
above the threshold.
5V
V
CC
0V
V
TH
Active Reset
Timeout Period
140ms
minimum
IMP809
5V
RESET
0V
5V
RESET
0V
IMP810
809/10_03.eps
Figure 1. Reset Timing Diagram
4
IMP809, IMP810
Application Information
Negative V
CC
Transients
The IMP809/810 protect µPs from brownouts and low V
CC
. Short
duration transients of 100mV amplitude and 20µs or less duration
typically do not cause a false RESET.
Valid Reset with V
CC
under 1.1V
To ensure logic inputs connected to the IMP809 RESET pin are in
a known state when V
CC
is under 1.1V, a 100kΩ pull-down
resistor at RESET is needed. The value is not critical. A pull-up
resistor to V
CC
is needed with the IMP810.
VCC
VCC
100kΩ
Power
Supply
IMP809
RESET
GND
100kΩ
Power
Supply
IMP810
RESET
GND
809/10_04.eps
809/10_05.eps
Figure 2. RESET Valid with V
CC
Under 1.1V
Figure 3. RESET Valid with V
CC
Under 1.1V
Bi-directional Reset Pin Interfacing
The IMP809/810 can interface with µP/µC bi-directional reset
pins by connecting a 4.7kΩ resistor in series with the
IMP809/810 reset output and the µP/µC bi-directional reset pin.
BUF
Buffered
RESET
VCC
Power
Supply
IMP809
4.7kΩ
RESET
GND
Bi-directional I/O Pin
(Example: 68HC11)
µC
or
µP
RESET
Input
GND
809/10_06.eps
Figure 4. Bi-directional Reset Pin Interfacing
5
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