MCP809/MCP810
3-Pin Microprocessor Reset Circuits
General Description
The MCP809/810 microprocessor supervisory circuits can
be used to monitor the power supplies in microprocessor
and digital systems. They provide a reset to the micropro-
cessor during power-up, power-down and brown-out condi-
tions.
The function of the MCP809/810 is to monitor the V
CC
supply voltage, and assert a reset signal whenever this
voltage declines below the factory-programmed reset
threshold. The reset signal remains asserted for 240ms after
V
CC
rises above the threshold. The MCP809 has an
active-low RESET output, while the MCP810 has an
active-high RESET output.
Seven standard reset voltage options are available, suitable
for monitoring 5V, 3.3V, and 3V supply voltages.
With a low supply current of only 15A, the MCP809/810 are
ideal for use in portable equipment. The MCP809/MCP810
are available in the 3-pin SOT23 package.
Features
n
Precise monitoring of 3V, 3.3V, and 5V supply voltages
n
Fully specified over temperature
n
140ms min. Power-On Reset pulse width, 240ms typical
Active-low RESET Output (MCP809)
Active-high RESET Output (MCP810)
n
Guaranteed RESET Output valid for V
CC
1V
n
Low Supply Current, 15A typ.
n
Power supply transient immunity
Applications
n
Microprocessor Systems
n
Computers
n
Controllers
n
Intelligent Instruments
n
Portable/Battery-Powered Equipment
n
Automotive
Typical Application Circuit
20022301
Connection Diagram
20022302
( ) are for MCP810
June 2001
MCP809/MCP810
3-Pin
Microprocessor
Reset
Circuits
2001 National Semiconductor Corporation
DS200223
www.national.com
Ordering Information
Reset Threshold
(V)
MCP809 Supplied as
1000 units, tape & reel
MCP809 Supplied as
3000 units, tape & reel
Package
Top Mark
Package
Type
NSC Package
4.63
MCP809M3-4.63
MCP809M3X-4.63
SVB
SOT23-3
MF03A
4.38
MCP809M3-4.38
MCP809M3X-4.38
SUB
4.00
MCP809M3-4.00
MCP809M3X-4.00
STB
3.08
MCP809M3-3.08
MCP809M3X-3.08
SSB
2.93
MCP809M3-2.93
MCP809M3X-2.93
SRB
2.63
MCP809M3-2.63
MCP809M3X-2.63
SPB
Reset Threshold
(V)
MCP810 Supplied as
1000 units, tape & reel
MCP810 Supplied as
3000 units, tape & reel
Package
Top Mark
Package
Type
NSC Package
4.63
MCP810M3-4.63
MCP810M3X-4.63
SNB
SOT23-3
MF03A
4.38
MCP810M3-4.38
MCP810M3X-4.38
SLB
4.00
MCP810M3-4.00
MCP810M3X-4.00
SKB
3.08
MCP810M3-3.08
MCP810M3X-3.08
SJB
2.93
MCP810M3-2.93
MCP810M3X-2.93
SHB
2.63
MCP810M3-2.63
MCP810M3X-2.63
SGB
Custom voltages and improved accuracies are available, subject to minimum orders. Contact your local National Semiconductor Sales Office for information.
Pin Description
PIN
NAME
FUNCTION
3
GND
Ground reference
1
RESET (MCP809)
Active-low output. RESET remains low while V
CC
is below the reset threshold, and
for 240ms after V
CC
rises above the reset threshold.
RESET (MCP810)
Active-high output. RESET remains high while V
CC
is below the reset threshold, and
for 240ms after V
CC
rises above the reset threshold.
2
V
CC
Supply Voltage (+5V, +3.3V, or +3.0V)
MCP809/MCP810
www.national.com
2
Absolute Maximum Ratings
(Note 1)
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales Office/
Distributors for availability and specifications.
V
CC
-0.3V to 6.0V
RESET, RESET
-0.3V to (V
CC
+ 0.3V)
Input Current, V
CC
Pin
20mA
Output Current, RESET, RESET
Pin
20mA
Rate of Rise, V
CC
100V/s
ESD Rating (Note 2)
2kV
Continuous Power Dissipation (T
A
= +70C)
SOT-23 (Note 3)
320mW
Ambient Temperature Range
-40C to +105C
Maximum Junction Temperature
125C
Storage Temperature Range
-65C to +160C
Lead Temperature (soldering,
10sec)
+300C
Electrical Characteristics
V
CC
= full range, T
A
= -40C to +105C, unless otherwise noted. Typical values are at T
A
= +25C, V
CC
= 5V for
4.63/4.38/4.00 versions, V
CC
= 3.3V for 3.08/2.93 versions, and V
CC
= 3V for 2.63 version. (Note 4)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
V
CC
Range
T
A
= 0C to +70C
1.0
5.5
V
T
A
= -40C to +105C
1.2
5.5
I
CC
Supply Current
T
A
= -40C to
+85C
V
CC
<
5.5V, MCP8_ _
-4.63/4.38/4.00
18
60
A
V
CC
<
3.6V, MCP8_ _
-3.08/2.93/2.63
15
50
T
A
= +85C to
+105C
V
CC
<
5.5V, MCP8_ _
-4.63/4.38/4.00
100
V
CC
<
3.6V, MCP8_ _
-3.08/2.93/2.63
100
V
TH
Reset Threshold (Note 5)
MCP8_ _ -4.63
T
A
= +25C
4.56
4.63
4.70
V
T
A
= -40C to +85C
4.50
4.75
T
A
= +85C to +105C
4.40
4.86
MCP8_ _ -4.38
T
A
= +25C
4.31
4.38
4.45
T
A
= -40C to +85C
4.25
4.50
T
A
= +85C to +105C
4.16
4.56
MCP8_ _ -4.00
T
A
= +25C
3.93
4.00
4.06
T
A
= -40C to +85C
3.89
4.10
T
A
= +85C to +105C
3.80
4.20
MCP8_ _ -3.08
T
A
= +25C
3.04
3.08
3.11
T
A
= -40C to +85C
3.00
3.15
T
A
= +85C to +105C
2.92
3.23
MCP8_ _ -2.93
T
A
= +25C
2.89
2.93
2.96
T
A
= -40C to +85C
2.85
3.00
T
A
= +85C to +105C
2.78
3.08
MCP8_ _ -2.63
T
A
= +25C
2.59
2.63
2.66
T
A
= -40C to +85C
2.55
2.70
T
A
= +85C to +105C
2.50
2.76
Reset Threshold
Temperature Coefficient
30
ppm/C
V
CC
to Reset Delay (Note 5)
V
CC
= V
TH
to (V
TH
- 100mV)
20
s
Reset Active Timeout Period
T
A
= -40C to +85C
140
240
560
ms
T
A
= +85C to +105C
100
840
MCP809/MCP810
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3
Electrical Characteristics
(Continued)
V
CC
= full range, T
A
= -40C to +105C, unless otherwise noted. Typical values are at T
A
= +25C, V
CC
= 5V for
4.63/4.38/4.00 versions, V
CC
= 3.3V for 3.08/2.93 versions, and V
CC
= 3V for 2.63 version. (Note 4)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
V
OL
RESET Output Voltage Low
(MCP809)
V
CC
= V
TH
min, I
SINK
= 1.2mA,
MCP809-2.63/2.93/3.08
0.3
V
V
CC
= V
TH
min, I
SINK
= 3.2mA,
MCP809-4.63/4.38/4.00
0.4
V
CC
>
1.0V, I
SINK
= 50A
0.3
V
OH
RESET Output Voltage High
(MCP809)
V
CC
>
V
TH
max, I
SOURCE
= 500A,
MCP809-2.63/2.93/3.08
0.8V
CC
V
V
CC
>
V
TH
max, I
SOURCE
= 800A,
MCP809-4.63/4.38/4.00
V
CC
-1.5
V
OL
RESET Output Voltage Low
(MCP810)
V
CC
= V
TH
max, I
SINK
= 1.2mA,
MCP810-2.63/2.93/3.08
0.3
V
V
CC
= V
TH
max, I
SINK
= 3.2mA,
MCP810-4.63/4.38/4.00
0.4
V
OH
RESET Output Voltage High
(MCP810)
1.8V
<
V
CC
<
V
TH
min, I
SOURCE
= 150A
0.8V
CC
V
Note 1: Absolute Maximum Ratings are limits beyond which damage to the device may occur. Operating Ratings are conditions under which the device operates
correctly. Operating ratings do not imply guaranteed performance limits. For guaranteed performance limits and associated test conditions, see the Electrical
Characteristics.
Note 2: The human body model is a 100pF capacitor discharged through a 1.5k
resistor into each pin.
Note 3: Production testing done at T
A
= +25C, over temperature limits guaranteed by design only.
Note 4: At elevated temperatures, devices must be derated based on package thermal resistance. The device in the SOT23-3 package must be derated at 4mW/C
at ambient temperatures above 70C. The device has internal thermal protection.
Note 5: RESET Output for MCP809, RESET output for MCP810.
MCP809/MCP810
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4
Typical Performance Characteristics
Supply Current vs Temperature
(No Load, MCP8_ _-2.63/2.93/3.08)
Supply Current vs Temperature
(No Load, MCP8_ _-4.63/4.38)
Power-Down Reset Delay vs Temp
(MCP8_ _-2.63/2.93/3.08)
20022303
20022304
20022305
Power-Down Reset Delay vs
Temperature (MCP8_ _-4.63/4.38)
Power-Up Reset Timeout vs
Temperature
Normalized Reset Threshold vs
Temperature
20022306
20022307
20022308
MCP809/MCP810
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5
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