MCP120/130
Microcontroller Supervisory Circuit with Open Drain Output
FEATURES
• Holds microcontroller in reset until supply voltage
reaches stable operating level
• Resets microcontroller during power loss
• Precision monitoring of 3V, 3.3V and 5V systems
• 7 voltage trip points available
• Active low RESET pin
• Open drain output
• Internal pull-up resistor (5 kΩ) for MCP130
• Holds RESET for 350 ms (typical)
• RESET to V
CC
= 1.0V
• Accuracy of ±125 mV for 5V systems and ±75 mV
for 3V systems over temperature
• 45
µA
typical operating current
• Temperature range:
- Industrial (I): -40°C to +85°C
PACKAGES
TO-92 with
‘D’ Bondout
TO-92 WITH
‘F’ BONDOUT
RST
V
SS
V
DD
V
SS
V
DD
RST
MCP120
MCP130
MCP130
TO-92 with
‘G’ Bondout
TO-92 with
‘H’ Bondout
DESCRIPTION
The Microchip Technology Inc. MCP120/130 is a volt-
age supervisory device designed to keep a microcon-
troller in reset until the system voltage has reached the
proper level and stabilized. It also operates as protec-
tion from brown-out conditions when the supply voltage
drops below a safe operating level. Both devices are
available with a choice of seven different trip voltages
and both have open drain outputs. The MCP130 has an
internal 5 kΩ pullup resistor. Both devices have active
low RESET pins. The MCP120/130 will assert the
RESET signal whenever the voltage on the V
DD
pin is
below the trip-point voltage.
V
DD
V
SS
RST
V
DD
V
SS
MCP120
RST
MCP120
MCP130
150mil SOIC
RST
V
DD
NC
V
SS
1
2
3
4
8
7
6
5
NC
NC
NC
NC
SOT-23-3
RST
V
DD
V
SS
MCP120
MCP130
MCP120
MCP130
BLOCK DIAGRAM
V
DD
5k
Ω
internal
pull-up on
MCP130
only
RESET
Comparator
+
-
Delay
Circuit
Output
Driver
Bandgap
Reference
2001 Microchip Technology Inc.
DS11184D-page 1
MCP120/130
1.0
1.1
ELECTRICAL CHARACTERISTICS
Maximum Ratings*
*Notice:
Stresses above those listed under “Maximum
Ratings” may cause permanent damage to the device.
This is a stress rating only and functional operation of
the device at those or any other conditions above those
indicated in the operational listings of this specification
is not implied. Exposure to maximum rating conditions
for extended periods may affect device reliability.
V
DD
........................................................................ 7.0V
All inputs and outputs w.r.t. V
SS
.....-0.6V to V
DD
+1.0V
Storage temperature .......................... -65°C to +150°C
Ambient temp. with power applied ..... -65°C to +125°C
ESD protection on all pins
..................................... ≥
2 kV
DC AND AC CHARACTERISTICS
All parameters apply at the
specified temp and voltage
ranges unless otherwise noted.
Parameter
Operating Voltage Range
V
DD
Value to RESET
Operating Current
V
DD
Trip Point
MCP1X0-270
MCP1X0-300
MCP1X0-315
MCP1X0-450
MCP1X0-460
MCP1X0-475
MCP1X0-485
MCP1X0-270
MCP1X0-300
MCP1X0-315
MCP1X0-450
MCP1X0-460
MCP1X0-475
MCP1X0-485
RESET High
MCP130-xxx
Level Output
(All V
TRIP
Points)
Voltage
(MCP130 Only)
Pull-up Resistor (MCP130 Only)
Output Leakage (MCP120 Only)
Threshold Hysteresis
V
DD
Detect to RESET Inactive
V
DD
Detect to RESET
V
HYS
t
RPU
t
RPD
V
OH
V
DD
= 1.0 - 5.5V
Industrial (I): -40°C to +85°C
Symbol
V
DD
V
DD
MIN
I
DD
V
TRIP
Min.
1.0
1.0
—
2.55
2.85
3.0
4.25
4.35
4.50
4.60
—
Typ.
—
—
45
2.625
2.925
3.075
4.375
4.475
4.625
4.725
—
Max.
5.5
—
60
2.7
3.0
3.15
4.50
4.60
4.75
4.85
0.4
Units
V
V
µA
V
V
DD
= 5.5V (no load)
Test Conditions
RESET Low
Level Output
Voltage
V
OL
V
I
OL
= 3.2 mA,
V
DD
= V
TRIP
MIN
I
OL
= 8.5 mA,
V
DD
= V
TRIP
MIN
—
—
0.6
V
DD
-0.7
—
—
V
I
OH
= 50
µA,V
DD
> V
TRIP
MAX
—
—
—
150
—
5
1
50
350
10
—
—
—
700
—
kΩ
µA
mV
ms
µs
V
DD
ramped from V
TRIP
MAX
+
250 mV down to V
TRIP
MIN
-
250 mV
Note:
Typical values are for 25°C and V
DD
= 5.0V
2001 Microchip Technology Inc.
DS11184D-page 2
MCP120/130
V
TRIP
V
DD
t
RPU
t
RPD
RESET
V
OH
V
OH
Figure 1-1:
MCP120/130 Timing Diagram
2001 Microchip Technology Inc.
DS11184D-page 3
MCP120/130
2.0
2.1
APPLICATIONS INFORMATION
The Need for Supervisory Circuits
5V
SUPPLY VOLTAGE
V
TRIP
MAX
V
TRIP
MIN
(V
TRIP
MIN
-
V
DD
)
Transient
Duration
For many of today’s microcontroller applications, care
must be taken to prevent low power conditions that can
cause many different system problems. The most com-
mon causes are brown-out conditions where the sys-
tem supply drops below the operating level momentar-
ily, and the second, is when a slowly decaying power
supply causes the microcontroller to begin executing
instructions without enough voltage to sustain SRAM
and producing indeterminate results.
V
DD
V
DD
Microcontroller
MCP120
V
SS
RST
Bypass
Capacitor
V
DD
0
0
TIME
10
T
A
= +25°C
TRANSIENT DURATION (
µ
S
)
MCLR
or
RESET
8
6
Transients above the
curve will cause a reset
4
V
SS
2
Figure 2-1:
Typical Application
0
Transients below
the curve will NOT
cause a reset
0
1
2
3
V
TRIP
- V
DD
(V)
4
5
2.2
Negative Going V
DD
Transients
Figure 2-2:
Typical Transient Response
Many system designers implementing POR circuits are
concerned about the minimum pulse width required to
cause a reset. Figure 2-2 shows typical transient
voltage below the trip point (V
TRIP
- V
DD
) vs. transient
duration. It shows that the farther below the trip point
the transient pulse goes, the duration of the pulse
required to cause a reset gets shorter. A 0.1
µF
bypass
cap mounted as close as possible to the V
DD
pin pro-
vides additional transient immunity.
DS11184D-page 4
2001 Microchip Technology Inc.
MCP120/130
2.3
Effect of Temperature on Timeout
Period (t
RPU
)
NORMALIZED THRESHOLD* (V
TRIP
)
1.002
1.000
0.998
0.996
0.994
0.992
0.997
-40
The timeout period (t
RPU
) determines how long the
device remains in the reset condition. This is controlled
by an internal RC timer and is effected by both V
DD
and temperature. The graph shown in Figure 2-3
shows typical response for different V
DD
values and
temperatures.
700
TIMEOUT PERIOD (t
RPU
) (ms)
600
V
DD
= 6V
500
V
DD
= 5V
400
300
V
DD
= 4V
200
100
-40
V
DD
= 3V
-20
0
20
40
60
80
100
TEMPERATURE (°C)
* Multiply value at 25°C by this
factor to determine the value at
temperature
Figure 2-5:
Normalized V
TRIP
vs. Temperature
800
-20
0
20
40
60
80
100
700
V
DD
= 1.5V
600
V
OL
(mV)
V
DD
= 3.5V
V
DD
= 2.5V
TEMPERATURE (°C)
Figure 2-3:
t
RPU
vs. Temperature
500
400
300
200
100
V
DD
= 4.5V
60
OPERATING CURRENT (
µ
A)
50
40
30
V
DD
= 4V
20
10
0
-40
V
DD
= 5V
V
DD
= 5.5V
T
A
= +25°C
0
0
V
DD
= 3V
2
4
6
8 10 12 14 16 18 20
I
OL
(mA)
Figure 2-6:
V
OL
vs. I
OL
1.3
-20
0
20
40
60
80
100
1.2
NORMALIZED I
OL
*
1.1
1.00
0.9
0.8
0.7
-40
TEMPERATURE (°C)
Figure 2-4:
I
DD
vs. Temperature
-20
0
20
40
60
TEMPERATURE (°C)
80
100
* Multiply value at 25°C by this
factor to determine the value at
temperature
Figure 2-7:
Normalized I
OL
vs. Temperature
2001 Microchip Technology Inc.
DS11184D-page 5
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