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FM803 3-Pin µC Supervisor Device
FM803 Rev. B.2
FM803
3-Pin µC Supervisor Device
Typical Operating Circuit
November 2001
© 2001 Fairchild Semiconductor Corporation
General Description
The FM803 is a supervisory device designed to monitor power
supply or other system voltage. FM803 generates a reset pulse
whenever the voltage being monitored is out of tolerance. Once
asserted, the reset pulse is guaranteed to be valid for a minimum
of 140ms (256ms typical ). The reset output of FM803 is of active
low Open-Drain type and has an internal pull-up resistor.
Several threshold voltages are offered to accommodate 5.0V,
3.3V, 3.0V and 2.7V system voltages.
These devices are offered in space saving 3-pin SOT23 and SC70
packages.
Features
■Automatic reset generation on power-up
■Minimum 140 ms reset pulse
■Internal 5kΩ pull-up resistor
■Other reset pulse choices available: 32 - 256 ms
■Operating temperature
-40°C to + 105°C (SOT-23)
-40°C to +85°C (SC70)
■Choice of Reset Thresholds: 4.63V, 4.38V, 4.00V, 3.08V,
2.93V, 2.63V
■SOT23-3 and SC70-3 Packages
Connection Diagram
GND
VCC
/RESET
1
FM803
2
3
1
FM803 Controller
2
3
VCC
GND
/RESET
SC70-3 & SOT23-3 Packages
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FM803 3-Pin µC Supervisor Device
FM803 Rev. B.2
Absolute Maximum Ratings
Voltage on any terminal relative to GND
VCC -0.3V to +6.0V
/RESET -0.3V to +6.0V
Input Current 20mA
Output Current: /RESET 20mA
Rate of Rise of VCC 100V/µs
Continuous Power Dissipation (TA = +70°C)
SOT23-3 (derate 4mW/°C above +70°C) 320mW
Operating Temperature Range -40°C to +105°C
Storage Temperature Range -65°C to +150°C
Lead Temperature (soldering, 10s) +300°C
These are stress ratings only, and functional operation is not implied for these levels or beyond. Exposure to Absolute
Maximum Rating conditions for extended periods may affect device reliability.
Electrical Characteristics SOT-23 Package (TA = 25°C unless otherwise noted)
VCC = full range, as noted under conditions. See Note 1.
Parameter Symbol Conditions Min Typ Max Units
(Note 2)
Operating Voltage VCC TA = -40°C to +105°C 1.1 5.5 V
Supply Current ICC TA = -40°C to +105°C, VCC < 5.5V 5 10 µA
FM803J/L/M
TA = -40°C to +105°C, VCC < 3.6V 3 6
FM803R/S/T
Reset Threshold VTH FM803L TA = -40°C to +105°C 4.40 4.63 4.86 V
FM803M TA = -40°C to +105°C 4.18 4.38 4.52
FM803J TA = -40°C to +105°C 3.90 4.00 4.18
FM803T TA = -40°C to +105°C 2.97 3.08 3.19
FM803S TA = -40°C to +105°C 2.79 2.93 3.00
FM803R TA = -40°C to +105°C 2.49 2.63 2.70
Reset Threshold Tempco 30 ppm/°C
VCC to Reset Delay VCC = VTH to (VTH - 100mV) 10 µs
Reset Active Timout Period TA = -40°C to +105°C 140 256 560 ms
FM803 Output Low VOL VCC = VTH(min), ISINK = 1.2mA, 0.3 V
FM803R/S/T
VCC = VTH(min), ISINK = 3.2mA, 0.4
FM803J/L/M
VCC = < 1.0V, ISINK = 50µA 0.3
Open-Drain Output Leakage VCC > VTH(max), IRESET = 1 0.8VCC 1µA
Current
Note 1: Testing in production is 25°C only. Limits over temperature are guaranteed by design.
Note 2: Typical values are at 25°C.
Note 3: If a filter capacitor is used between the Reset pin and Ground pin to suppress noise, do not exceed 100pF.
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FM803 3-Pin µC Supervisor Device
FM803 Rev. B.2
Absolute Maximum Ratings
Voltage on any terminal relative to GND
VCC -0.3V to +6.0V
/RESET -0.3V to (VCC + 0.3V)
Input Current 20mA
Output Current: /RESET 20mA
Rate of Rise of VCC 100V/µs
Continuous Power Dissipation (TA = +70°C)
SC70-3 174mW
Operating Temperature Range -40°C to +85°C
Storage Temperature Range -65°C to +150°C
Lead Temperature (soldering, 10s) +300°C
These are stress ratings only, and functional operation is not implied for these levels or beyond. Exposure to Absolute
Maximum Rating conditions for extended periods may affect device reliability.
Electrical Characteristics SC70 Package (TA = 25°C unless otherwise noted)
VCC = full range, as noted under conditions. See Note 1.
Parameter Symbol Conditions Min Typ Max Units
(Note 3)
Operating Voltage VCC TA = 0°C to +70°C 1.4 5.5 V
TA = -40°C to 85°C 1.6 5.5
Supply Current ICC TA = -40°C to 85°C, VCC < 5.5V 9 15 µA
FM803J/L/M
TA = -40°C to 85°C, VCC < 3.6V 6 10
FM803R/S/T
Reset Threshold VTH FM803L TA = -40°C to +85°C 4.50 4.63 4.75 V
FM803M TA = -40°C to +85°C 4.25 4.38 4.50
FM803J TA = -40°C to +85°C 3.89 4.00 4.10
FM803T TA = -40°C to +85°C 3.00 3.08 3.15
FM803S TA = -40°C to +85°C 2.85 2.93 3.00
FM803R TA = -40°C to +85°C 2.55 2.63 2.70
Reset Threshold Tempco 30 ppm/°C
VCC to Reset Delay (Note 2) VCC = VTH to (VTH - 100mV) 10 µs
Reset Active Timout Period TA = -40°C to +85°C 140 256 560 ms
FM803 Output Low VOL VCC = VTH(min), ISINK = 1.2mA, 0.3 V
FM803R/S/T
VCC = VTH(min), ISINK = 3.2mA, 0.4
FM803J/L/M
VCC = < 1.0V, ISINK = 50µA 0.3
Open-Drain Output Leakage VCC > VTH(max), /RESET = 1 7 µA
Current
Note 1: Testing in production is 25°C only. VCC = 5V for FM803L/M/J, VCC = 3.3V for FM803T/S and VCC = 3V for FM803R. Limits over temperature are guaranteed by design.
Note 2: /RESET output is for FM803.
Note 3: Typical values are at 25°C.
Note 4: If a filter capacitor is used between the Reset pin and Ground pin to suppress noise, do not exceed 100pF.
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FM803 3-Pin µC Supervisor Device
FM803 Rev. B.2
Pin Descriptions
Pin Number Name Function
1 GND GROUND
2 /RESET /RESET remains LOW while VCC is below
VTH, and for at least 140ms after VCC rises
above VTH.
3V
CC
Circuit Timing (Ex: FM803)
When operating properly with 5V VCC (for example), /RESET will
also be about 5V. When VCC starts to fall, /RESET will follow it
down as shown. When VCC drops below VTH, /RESET drops to
ground ("issues a RESET") and stays there unless VCC also falls
below its minimum operating voltage, approx. 1V. At this point, the
supervisor loses control, and its output may rise, only to again
follow VCC down to the ground.
When VCC begins to rise, /RESET follows it until 1.0V or so is
reached, whereupon the device regains control, /RESET is pulled
to ground, etc. When VCC rises above VTH, /RESET comes out of
RESET 140 ms later.
If it is required that a lower value than GND + 1.0V is needed on
RESET signal during VCC ≤ 1V, a 100K resistor may be used on
the device output to GND.
3.3V
V
TH
1V
GND
3.3V
V
TH
1V
GND
V
CC
RESET
140ms
(min)
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FM803 3-Pin µC Supervisor Device
FM803 Rev. B.2
Ordering Information
Part Top RESET Output Package Packing
Number Marking Threshold (V) Type Type Method
FM803LS3X 03L 4.63 Open-Drain, active LOW 3-Pin, SOT23 3000 units in T&R
FM803MS3X 03M 4.38 Open-Drain, active LOW 3-Pin, SOT23 3000 units in T&R
FM803JS3X 03J 4.00 Open-Drain, active LOW 3-Pin, SOT23 3000 units in T&R
FM803TS3X 03T 3.08 Open-Drain, active LOW 3-Pin, SOT23 3000 units in T&R
FM803SS3X 03S 2.93 Open-Drain, active LOW 3-Pin, SOT23 3000 units in T&R
FM803RS3X 03R 2.63 Open-Drain, active LOW 3-Pin, SOT23 3000 units in T&R
FM803LP3X QLY 4.63 Open-Drain, active LOW 3-Pin, SC70 3000 units in T&R
FM803MP3X QMY 4.38 Open-Drain, active LOW 3-Pin, SC70 3000 units in T&R
FM803JP3X QJY 4.00 Open-Drain, active LOW 3-Pin, SC70 3000 units in T&R
FM803TP3X QTY 3.08 Open-Drain, active LOW 3-Pin, SC70 3000 units in T&R
FM803SP3X QSY 2.93 Open-Drain, active LOW 3-Pin, SC70 3000 units in T&R
FM803RP3X QRY 2.63 Open-Drain, active LOW 3-Pin, SC70 3000 units in T&R
Note 4: Devices listed above feature 250ms typical Reset Pulse width. Consult Fairchild sales for other reset pulse width options.
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FM803 3-Pin µC Supervisor Device
FM803 Rev. B.2
0.96~1.14
0.12
0.03~0.10
0.38 REF
0.40
±0.03
2.90
±0.10
0.95
±0.03
0.95
±0.03
1.90
±0.03
0.508REF
0.97REF 1.30
±0.10
0.45~0.60
2.40
±0.10
+0.05
–0.023
0.20 MIN
0.40
±0.03
Physical Dimensions inches (millimeters) unless otherwise noted
Dimensions in millimeters
SOT-23 Package Dimensions
FS Pkg Code AU
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FM803 3-Pin µC Supervisor Device
FM803 Rev. B.2
Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and Fairchild reserves the right at any time without notice to change said circuitry and specifications.
Life Support Policy
Fairchild's products are not authorized for use as critical components in life support devices or systems without the express written
approval of the President of Fairchild Semiconductor Corporation. As used herein:
1. Life support devices or systems are devices or systems which,
(a) are intended for surgical implant into the body, or (b) support
or sustain life, and whose failure to perform, when properly
used in accordance with instructions for use provided in the
labeling, can be reasonably expected to result in a significant
injury to the user.
2. A critical component is any component of a life support device
or system whose failure to perform can be reasonably ex-
pected to cause the failure of the life support device or system,
or to affect its safety or effectiveness.
Fairchild Semiconductor Fairchild Semiconductor Fairchild Semiconductor Fairchild Semiconductor
Americas Europe Hong Kong Japan Ltd.
Customer Response Center Fax: +44 (0) 1793-856858 8/F, Room 808, Empire Centre 4F, Natsume Bldg.
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Physical Dimensions inches (millimeters) unless otherwise noted
SC70 Package Dimensions
.004 (.10)
.026
(.65)
.052
(1.3)
.087 (2.2)
.071 (1.8)
.016 (.40)
.012 (.30)
.043 (1.1)
.032 (.80)
.018 (.45)
.006 (.15)
.010 (.25)
.004 (.10)
.009 (.23)
.005 (.13)
.087 (2.2)
.079 (2.0)
.053 (1.35)
.045 (1.15)
