CAT853, CAT863
CATCAT859,
CAT869
3-Pin Microprocessor Power Supply Supervisors
FEATURES
Precision monitoring of +3.3 V (-5%, -10%), 5 V
(-10% Power Supplies)
Active low reset output
Reset valid down to V
CC
= 1.0 V
6 µA power supply current
Power supply transient immunity
Industrial temperature range: -40ºC to +85ºC
RoHS-compliant SOT-23 package
DESCRIPTION
The CAT853, CAT863, CAT859, and CAT869 are
supervisory circuits that monitor power supplies in
digital systems.
These devices generate a reset signal, which is
asserted while the power supply voltage is below a
preset threshold level and for at least 140 ms after the
power supply level has risen above that level. Industry
standard threshold levels are offered to support
+3.3 V or 5.0 V systems.
¯¯¯¯¯¯
The CAT859 and CAT869 feature a RESET push-pull
output (active low) for the two pinout options.
The CAT853 and CAT863 feature an open drain
¯¯¯¯¯¯
RESET output (active low). Both require a pull-up
resistor on the RESET output.
Fast transients on the power supply are ignored and
the output is guaranteed to be in the correct state at
V
CC
levels as low as 1.0 V.
APPLICATIONS
Computers
Servers
Laptops
Cable modems
Wireless communications
Embedded control systems
White goods
Power meters
Intelligent instruments
PDAs and handheld equipment
For Ordering Information details, see page 9.
PIN CONFIGURATION
SOT-23 3-Lead
RESET
1
RESET
THRESHOLD SUFFIX SELECTOR
SOT-23 3-Lead
1
Nominal Threshold
Voltage
4.38 V
4.20 V
3.08 V
2.93 V
2.4 V
Threshold Suffix
Designation
M
F
T
S
C
CAT853
CAT859
GND
2
3
V
CC
V
CC
2
CAT863
CAT869
3
GND
PIN DESCRIPTION
Pin Name
¯¯¯¯¯¯
RESET
GND
V
CC
Function
¯¯¯¯¯¯
Active low reset.
RESET
is asserted if V
CC
falls below the reset threshold and remains low for at
least 140 ms after V
CC
rises above the reset threshold
Ground
Power supply voltage that is monitored
© 2009 SCILLC. All rights reserved.
Characteristics subject to change without notice
1
Doc. No. MD-3026, Rev. G
CAT853, CAT863, CAT859, CAT869
BLOCK DIAGRAMS
V
CC
V
CC
V
CC
TOLERANCE
BIAS
+
–
DIGITAL
DELAY
RESET
VOLTAGE
REFERENCE
GND
CAT853
CAT863
V
CC
V
CC
TOLERANCE
BIAS
V
CC
+
–
DIGITAL
DELAY
RESET
VOLTAGE
REFERENCE
GND
CAT859
CAT869
Doc. No. MD-3026, Rev. G
2
© 2009 SCILLC. All rights reserved.
Characteristics subject to change without notice
CAT853, CAT863, CAT859, CAT869
ABSOLUTE MAXIMUM RATINGS
(1)
Parameters
Any pin with respect to ground
Input Current, V
CC
¯¯¯¯¯¯
Output Current, RESET
Rate of Rise, V
CC
Continuous Power Dissipation
Derate 4mW/ºC above 70ºC (SOT23)
Operating Temperature Range
Storage Temperature Range
Lead Soldering Temperature (10 sec)
Ratings
-0.3 to +6.0
20
20
100
320
-40 to +85
-65 to +105
300
Units
V
mA
mA
V/µs
mW
ºC
ºC
ºC
ELECTRICAL CHARACTERISTICS
V
CC
= Full range, T
A
= -40ºC to +85ºC unless otherwise noted. Typical values at T
A
= +25ºC and V
CC
= 3.3 V for
the C, S, T versions, V
CC
= 5 V for the M version.
Symbol Parameter
V
CC
Range
I
CC
Supply Current
Conditions
T
A
= 0ºC to +70ºC
T
A
= -40ºC to +85ºC
T
A
= -40ºC to +85ºC
M Threshold
F Threshold
V
TH
Reset Threshold
Voltage
T Threshold
S Threshold
C Threshold
Reset Threshold
Tempco
V
CC
to Reset
Delay
Reset Active
Timeout Period
V
OL
V
OH
¯¯¯¯¯¯
RESET Output
Voltage Low
¯¯¯¯¯¯
RESET Output
Voltage High
V
CC
= V
TH
to (V
TH
- 100 mV)
T
A
= -40ºC to +85ºC
V
CC
= V
TH
min, I
SINK
= 1.2 mA
V
CC
> 1.0 V, I
SINK
= 50 µA
V
CC
= V
TH
max, I
SOURCE
= -500 µA
(for CAT859/869 only)
0.8 V
CC
140
V
CC
< 3.6 V, C, S, T
T
A
= +25ºC
T
A
= -40ºC to +85ºC
T
A
= +25ºC
T
A
= -40ºC to +85ºC
T
A
= +25ºC
T
A
= -40ºC to +85ºC
T
A
= +25ºC
T
A
= -40ºC to +85ºC
T
A
= +25ºC
T
A
= -40ºC to +85ºC
4.31
4.25
4.14
4.08
3.04
3.00
2.89
2.85
2.35
2.30
30
20
240
460
0.4
0.3
2.40
2.93
3.08
4.20
Min
1.0
1.2
6
4.38
Typ
(2)
Max
5.5
5.5
15
4.45
4.50
4.26
4.31
3.11
3.15
2.96
3.00
2.45
2.50
Units
V
µA
V
ppm/ºC
µs
ms
V
V
Notes:
(1) Stresses above 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 outside of those listed in the operational sections of this
specification is not implied. Exposure to any absolute maximum rating for extended periods may affect device performance and reliability.
(2) Production testing done at T
A
= +25ºC; limits over temperature guaranteed by design only.
© 2009 SCILLC. All rights reserved.
Characteristics subject to change without notice
3
Doc. No. MD-3026, Rev. G
CAT853, CAT863, CAT859, CAT869
TYPICAL ELECTRICAL OPERATING CHARACTERISTICS
V
CC
= Full range, T
A
= -40ºC to +85ºC unless otherwise noted. Typical values at T
A
= +25ºC and V
CC
= 3.3 V for
the C, S, T versions, V
CC
= 5 V for the M version.
POWER-UP RESET TIMEOUT
VS. TEMPERATURE
SUPPLY CURRENT VS. TEMPERATURE
(NO LOAD)
12
POWER-UP RESET TIMEOUT (ms)
260
SUPPLY CURRENT (µA)
240
220
200
V
CC
= 5 V
10
8
6
4
2
0
V
CC
= 5.5 V
V
CC
= 3.6 V
V
CC
= 2.5 V
180
160
-50
0
50
100
150
TEMPERATURE (°C)
-50
0
50
100
150
TEMPERATURE (°C)
POWER-DOWN RESET DELAY
VS. TEMPERATURE
NORMALIZED RESET THRESHOLD
VS. TEMPERATURE
1.0002
POWER-DOWN RESET DELAY (µs)
NORMALIZED THRESHOLD
14
12
10
8
6
4
2
0
-50
0
50
100
150
TEMPERATURE (°C)
1
0.9998
0.9996
0.9994
0.9992
0.999
0.9988
0
20
40
60
80
100 120
TEMPERATURE (°C)
Doc. No. MD-3026 Rev. G
4
© 2009 SCILLC. All rights reserved.
Characteristics subject to change without notice
CAT853, CAT863, CAT859, CAT869
DETAILED DESCRIPTION
RESET TIMING
The reset signal is asserted low for the CAT853,
CAT863, CAT859, and CAT869 when the power
supply voltage falls below the threshold trip voltage
and remains asserted for at least 140 ms after the
power supply voltage has risen above the threshold.
Threshold
Voltage
Reset Timeout Period
140 ms
minimum
Power 5 V
Supply
Voltage 0 V
RESET
5V
0V
Figure 1. Reset Timing Diagram
V
CC
TRANSIENT RESPONSE
The CAT853, CAT863, CAT859, and CAT869 protect
µPs against brownout failure. Short duration
transients of 4 µs or less and 100 mV amplitude
typically do not cause a false RESET.
Figure 2 shows the maximum pulse duration of
negative-going V
CC
transients that do not cause a
reset condition. As the amplitude of the transient goes
further below the threshold (increasing V
TH
- V
CC
), the
maximum pulse duration decreases. In this test, the
V
CC
starts from an initial voltage of 0.5 V above the
threshold and drops below it by the amplitude of the
overdrive voltage (V
TH
- V
CC
).
TRANSIENT DURATION [s]
T
AMB
= 25ºC
“C” THRESHOLD
“M” THRESHOLD
RESET OVERDRIVE V
TH
- V
CC
[mV]
Figure 2. Maximum Transient Duration Without Causing a Reset Pulse vs. Reset Comparator Overdrive
© 2009 SCILLC. All rights reserved.
Characteristics subject to change without notice
5
Doc. No. MD-3026, Rev. G
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