19-2637; Rev 2; 12/05
µP Supervisors with Separate V
CC
Reset and
Manual Reset Outputs
General Description
The MAX6453–MAX6456 are low-power, dual-voltage
µP supervisors featuring separate V
CC
reset and manu-
al reset outputs. The dual outputs support both soft-
system reset (interrupt) and hard-system reset (reboot)
functions. The reset output asserts when any of the
monitored voltages falls below its specified threshold
and remains asserted for the reset timeout (140ms min)
after all voltages exceed their respective reset thresh-
olds. All devices are offered with nine factory-fixed
reset thresholds for monitoring primary system voltages
(V
CC
) from 1.8V to 5V and an adjustable reset input for
monitoring a secondary system voltage down to 0.63V.
Each device has a manual reset input, a V
CC
reset out-
put, and a manual reset output. The MAX6453/
MAX6454 manual reset output asserts when the manual
reset input is low. It remains asserted for the manual
reset timeout period (140ms min) after the manual reset
input transitions high. The MAX6453/MAX6354 manual
reset input controls only the manual reset output and
does not affect the V
CC
reset output.
The manual reset input of the MAX6455/MAX6456 con-
trols both the manual reset and V
CC
reset outputs. When
the manual reset input is low for less than 3.3s (typ), only
the manual reset output asserts and remains asserted for
the manual reset timeout period (140ms min) after the
manual reset input transitions high. If the manual reset
input is low for at least 3.3s (typ), the reset output also
asserts and remains asserted for the reset timeout peri-
od (140ms min) after the manual reset input transitions
high. This enhanced feature allows the implementation of
a soft/hard-system reset combination.
The MAX6453/MAX6455 have active-low push-pull
reset and manual reset outputs, and the MAX6454/
MAX6456 have active-low open-drain reset and manual
reset outputs. All devices are available in small SOT23-
6 packages and are fully specified over the extended
temperature range (-40°C to +85°C).
Features
♦
Precision Factory-Set Reset Thresholds From
1.6V to 4.6V
♦
Adjustable Threshold to Monitor Voltages Down
to 0.63V
♦
Manual Reset Input with Extended 3.36s Setup
Period
♦
Immune to Short Voltage Transients
♦
Low 6µA Supply Current
♦
Guaranteed Valid Reset Down to V
CC
= 1.0V
♦
Active-Low
RESET
(Push-Pull or Open-Drain)
Outputs
♦
140ms (min) Reset Timeout Period
♦
Small SOT Package
MAX6453–MAX6456
Ordering Information
PART
MAX6453UT_
_S-T
MAX6454UT_
_S-T
MAX6455UT_
_S-T
MAX6456UT_
_S-T
TEMP RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
PIN-PACKAGE
6 SOT23-6
6 SOT23-6
6 SOT23-6
6 SOT23-6
Note:
The “_” is a placeholder for the threshold voltage level of
the devices. A desired threshold level is set by the part num-
ber suffix found in Table 1. All devices are available in tape-
and-reel only. There is a 2500-piece minimum order increment
for standard versions (Table 2). Sample stock is typically held
on standard versions only. Nonstandard versions require a
minimum order increment of 10,000 pieces. Contact factory for
availability.
Devices are available in both leaded and lead-free packaging.
Specify lead-free by replacing “-T” with “+T” when ordering.
Selector Guide appears at end of data sheet.
Applications
Set-Top Boxes
Consumer Electronics
DVD Players
Modems
MP3 Players
Industrial Equipment
Automotive
Medical Devices
MROUT 3
4
GND 2
RESET 1
6
Pin Configurations
TOP VIEW
MR
RESET 1
6
MR
MAX6453
MAX6454
5
RSTIN
GND 2
MAX6455
MAX6456
5
RSTIN
V
CC
MROUT 3
4
V
CC
SOT23-6
SOT23-6
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
µP Supervisors with Separate V
CC
Reset and
Manual Reset Outputs
MAX6453–MAX6456
ABSOLUTE MAXIMUM RATINGS
(All voltages referenced to GND)
V
CC
..........................................................................-0.3V to +6V
Open-Drain
RESET, MROUT
....................................-0.3V to +6V
Push-Pull
RESET, MROUT..........................-0.3V
to (V
CC
+ 0.3V)
MR,
RSTIN ...............................................................-0.3V to +6V
Input Current, All Pins.......................................................±20mA
Continuous Power Dissipation (T
A
= +70°C)
6-Pin SOT23 (derate 8.7mW/°C above +70°C).............696mW
Operating Temperature Range .......................... -40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond 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 beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
CC
= 1.0V to 5.5V, T
A
= -40°C to +85°C, unless otherwise specified. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Operating Voltage Range
V
CC
Supply Current
SYMBOL
V
CC
I
CC
V
CC
= 5.5V, no load
V
CC
= 3.6V, no load
46
44
31
29
V
CC
Reset Threshold
V
TH
26
23
22
17
16
Reset Threshold Tempco
Reset Threshold Hysteresis
RSTIN Threshold
RSTIN Threshold Hysteresis
RSTIN Input Current
RSTIN to Reset Output Delay
Reset Timeout Period
V
CC
to
RESET
Output Delay
MR
Minimum Setup Period
(Pulse Width)
MR
Minimum Input Pulse
MR
Glitch Rejection
MR
to
MROUT
Delay
Manual Reset Timeout Period
t
MRP
140
t
RP
t
RD
t
MR
V
CC
falling at 1mV/µs
MR
to
MROUT
RESET
asserted, MAX6455/MAX6456
1
2.24
3.36
100
200
210
280
4.48
V
TH-RSTIN
V
HYST
I
RSTIN
V
RSTIN
falling at 1mV/µs
140
-25
15
210
20
280
T
A
= 0°C to +85°C
T
A
= -40°C to +85°C
0.615
0.610
2.5
+25
4.50
4.25
3.00
2.85
2.55
2.25
2.12
1.62
1.52
CONDITIONS
MIN
1.0
7
6
4.63
4.38
3.08
2.93
2.63
2.32
2.19
1.67
1.58
60
2
×
V
TH
0.630
0.645
0.650
TYP
MAX
5.5
20
16
4.75
4.50
3.15
3.00
2.70
2.38
2.25
1.71
1.62
ppm/°C
mV
V
mV
nA
µs
ms
µs
µs
s
ns
ns
ms
V
UNITS
V
µA
2
_______________________________________________________________________________________
µP Supervisors with Separate V
CC
Reset and
Manual Reset Outputs
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
= 1.0V to 5.5V, T
A
= -40°C to +85°C, unless otherwise specified. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
MR
to V
CC
Pullup Impedance
V
CC
≥
1.00V, I
SINK
= 50µA, outputs
asserted
RESET, MROUT
Output Low
(Open Drain or Push-Pull)
V
CC
≥
1.20V, I
SINK
= 100µA, outputs
asserted
V
OL
V
CC
≥
2.55V, I
SINK
= 1.2mA, outputs
asserted
V
CC
≥
4.25V, I
SINK
= 3.2mA, outputs
asserted
V
CC
≥
1.80V, I
SOURCE
= 200µA,
outputs deasserted
RESET, MROUT
Output High
(Push-Pull)
V
OH
V
CC
≥
3.15V, I
SOURCE
= 500µA,
outputs deasserted
V
CC
≥
4.75V, I
SOURCE
= 800µA,
outputs deasserted
RESET, MROUT
Output
Open-Drain Leakage Current
MR
Input Low Voltage
MR
Input High Voltage
I
LKG
V
IL
V
IH
0.7
×
V
CC
Outputs deasserted
0.8
×
V
CC
0.8
×
V
CC
0.8
×
V
CC
1
0.3
×
V
CC
µA
V
V
V
SYMBOL
CONDITIONS
MIN
25
TYP
50
MAX
75
0.3
0.3
V
0.3
0.4
UNITS
kΩ
MAX6453–MAX6456
Note 1:
Devices production tested at 25°C. Overtemperature limits are guaranteed by design.
_______________________________________________________________________________________
3
µP Supervisors with Separate V
CC
Reset and
Manual Reset Outputs
MAX6453–MAX6456
Typical Operating Characteristics
(V
CC
= 3.3V, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX6453 toc01
NORMALIZED RESET TIMEOUT PERIOD
vs. TEMPERATURE
1.04
NORMALIZED TIMEOUT PERIOD
1.03
1.02
1.01
1.00
0.99
0.98
0.97
0.96
0.95
0
-40
-15
10
35
60
85
0
MAX6453 toc02
MAXIMUM TRANSIENT DURATION
vs. RESET THRESHOLD OVERDRIVE
MAX6453 toc03
9
8
SUPPLY CURRENT (µA)
7
6
5
4
3
2
1
0
T
A
= -40°C
T
A
= +25°C
T
A
= +85°C
1.05
250
TRANSIENT DURATION (µs)
200
150
RESET OCCURS
ABOVE THE CURVE
100
50
V
TH
= 4.4V
200
400
600
800
1000
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
RESET THRESHOLD OVERDRIVE (mV)
NORMALIZED V
CC
RESET THRESHOLD
vs. TEMPERATURE
MAX6453 toc04
V
CC
TO RESET DELAY
vs. TEMPERATURE
MAX6453 toc05
RSTIN TO RESET DELAY
vs. TEMPERATURE (RSTIN FALLING)
23.6
RSTIN TO RESET DELAY (µs)
23.2
22.8
22.4
22.0
21.6
21.2
20.8
20.4
20.0
RSTIN FALLING AT 1mV/µs
MAX6453 toc06
1.03
NORMALIZED V
CC
RESET THRESHOLD
1.02
1.01
1.00
0.99
0.98
0.97
-40
-15
10
35
60
24.0
23.6
V
CC
TO RESET DELAY (µs)
23.2
22.8
22.4
22.0
21.6
21.2
20.8
20.4
20.0
V
CC
FALLING AT 1mV/µs
24.0
85
-40
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
MANUAL RESET TO MROUT AND
RESET DELAY (MAX6455/MAX6456)
MAX6453 toc07
V
CC
TO RESET DELAY
MAX6453 toc08
V
CC
= 5V
MR (5V/div)
V
CC
= 4.5V
V
TH
= 4.392V
V
CC
= 4.3V
MROUT (5V/div)
V
CC
(100mV/div)
RESET (5V/div)
RESET (2V/div)
TIME (1s/div)
TIME (100µs/div)
4
_______________________________________________________________________________________
µP Supervisors with Separate V
CC
Reset and
Manual Reset Outputs
Pin Description
PIN
MAX6453
MAX6454
MAX6455
MAX6456
NAME
FUNCTION
Active-Low Push-Pull or Open-Drain Output.
RESET
changes from high to low when
V
CC
or RSTIN drops below its selected reset threshold.
RESET
remains low for the
140ms (min) reset timeout period after all monitored power-supply inputs exceed their
selected reset thresholds.
MR
does not affect
RESET
output. For open-drain outputs,
connect to an external pullup resistor.
RESET
Active-Low Push-Pull or Open-Drain Output.
RESET
changes from high to low when
V
CC
or RSTIN drops below its selected reset threshold.
RESET
remains low for the
140ms (min) reset timeout period after all monitored power-supply inputs exceed their
selected reset thresholds.
RESET
changes from high to low after
MR
input is held low
for the 3.36s (typ) setup period and deasserts 140ms (min) after
MR
deasserts. For
open-drain outputs, connect to an external pullup resistor.
Ground
Manual Reset Push-Pull or Open-Drain Output.
MROUT
asserts immediately after
MR
is
pulled low.
MROUT
remains low for 140ms (min) after
MR
is deasserted. For open-
drain outputs, connect to an external pullup resistor.
V
CC
Voltage Input. Power supply and input for the primary microprocessor voltage
reset monitor.
Reset Input. High-impedance input to the adjustable reset comparator. Connect RSTIN
to the center point of an external resistor divider to set the threshold of the externally
monitored voltage.
Manual Reset Input. Internal 50kΩ pullup to V
CC
. Pull
MR
low to immediately assert
MROUT. MR
does not affect
RESET
output.
MR
—
6
Manual Reset Input. Internal 50kΩ pullup to V
CC
. Pull
MR
low to immediately assert
MROUT. RESET
changes from high to low after
MR
input is held low for the 3.36s (typ)
setup period.
MAX6453–MAX6456
1
—
—
1
2
3
2
3
GND
MROUT
4
4
V
CC
5
5
RSTIN
6
—
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