19-1508; Rev 1; 10/99
Dual/Triple-Voltage
µP Supervisory Circuits
General Description
The MAX6351–MAX6360 microprocessor (µP) supervi-
sors with multiple reset voltages significantly improve
system reliability and accuracy compared to separate
ICs or discrete components. If any input supply voltage
drops below its associated preset threshold, all reset
outputs are asserted. In addition, the output(s) is valid
as long as either input supply voltage remains greater
than +1.0V.
All devices in this series have an active-low debounced
manual reset input. In addition, the MAX6358/MAX6359/
MAX6360 offer a watchdog timer input with a 46.4sec
start-up timeout period and a 2.9sec timeout period.
The MAX6355/MAX6356/MAX6357 offer an additional
voltage monitor input to monitor a third voltage.
The MAX6351 features both 3V and 5V active-low push-
pull reset outputs. The MAX6353/MAX6356/MAX6359
offer a 5V active-low push-pull reset. The MAX6354/
MAX6357/MAX6360 offer a 3V active-low push-pull
reset. The MAX6352/MAX6355/MAX6358’s reset is
active-low open-drain.
All of these devices are offered with a wide variety of
voltage threshold levels, as shown in the
Voltage
Threshold Levels
table below. They are available in 5-
and 6-pin SOT23 packages and operate over the
extended (-40°C to +85°C) temperature range.
Features
o
Precision Monitoring of Multiple +2.5V, +3.0V,
+3.3V, and +5V Power-Supply Voltages
o
Precision Factory-Set Power-Supply
Reset Thresholds
o
20µA Supply Current
o
100ms min Power-On Reset Pulse Width
o
Fully Guaranteed Over Temperature
o
Guaranteed
RESET
Valid to V
CC
5 = 1V or
V
CC
3 = 1V
o
Power-Supply Transient Immunity
o
No External Components for Dual-Voltage
Systems
o
Small 5- and 6-Pin SOT23 Packages
o
Debounced TTL/CMOS-Compatible
Manual-Reset Input
o
Watchdog Timer
46.4sec Start-Up Timeout
2.9sec Normal Timeout
o
Low Cost
MAX6351–MAX6360
Applications
Computers
Controllers
Portable/Battery-Powered
Equipment
Intelligent Instruments
Multivoltage Systems
PART*
MAX6351_
_UT-T
MAX6352_
_UK-T
MAX6353_
_UK-T
MAX6354_
_UK-T
MAX6355_
_UT-T
MAX6356_
_UT-T
MAX6357_
_UT-T
MAX6358_
_UT-T
MAX6359_
_UT-T
MAX6360_
_UT-T
Ordering Information
TEMP. RANGE
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-40°C to +85°C
-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
5 SOT23-5
5 SOT23-5
5 SOT23-5
6 SOT23-6
6 SOT23-6
6 SOT23-6
6 SOT23-6
6 SOT23-6
6 SOT23-6
__________Voltage Threshold Levels
PART NO.
SUFFIX
(_ _)
LT
LS
LR
MT
MS
MR
TY
SY
V
CC
5 NOMINAL
VOLTAGE
THRESHOLD (V)
4.63
4.63
4.63
4.38
4.38
4.38
3.08
2.93
V
CC
3 NOMINAL
VOLTAGE
THRESHOLD (V)
3.08
2.93
2.63
3.08
2.93
2.63
2.19
2.19
*The
_ _ are placeholders for the threshold voltage levels of the
devices. Substitute the part number suffix in the Voltage
Threshold Levels table for the desired voltage level. There are
two standard versions for each of the above part numbers. All
devices are available in tape-and-reel only.
Note:
Standard versions are shown in bold and have a required
order increment of 2500 pieces. Sample stock is generally held on
the standard versions only. The required order increment for non-
standard versions is 10,000 pieces. Contact factory for availability.
Pin Configurations appear at end of data sheet.
Selector Guide appears at end of data sheet.
1
________________________________________________________________
Maxim Integrated Products
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
Dual/Triple-Voltage
µP Supervisory Circuits
MAX6351–MAX6360
ABSOLUTE MAXIMUM RATINGS
V
CC
5, V
CC
3 to GND .................................................-0.3V to +6V
RST
(MAX6352/55/58) ............................................. -0.3V to +6V
RST, MR,
WDI,
RST5,
RSTIN
(MAX6351/53/56/59).............................-0.3V to (V
CC
5 + 0.3V)
RST, RST3
(MAX6351/54/57/60) .................-3V to (V
CC
3 + 0.3V)
Input/Output Current, All Pins .............................................20mA
Continuous Power Dissipation (T
A
= +70°C)
5-Pin SOT23-5 (derate 7.1mW/°C above +70°C) ........571mW
6-Pin SOT23-6 (derate 7.1mW/°C above +70°C) ........571mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10sec) .............................+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
3 = V
CC
5 = +1.2V to +5.5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Supply Voltage Range (Note 2)
Supply Current
SYMBOL
V
CC
I
CC
5 +
I
CC
3
CONDITIONS
T
A
= 0°C to +70°C
T
A
= -40°C to +85°C
V
CC
5 = 5.5V, V
CC
3 = 3.6V, all I/O pins open
MAX63_ _L_
MAX63_ _M_
V
CC
5 Threshold (Note 3)
V
TH
5
MAX63_ _T_
MAX63_ _S_
MAX63_ _ _T
MAX63_ _ _S
V
CC
3 Threshold (Note 3)
V
TH
3
MAX63_ _ _R
MAX63_ _ _Y
Reset Threshold Tempco
Reset Threshold Hysteresis
V
CC
to Reset Delay
Reset Timeout Period
t
RP
100mV overdrive
V
CC
5 > V
TH
5
(MAX)
, V
CC
3 > V
TH
3
(MAX)
V
CC
5 or V
CC
3
≥
2.7V, I
SINK
= 1.2mA
V
CC
5 or V
CC
3
≥
4.5V, I
SINK
= 3.2mA
RESET
Output Voltage Low
V
OL
V
CC
5 or V
CC
3 < 1V, I
SINK
= 50µA,
T
A
= 0°C to +70°C
V
CC
5 or V
CC
3 < 1.2V, I
SINK
= 50µA
100
∆V
TH
/°C
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
T
A
= +25°C
T
A
= -40°C to +85°C
4.54
4.5
4.3
4.25
3.03
3.00
2.88
2.85
3.03
3.00
2.88
2.85
2.58
2.55
2.16
2.13
20
V
TH
/500
20
180
280
0.3
0.4
0.3
0.3
V
V
2.19
2.63
2.93
3.08
2.93
3.08
4.38
MIN
1.0
1.2
20
4.63
TYP
MAX
5.5
5.5
50
4.72
4.75
4.46
4.50
3.14
3.15
2.98
3.00
3.14
3.15
2.98
3.00
2.68
2.70
2.22
2.25
ppm/°C
V
µs
ms
V
V
UNITS
V
µA
2
_______________________________________________________________________________________
Dual/Triple-Voltage
µP Supervisory Circuits
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
3 = V
CC
5 = +1.2V to +5.5V, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
SYMBOL
CONDITIONS
MAX6351/MAX6353/
MAX6354/MAX6356/
MAX6357/MAX6359/
MAX6360
(_Y versions only),
V
CC
5 > V
TH
5
(MAX)
,
V
CC
3 > V
TH
3
(MAX)
RESET
Output Voltage High
V
OH
MAX6351/MAX6353/
MAX6354/MAX6356/
MAX6357/MAX6359/
MAX6360
I
SOURCE
= 800µA
(L_, M_ versions only),
V
CC
5 > V
TH
5
(MAX)
,
V
CC
3 > V
TH
3
(MAX)
WATCHDOG INPUT
(MAX6358/MAX6359/MAX6360)
Watchdog Timeout Period
WDI Pulse Width (Note 4)
WDI Input Threshold (Note 5)
WDI Input Current (Note 6)
MANUAL RESET INPUT
V
IL
MR
Input
V
IH
V
IL
V
IH
MR
Pull-Up Resistance
MR
Minimum Pulse Width
MR
Glitch Rejection
MR
to Reset Delay
t
MD
V
CC
5 > V
TH
5
(MAX),
V
CC
3 > V
TH
3
(MAX)
T
A
= +25°C
T
A
= -40°C to +85°C
1.20
1.19
-25
2.5
ADJUSTABLE RESET COMPARATOR INPUT
(MAX6355/MAX6356/MAX6357)
RSTIN Input Threshold
RSTIN Input Current
RSTIN Hysteresis
V
RSTIN
I
RSTIN
1.22
1.24
1.25
25
V
nA
mV
t
RP
MAX63_ _L_, MAX63_ _M_, V
CC
5 > V
TH
5
(MAX)
MAX63_ _L_, MAX63_ _M_, V
CC
5 > V
TH
5
(MAX)
MAX63_ _ _Y, V
CC
5 > V
TH
5
(MAX)
MAX63_ _ _Y, V
CC
5 > V
TH
5
(MAX)
32
10
100
0.1
63.5
0.3V
CC
0.7V
CC
100
kΩ
µs
ns
µs
0.8
2.3
V
t
WD
t
WDI
V
IL
V
IH
First timeout period after reset
After first WDI falling edge
V
IL
= 0.4V, V
IH
= 0.8V
CC
V
CC
3 = 5V
V
WDI
= V
CC
V
WDI
= 0
-20
25.6
1.6
50
0.3V
CC
0.7V
CC
120
-15
160
46.4
2.9
72.0
4.5
sec
ns
V
µA
MIN
TYP
MAX
UNITS
MAX6351–MAX6360
I
SOURCE
= 500µA
0.8V
CC
V
V
CC
- 1.5
0 < V
RISTIN
< V
CC
5 - 0.3V
Note 1:
Overtemperature limits are guaranteed by design and not production tested.
Note 2:
The reset output is guaranteed to be in the correct state if either V
CC
3 or V
CC
5 is within its specified region of operation.
Note 3:
The reset output(s) is asserted if either V
CC
5 or V
CC
3 drops below its associated trip point.
Note 4:
Guaranteed by design. Not production tested.
Note 5:
WDI is internally serviced within the watchdog timeout period if WDI is left unconnected.
Note 6:
The WDI input current is specified as the average input current when the WDI input is driven high or low.
_______________________________________________________________________________________
3
Dual/Triple-Voltage
µP Supervisory Circuits
MAX6351–MAX6360
Typical Operating Characteristics
(V
CC
= +5V, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. TEMPERATURE
MAX6351/60-01
RESET vs. V
CC
5 (V
CC
3 = 3V)
MAX6351/60-02
RESET vs. V
CC
5 (V
CC
3 = GND)
4.5
4.0
3.5
RESET (V)
V
CC
V
CC
5 OR V
CC
3
RST
RST3
RST5
10k
MAX6351/60-03
MAX6351/60-06
20
I
CC
5 (V
CC
5 = 5.0V, V
CC
3 = 3.3V)
SUPPLY CURRENT (µA)
15
I
CC
5 (V
CC
5 = 3.3V, V
CC
3 = 2.5V)
10
5.0
4.5
4.0
3.5
RESET (V)
3.0
2.5
2.0
1.5
1.0
V
TH
5.0
3.0
2.5
2.0
1.5
1.0
0.5
0
MAX6351
MAX6360
5
I
CC
3 (V
CC
5 = 5.0V, V
CC
3 = 3.3V)
I
CC
3 (V
CC
5 = 3.3V, V
CC
3 = 2.5V)
0.5
0
85
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
V
CC
5 (V)
0
-40
-15
10
35
60
TEMPERATURE (°C)
0
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0
V
CC
5 (V)
NORMALIZED RESET/WATCHDOG
PERIOD vs. TEMPERATURE
MAX6351/60-04
MAXIMUM V
CC
TRANSIENT DURATION
vs. RESET THRESHOLD OVERDRIVE
RESET OCCURS ABOVE LINE
250
TRANSIENT DURATION (µs)
200
150
100
50
0
MAX6351/60-05
RESET DELAY vs.
RESET THRESHOLD OVERDRIVE
250
1.20
1.15
NORMALIZED PERIOD
1.10
1.05
1.00
0.95
0.90
0.85
0.80
-60
-40
-20
0
20
40
60
80
300
200
RESET DELAY (µs)
150
100
DELAY FROM FALL OF V
CC
3
50
DELAY FROM FALL OF V
CC
5
0
100
0.01
0.1
1
0
0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
RESET THRESHOLD OVERDRIVE, V
RST
- V
CC
(V)
TEMPERATURE (°C)
RESET THRESHOLD OVERDRIVE, V
RST
- V
CC
(V)
PULL-UP CHARACTERISTICS
MAX6351/60-07
PULL-DOWN CHARACTERISTICS
AND MANUAL RESET DELAY
MAX6351/60-08
5V
0
5V PUSH-PULL
OUTPUT
5V
MR
0
5V
OPEN-DRAIN
OUTPUT
0
3V
0
400ns/div
OPEN-DRAIN
OUTPUT
5V
0
3V PUSH-PULL
OUTPUT
5V PUSH-PULL
OUTPUT
40ns/div
5V
0
5V
0
3V PUSH-PULL
OUTPUT
4
_______________________________________________________________________________________
Dual/Triple-Voltage
µP Supervisory Circuits
Pin Description
PIN
MAX6351
1
MAX6352
MAX6353
MAX6354
—
MAX6355
MAX6356
MAX6357
—
MAX6358
MAX6359
MAX6360
—
NAME
FUNCTION
MAX6351–MAX6360
RST5
Active-Low, 5V CMOS Reset Output
Active-Low Reset Output. Open-drain for the
MAX6352/MAX6355/MAX6358, 5V push-pull for the
MAX6353/MAX6356/MAX6359, and 3V push-pull for
the MAX6354/MAX6357/MAX6360.
Ground
Manual-Reset Input. Pull low to force a reset.
RST,
RST5,
and
RST3
remain active as long as
MR
is low
and for the timeout period after
MR
goes high.
Leave unconnected or connect to V
CC
5 if unused.
V
MR
must be below V
CC
5.
+3.3V/+3.0V Supply Input. Powers the device when
it is above V
CC
5 and monitors its own voltage.
Active-Low, 3V CMOS Reset Output
Undervoltage Reset Comparator Input. Asserts
reset when the monitored voltage falls below 1.23V.
Set the reset threshold with an external resistor-
divider. Connect to V
CC
5 if unused. V
RSTIN
must be
below V
CC
5.
Watchdog Input. If WDI remains either high or low
longer than the timeout period, then reset is trig-
gered. The timer clears when reset is asserted or
whenever WDI sees a rising or falling edge. Leave
floating to disable it if unused.
+5V Supply Input. Powers the device when it is
above V
CC
3 and monitors its own voltage.
—
1
1
1
RST
2
2
2
2
GND
3
3
3
3
MR
4
5
4
—
4
—
4
—
V
CC
3
RST3
—
—
5
—
RSTIN
—
—
—
5
WDI
6
5
6
6
V
CC
5
_______________________________________________________________________________________
5