19-2325; Rev 2; 10/02
Dual/Triple Ultra-Low-Voltage SOT23 µP
Supervisory Circuits
General Description
The MAX6715–MAX6729 are ultra-low-voltage microproces-
sor (µP) supervisory circuits designed to monitor two or three
system power-supply voltages. These devices assert a sys-
tem reset if any monitored supply falls below its factory-
trimmed or adjustable threshold and maintain reset for a
minimum timeout period after all supplies rise above their
thresholds. The integrated dual/triple supervisory circuits sig-
nificantly improve system reliability and reduce size com-
pared to separate ICs or discrete components.
These devices monitor primary supply voltages (V
CC
1) from
1.8V to 5.0V and secondary supply voltages (V
CC
2) from
0.9V to 3.3V with factory-trimmed reset threshold voltage
options (see
Reset Voltage Threshold Suffix Guide).
An
externally adjustable RSTIN input option allows customers to
monitor a third supply voltage down to 0.62V. These devices
are guaranteed to be in the correct reset output logic state
when either V
CC
1 or V
CC
2 remains greater than 0.8V.
A variety of push-pull or open-drain reset outputs along with
watchdog input, manual reset input, and power-fail input/out-
put features are available (see
Selector Guide).
Select reset
timeout periods from 1.1ms to 1120ms (min) (see
Reset
Timeout Period Suffix Guide).
The MAX6715–MAX6729 are
available in small 5, 6, and 8-pin SOT23 packages and oper-
ate over the -40°C to +85°C temperature range.
Features
o
V
CC
1 (primary supply) Reset Threshold Voltages
from 1.58V to 4.63V
o
V
CC
2 (secondary supply) Reset Threshold
Voltages from 0.79V to 3.08V
o
Externally Adjustable RSTIN Threshold for
Auxiliary/Triple-Voltage Monitoring
(0.62V internal reference)
o
Watchdog Timer Option
35s (min) Long Startup Period
1.12s (min) Normal Timeout Period
o
Manual Reset Input Option
o
Power-Fail Input/Power-Fail Output Option
(Push-Pull and Open-Drain Active-Low)
o
Guaranteed Reset Valid Down to V
CC
1 or
V
CC
2 = 0.8V
o
Reset Output Logic Options
o
Immune to Short V
CC
Transients
o
Low Supply Current 14µA (typ) at 3.6V
o
Small 5, 6, and 8-Pin SOT23 Packages
MAX6715–MAX6729
Applications
Multivoltage Systems
Telecom/Networking Equipment
Computers/Servers
Portable/Battery-Operated Equipment
Industrial Equipment
Printer/Fax
Set-Top Boxes
PART
MAX6715UT_
_D_ -T
MAX6716UT_
_D_ -T
MAX6717UK_
_D_ -T
MAX6718UK_
_D_ -T
MAX6719UT_
_D_ -T
MAX6720UT_
_D_ -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
PIN-PACKAGE
6 SOT23-6
6 SOT23-6
5 SOT23-5
5 SOT23-5
6 SOT23-6
6 SOT23-6
Typical Operating Circuit
OUT2
DC/DC
CONVERTER
OUT1
V
CC
1
R1
RST
RSTIN/PFI
MR
R2
PUSHBUTTON
SWITCH
MAX67_ _
WDI
PFO
RESET
I/O
NMI
µP
V
CC
2
UNREGULATED
DC
IN
1.8V
0.9V
I/O
CORE
SUPPLY SUPPLY
Note:
The first “_ _” are placeholders for the threshold voltage
levels of the devices. Desired threshold levels are set by the part
number suffix found in the Reset Voltage Threshold Suffix Guide.
The “_” after the D is a placeholder for the reset timeout delay
time. Desired delay time is set using the timeout period suffix
found in the Reset Timeout Period Suffix Guide. For example the
MAX6716UTLTD3-T is a dual-voltage supervisor V
TH
1 = 4.625V,
V
TH
2 = 3.075V, and 210ms (typ) timeout period.
Ordering Information continued at end of data sheet.
Pin Configurations appear at end of data sheet.
Selector Guide appears at end of data sheet.
________________________________________________________________
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.
Dual/Triple Ultra-Low-Voltage SOT23 µP
Supervisory Circuits
MAX6715–MAX6729
ABSOLUTE MAXIMUM RATINGS
Terminal Voltage (with respect to GND)
V
CC
1, V
CC
2 ..........................................................-0.3V to +6V
Open-Drain
RST, RST1, RST2, PFO,
RST ................-0.3V to +6V
Push-Pull RST,
RST1, PFO, RST...............-0.3V
to (V
CC
1 + 0.3V)
Push-Pull
RST2
.........................................-0.3V to (V
CC
2 + 0.3V)
RSTIN, PFI,
MR,
WDI ................................................-0.3V to +6V
Input Current/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 8.7mW/°C above +70°C) ........696mW
8-Pin SOT23-8 (derate 8.9mW/°C above +70°C) ........714mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature ......................................................+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 = V
CC
2 = 0.8V to 5.5V, GND = 0, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Supply Voltage
SYMBOL
V
CC
I
CC1
Supply Current
I
CC2
V
CC
1 < 5.5V, all I/O pins open
V
CC
1 < 3.6V, all I/O pins open
V
CC
2 < 3.6V, all I/O pins open
V
CC
2 < 2.75V, all I/O pins open
L (falling)
M (falling)
T (falling)
S (falling)
V
CC
1 Reset Threshold
V
TH1
R (falling)
Z (falling)
Y (falling)
W (falling)
V (falling)
T (falling)
S (falling)
R (falling)
Z (falling)
Y (falling)
W (falling)
V
CC
2 Reset Threshold
V
TH2
V (falling)
I (falling)
H (falling)
G (falling)
F (falling)
E (falling)
D (falling)
Reset Threshold Tempco
Reset Threshold Hysteresis
V
HYST
Referenced to V
TH
typical
4.500
4.250
3.000
2.850
2.550
2.250
2.125
1.620
1.530
3.000
2.850
2.550
2.250
2.125
1.620
1.530
1.350
1.275
1.080
1.020
0.810
0.765
CONDITIONS
MIN
0.8
15
10
4
3
4.625
4.375
3.075
2.925
2.625
2.313
2.188
1.665
1.575
3.075
2.925
2.625
2.313
2.188
1.665
1.575
1.388
1.313
1.110
1.050
0.833
0.788
20
0.5
TYP
MAX
5.5
39
28
11
9
4.750
4.500
3.150
3.000
2.700
2.375
2.250
1.710
1.620
3.150
3.000
2.700
2.375
2.250
1.710
1.620
1.425
1.350
1.140
1.080
0.855
0.810
ppm/°C
%
V
V
µA
UNITS
V
2
_______________________________________________________________________________________
Dual/Triple Ultra-Low-Voltage SOT23 µP
Supervisory Circuits
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
1 = V
CC
2 = 0.8V to 5.5V, GND = 0, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
V
CC
to Reset Output Delay
SYMBOL
t
RD
CONDITIONS
V
CC
1 = (V
TH
1 + 100mV) to (V
TH
1 - 100mV) or
V
CC
2 = (V
TH
2 + 75mV) to (V
TH
2 - 75mV)
D1
D2
Reset Timeout Period
t
RP
D3
D5
D6
D4
ADJUSTABLE RESET COMPARATOR INPUT (MAX6719/MAX6720/MAX6723–MAX6727)
RSTIN Input Threshold
RSTIN Input Current
RSTIN Hysteresis
RSTIN to Reset Output Delay
PFI Input Threshold
PFI Input Current
PFI Hysteresis
PFI to
PFO
Delay
t
RSTIND
V
PFI
I
PFI
V
PFH
t
DPF
V
IL
V
IH
0.7
✕
V
CC
1
1
100
t
MR
25
First watchdog period after reset timeout
period
Normal mode
WDI Pulse Width
WDI Input Voltage
WDI Input Current
t
WDI
V
IL
V
IH
I
WDI
WDI = 0 or V
CC
1
0.7
✕
V
CC
1
-1
+1
(Note 2)
200
50
80
(V
PFI
+ 30mV) to (V
PFI
- 30mV)
V
RSTIN
to (V
RSTIN
- 30mV)
611
-25
3
2
0.3
✕
V
CC
1
V
RSTIN
I
RSTIN
611
-25
3
22
626.5
642
+25
626.5
642
+25
mV
nA
mV
µs
mV
nA
mV
µs
1.1
8.8
140
280
560
1120
MIN
TYP
20
1.65
13.2
210
420
840
1680
2.2
17.6
280
560
1120
2240
ms
MAX
UNITS
µs
MAX6715–MAX6729
POWER-FAIL INPUT (MAX6728/MAX6729)
MANUAL RESET INPUT (MAX6715–MAX6722/MAX6725–MAX6729)
MR
Input Voltage
MR
Minimum Pulse Width
MR
Glitch Rejection
MR
to Reset Delay
MR
Pullup Resistance
WATCHDOG INPUT (MAX6721–MAX6729)
Watchdog Timeout Period
t
WD
35
1.12
50
0.3
✕
V
CC
1
54
1.68
72
2.24
ns
V
µA
s
V
µs
ns
ns
kΩ
_______________________________________________________________________________________
3
Dual/Triple Ultra-Low-Voltage SOT23 µP
Supervisory Circuits
MAX6715–MAX6729
ELECTRICAL CHARACTERISTICS (continued)
(V
CC
1 = V
CC
2 = 0.8V to 5.5V, GND = 0, T
A
= -40°C to +85°C, unless otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
RESET/POWER-FAIL OUTPUTS
V
CC
1 or V
CC
2
≥
0.8V, I
SINK
= 1µA,
output asserted
V
CC
1 or V
CC
2
≥
1.0V, I
SINK
= 50µA,
output asserted
RST/RST1/RST2/PFO
Output LOW
(Push-Pull or Open-Drain)
V
OL
V
CC
1 or V
CC
2
≥
1.2V, I
SINK
= 100µA,
output asserted
V
CC
1 or V
CC
2
≥
2.7V, I
SINK
= 1.2mA,
output asserted
V
CC
1 or V
CC
2
≥
4.5V, I
SINK
= 3.2mA,
output asserted
V
CC
1
≥
1.8V, I
SOURCE
= 200µA, output not
asserted
RST/RST1/PFO
Output HIGH
(Push-Pull Only)
V
OH
V
CC
1
≥
2.7V, I
SOURCE
= 500µA, output not
asserted
V
CC
1
≥
4.5V, I
SOURCE
= 800µA, output not
asserted
V
CC
2
≥
1.8V, I
SOURCE
= 200µA, output not
asserted
RST2
Output HIGH
(Push-Pull Only)
V
OH
V
CC
2
≥
2.7V, I
SOURCE
= 500µA, output not
asserted
V
CC
2
≥
4.5V, I
SOURCE
= 800µA, output not
asserted
V
CC
1
≥
1.0V, I
SOURCE
= 1µA, reset asserted
RST
Output HIGH
(Push-Pull Only)
V
CC
1
≥
1.8V, I
SOURCE
= 150µA,
reset asserted
V
OH
V
CC
1
≥
2.7V, I
SOURCE
= 500µA,
reset asserted
V
CC
1
≥
4.5V, I
SOURCE
= 800µA,
reset asserted
V
CC
1 or V
CC
2
≥
1.8V, I
SINK
= 500µA,
reset not asserted
RST
Output LOW
(Push-Pull or Open Drain)
V
OL
V
CC
1 or V
CC
2
≥
2.7V, I
SINK
= 1.2mA,
reset not asserted
V
CC
1 or V
CC
2
≥
4.5V, I
SINK
= 3.2mA,
reset not asserted
Output not asserted
Output asserted
0.8
✕
V
CC
1
0.8
✕
V
CC
1
0.8
✕
V
CC
1
0.8
✕
V
CC
2
0.8
✕
V
CC
2
0.8
✕
V
CC
2
0.8
✕
V
CC
1
0.8
✕
V
CC
1
0.8
✕
V
CC
1
0.8
✕
V
CC
1
0.3
0.3
0.4
0.5
0.5
µA
µA
V
V
V
V
0.3
0.3
0.3
0.3
0.4
V
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
RST/RST1/RST2/PFO
Output
Open-Drain Leakage Current
RST Output Open-Drain
Leakage Current
Note 1:
Devices tested at +25°C. Overtemperature limits are guaranteed by design and not production tested.
Note 2:
Parameter guaranteed by design.
4
_______________________________________________________________________________________
Dual/Triple Ultra-Low-Voltage SOT23 µP
Supervisory Circuits
MAX6715–MAX6729
Typical Operating Characteristics
(V
CC
1 = 5V, V
CC
2 = 3.3V, T
A
= +25°C, unless otherwise noted.)
SUPPLY CURRENT vs. TEMPERATURE
V
CC
1 = 5V, V
CC
2 = 3.3V
MAX6715-29 toc01
SUPPLY CURRENT vs. TEMPERATURE
V
CC
1 = 3.3V, V
CC
2 = 2.5V
MAX6715-29 toc02
SUPPLY CURRENT vs. TEMPERATURE
V
CC
1 = 2.5V, V
CC
2 = 1.8V
16
SUPPLY CURRENT (µA)
14
12
10
8
6
4
2
0
I
CC
2
I
CC
1
TOTAL
MAX6715-29 toc03
18
16
SUPPLY CURRENT (µA)
14
12
10
8
6
4
2
0
-40
-15
10
35
60
I
CC
2
TOTAL
I
CC
1
18
16
SUPPLY CURRENT (µA)
14
12
10
8
6
4
2
0
I
CC
2
I
CC
1
TOTAL
18
85
-40
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
TEMPERATURE (°C)
SUPPLY CURRENT vs. TEMPERATURE
V
CC
1 = 1.8V, V
CC
2 = 1.2V
MAX6715-29 toc04
NORMALIZED RESET/WATCHDOG
TIMEOUT PERIOD vs. TEMPERATURE
MAX6715-29 toc05
MAXIMUM V
CC
TRANSIENT DURATION
vs. RESET THRESHOLD OVERDRIVE
MAXIMUM V
CC
TRANSIENT DURATION (µs)
RESET OCCURS ABOVE
THIS LINE
1000
MAX6715-29 toc06
18
16
SUPPLY CURRENT (µA)
14
12
10
8
6
4
2
0
-40
-15
10
35
60
I
CC
2
TOTAL
I
CC
1
1.007
1.006
RESET/WATCHDOG PERIOD
1.005
1.004
1.003
1.002
1.001
1.000
0.999
0.998
10,000
100
85
10
-40
-15
10
35
60
85
1
10
100
1000
TEMPERATURE (°C)
RESET THRESHOLD OVERDRIVE (mV)
TEMPERATURE (°C)
NORMALIZED V
CC
RESET THRESHOLD
vs. TEMPERATURE
MAX6715-29 toc07
RESET INPUT AND POWER-FAIL INPUT
THRESHOLD vs. TEMPERATURE
MAX6715-29 toc08
V
CC
TO RESET DELAY
vs. TEMPERATURE
53
V
CC
TO RESET DELAY (µs)
52
51
50
49
48
47
46
45
100mV OVERDRIVE
MAX6715-29 toc09
1.004
1.003
1.002
RESET THRESHOLD
1.001
1.000
0.999
0.998
0.997
0.996
-40
-15
10
35
60
631
630
THRESHOLD (mV)
629
628
627
626
625
54
44
-40
-15
10
35
60
85
-40
-15
10
35
60
85
TEMPERATURE (°C)
TEMPERATURE (°C)
85
TEMPERATURE (°C)
_______________________________________________________________________________________
5
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