19-0536; Rev 3; 9/08
Dual/Triple, Ultra-Low-Voltage, SOT23 µP
Supervisory Circuits
15–2/MX697A
General Description
Features
The MAX6715A–MAX6729A/MAX6797A are ultra-low-volt-
age microprocessor (µP) supervisory circuits designed to
monitor two or three system power-supply voltages. These
devices assert a system reset if any monitored supply falls
below its factory-trimmed or adjustable threshold and main-
tain reset for a minimum timeout period after all supplies rise
above their thresholds. The integrated dual/triple supervisory
circuits significantly improve system reliability and reduce
size compared to separate ICs or discrete components.
o V 1 (Primary Supply) Reset Threshold Voltages
CC
from 1.58V to 4.63V
o V 2 (Secondary Supply) Reset Threshold
CC
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
These devices monitor primary supply voltages (V 1)
CC
from 1.8V to 5.0V and secondary supply voltages (V 2)
CC
o Manual-Reset Input Option
from 0.9V to 3.3V with factory-trimmed reset threshold
voltage options (see the 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 cor-
o Power-Fail Input/Power-Fail Output Option
(Push-Pull and Open-Drain Active-Low)
o Guaranteed Reset Valid Down to V 1 or
CC
V 2 = 0.8V
CC
rect reset output logic state when either V 1 or V
CC
2
CC
o Reset Output Logic Options
o Immune to Short V
remains greater than 0.8V.
Transients
CC
A variety of push-pull or open-drain reset outputs along
with watchdog input, manual-reset input, and power-fail
input/output features are available (see the Selector
Guide). Select reset timeout periods from 1.1ms to
1120ms (min) (see the Reset Timeout Period Suffix
Guide). The MAX6715A–MAX6729A/MAX6797A are avail-
able in small 5-, 6-, and 8-pin SOT23 packages and oper-
ate over the -40°C to +125°C temperature range.
o Low Supply Current 14µA (typ) at 3.6V
o Watchdog Disable Feature
o Small 5-, 6-, and 8-Pin SOT23 Packages
Ordering Information
PIN-
PACKAGE
PART
TEMP RANGE
Applications
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
-40°C to +125°C
MAX6715AUT_ _D_+T
MAX6716AUT_ _D_+T
MAX6717AUK_ _D_+T
MAX6718AUK_ _D_+T
MAX6719AUT_ _D_+T
MAX6720AUT_ _D_+T
6 SOT23
Multivoltage Systems
Telecom/Networking
Equipment
Computers/Servers
Portable/Battery-
Operated Equipment
Industrial Equipment
Printers/Fax Machines
Set-Top Boxes
6 SOT23
5 SOT23
5 SOT23
6 SOT23
6 SOT23
+Denotes a lead-free/RoHS-compliant package.
T = Tape and reel.
Typical Operating Circuit
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
OUT2
DC-DC
CONVERTER
OUT1
UNREGULATED
DC
IN
1.8V
I/O
0.9V
CORE
V
1
V
2
CC
CC
SUPPLY SUPPLY
MAX6716AUTLTD3-T is a dual-voltage supervisor V 1 =
MAX6715A-
MAX6729A/
MAX6797A
TH
R1
4.625V, V 2 = 3.075V, and 210ms (typ) timeout period.
TH
RESET
RST
WDI
PFO
µP
RSTIN/PFI
MR
I/O
NMI
Ordering Information continued at end of data sheet.
R2
MAX67_ _
PUSHBUTTON
SWITCH
Pin Configurations and Selector Guide appear at end of
data sheet.
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.